Actual questions with answers presented to Master Gardeners at clinics in our community covering a wide range of gardening topics. Some are quite unique while others more frequently posed. The following responses have been researched by members of the Victoria Master Gardener Association (VMGA). Check back on a regular basis to find new questions presented each month.
This cedar tree has rectangular chunks chipped out of it. What caused this damage?
This damage to the cedar tree was caused by a pileated woodpecker (Dryocophus pileatus). The Pileated Woodpecker is one of the biggest and most striking forest birds. Itís nearly the size of a crow and has a flaming-red crest. Pileated Woodpeckers drill distinctive rectangular-shaped holes in wood to get at carpenter ants and other insects that are inside the tree. The fact that insects are inside the tree likely indicates that the tree is either dead or dying. These holes can be so large that they weaken smaller trees or even cause them to break in half.
Should I cut the stalk down on my orchid now that the flower has faded? Should I cut the bruised looking roots?
When your orchid is still blooming, remove each flower as it fades. Using sharp pruning shears or a straight edged razor blade to cut back the flower to the main branch. Once the orchid is completely finished blooming, it is time to do the major pruning. If your orchid is a Phalaenopsis orchid, it is possible to get a re-bloom from its old spike (stem) as long as it is still a healthy green colour. Cut the stem off leaving two nodes, one of these nodes will then initiate and generally produce flowers within 8-12 weeks. If there are any places on the stalk that have turned yellow or brown it is an indication that it will not bloom again so just cut the spike off completely about one inch above its base. Many orchid growers do not recommend trying to bloom a Phalaenopsis orchid more than once from the same spike, because blooming your orchid repeatedly can exhaust the plant. Instead, cutting it all the way back (to one inch above base) will encourage stronger growth and larger blooms. If your orchid is a Dendrobium orchid, trim the flowers off as they fade but do not cut down the stem. Next year it will flower on the same stalk. Next, replant the orchid into a bigger pot in order to allow it more room to grow. When doing this you have the chance to cut off any bruised, dead, or damaged roots.
Should I use tomato fertilizer on my Agapanthus now? What protection should I use on them over the winter? How can I make them bloom longer?
Agapanthus thrive in well-drained soil in a sunny location. Lots of sun is key to bigger and longer blooms. Shadier locations will result in more green lush foliage growth but less blooms. Make sure Agapanthus is in full sun to maximize flowering. Agapanthus is a heavy feeder and does best with organic compost worked into the soil at planting and fertilizer during its growing period. Knowing when and what to fertilize with will ensure big healthy blooms. Avoid fertilizing with high nitrogen fertilizers in spring because it will force new leafy growth at the expense of flowering. Instead, fertilize agapanthus in early spring, just prior to the beginning of the blooming season using a balanced fertilizer with a ratio such as 10-10-10 or 5-5-5. If you have soil that is already balanced or high in nitrogen, you should use a fertilizer that is slightly lower in nitrogen and higher in phosphorus such as a 5-10-5 or a 5-10-10 mixed fertilizer. Feed agapanthus again in midsummer. Agapanthus grown outdoors will die back in winter. Spread a dry mulch of sand or straw around the root zone to protect the plant from the cold. Apply a 6-9 inch deep layer around the plants in autumn or early winter and remove in spring before growth starts. Alternatively, in cooler areas, dig up the bulbs and pot up the plant to grow indoors during winter. Plants kept outside that are dormant do not need fertilizer until they begin to sprout anew. Consistent watering is also key to producing big beautiful and longer blooms so ensure you have a good irrigation system during the dry season.
Do I cut down my everbearing raspberries now?
The common method of pruning everbearing raspberries is to simply cut all of the canes down to about 1 inch from the ground. Even though this is an easy way to go, this method eliminates the July crop. Fruiting doesnít begin until early fall which is the reason some raspberry growers call everbearing raspberries ìfall bearingî. Some people prefer to use this method to force their everbearing raspberries to produce only one crop because it produces a larger fall harvest and is good if you also have summer bearing raspberry bushes and you want to stagger the harvests. If you want fruit in both the summer and fall from your everbearing raspberries you need to use a slightly different approach. In the spring cut the 1-year-old canes back to just below the fruiting area, approximately level with the top support wire or down by about one-third. These shortened canes will begin fruiting in July. Then during the spring and summer new canes will grow up from between the old canes and these new canes will flower and fruit later in the summer. Then, the next spring remove all 2-year-old canes complete (cut them off at the ground) and trim back the 1-year-old canes as described previously. In terms of exactly when you do your pruning, winter is best because the berry canes are fully dormant. Any time between November and March is also fine.
I have lost all my grapes to raccoons! How do I keep them away?
There is a lot of advice out there about eliminating raccoon attractants (e.g., no bird feeders, no outdoor pet food, secured trash lids) or deterring with a wide variety of things such as loud radio noise or motion sensors attached to water jets, lights, or buzzers, or using sprays such as coyote urine, pepper or mint around the property. Another suggestion is scattering blood meal around the property, or grinding up garlic and chill powder and spreading it around the property. Leaving a bright light on all night will sometimes keep sun-shy raccoons away. But in reality these things make little difference. Raccoons are very smart and quickly figure out ways around them. Another piece of advice is to try to trap the raccoons, but they may not be that easy to catch and even if you have success once, you still need to deal with new raccoons that keep moving into the area, meaning this isnít a long term solution. The two most effective options to keep raccoons from your grapes are containing the grapes within a secure enclosure or using an electric fence. Securing them inside a closed greenhouse that guarantees their protection will also increase fruit production. Adding a greenhouse is not always desirable or a feasible option so the second option is to install an electric fence around the grapes. Raccoons can be deterred with a two-wire fence, with one wire four to six inches above the ground and the other at 12 inches.
What is wrong with my tomato? The tomato has a brown leathery scab covering the bottom.
The tomato is showing the early signs of late blight. Pull out the affected plant and carefully watch the fruit on the rest of the crop. Apparently, the plants are under plastic and the recent rain could not have splashed the foliage of the plant so this is puzzling. Try picking all the green tomatoes and bringing them indoors to ripen and this may prevent a further outbreak of this fungus. Indoor ripening is easily done by placing the tomatoes in a single layer on cardboard in a garage or other dry location.
Natural Insect, Weed & Disease Control by Linda A. Gilkeson
What was eating the leaves of my Viburnums earlier in the summer?
The culprit was probably the Viburnum beetle. There are several ways to lessen the impact of the beetles. Carefully inspect the plant between October and April and prune out any egg laying twigs. This is most easily done when the plant has lost its leaves. Encourage generalist predators such as larvae and adult lady beetles, lacewing larvae and spiny soldier beetles as these feed on the beetles. Plant a broad mix of plants in your garden to provide a diverse habitat for the insects. Recent research has also indicated that the Viburnum larvae crawl down the plant to pupate in the soil and it is thought that putting sticky barrier likeTanglefoot around the base of the plant may prevent them from reaching the soil. Spraying the plant with a 4% solution of horticultural oil once the leaves have dropped is also very effective. Viburnum species such as V. davidii, rhydophyllum, lantana and burkwoodii are not usually attacked by the beetle.
The leaves of my Rhododendrons have a notched appearance. What is eating them?
The leaves have been attacked by the Black vine weevil. Probably the easiest way to control the impact of this bug is to apply parasitic nematodes. These are mixed with water and applied around the base of the plant. They require moist soil and warm conditions to be effective, so apply now. Be sure to keep the soil around the plant moist at all times until our fall rains start.
I have a lot of wood bugs in my compost. How can I control them?
Did you know that wood bugs or sow bugs are actually not insects all but crustaceans? Their presence in the compost indicate that the compost is a bit on the dry side as they do not like wet conditions. You should add some water to help the material break down more quickly. Sow bugs are actually beneficial in the compost as they consume bulky and tough material, making it easier for the microbes to break down. To help your compost break down more quickly, you should turn it as much as possible and keep it moist. If you are using an open compost bin, covering the bin with a tarp or a plywood cover will keep your compost from going soggy and stagnant over the winter, and although slower, the microbes will still be working to break down the material into compost.
My white hydrangea went brown early in the summer. What caused this?
The most likely cause for the flowers turning brown is heat stress. Hydrangeas do best when planted in an area with dappled shade to protect them from the hot summer sun. The plants also need consistent watering so the soil does not dry out and the plant is kept well hydrated.
Something is digging in my garden. Is it squirrels or raccoons?
It could be either or even crows or ravens! Squirrels are often digging to bury nuts for the winter and they also love to dig up newly planted tulip bulbs and eat them. To avoid them digging up your tulips, lay down a small piece of chicken wire on top the newly planted area and cover it with mulch. This will prevent them from being able to dig up the bulbs. Raccoons are also active this time of year and they too are caching food, including apples. They also dig for juicy grubs in the soil. I have even seen ravens collect nuts from the hazelnut tree and bury them in the soil.
What is the best fig to grow in our climate? Can I grow it in a container?
Figs that produce a good crop in our area are 'Desert King'and 'Brown Turkey'. Figs grow well in very large containers such as half a wine barrel. You will need to water regularly and fertilize to the plant while it is actively growing.
Why did my peach not flower this year? It is espaliered on the south west side of the house and gets lots of sunlight.
Young peach trees often need a year or two to get established. Make sure that when you are pruning, you do not cut off all the new shoots, as the next yearís crop of peaches is produced from this yearís wood. Trees espaliered against foundation walls and protected by an overhanging roof line will need to be watered regularly, even during the winter to keep the roots moist. Since the building code requires foundation walls have a series of drainage pipes, this area dries out very quickly.
Why did my 'Seascape' and 'Albion' varieties of ever-bearing strawberries not produce very well and why were the berries pretty small?
Strawberries are very heavy feeders and need to be planted in soil that is raised for good drainage and amended with lots of well-rotted manure and fertilized over the growing season. It is vital that the roots are watered regularly during our hot dry summers. Strawberries need to be transplanted to a new location every three years. This is best done in the fall by moving runners into the well prepared location.
I have a camellia bush and the buds have turned brown. Why?
There can be several reasons for buds to turn brown and drop. 1) Buds on camellias start to develop in late summer of the previous year. If there are adverse conditions including dry soil this can result in buds turning brown and dropping. Ensure your plant has an adequate supply of water during these critical times of the year. 2) Excessive or late feeding can cause buds to drop. Avoid feeding after July. 3) If you have a sensitive cultivar, low winter temperatures can cause buds to turn brown and drop. If temperatures drop unseasonably protect camellia with horticultural fleece.
Are tomatoes self fertile?
Tomato flowers do not need bees to pollinate but if grown under cover, improve pollination by gently tapping or shaking the flower truss.
West Coast Seeds 2017- pg 73
Step-by-Step Gardening Techniques, Arch Cape Press pg 245
There are brown and grey spots on my begonias. They are spreading, what are they and what should I do?
Botrytis (Botrytis cinerea) is a fungus and gets into plants through injured tissue or dying blossoms. Spores over winter and spread by air currents and wind. Infected plants should be destroyed (not composted) To prevent botrytis, ensure plants have good air circulation, allow soil surface to dry between watering and water early in the day so foliage can dry by nightfall.
Natural Insect, Weed & Disease Control, Linda Gilkeson pg 137
I have just moved into the area and have lots of horsetail on my property. What do I do?
Horsetail are a spore-bearing plant in the family Equisetaceae. Horsetail are native to the Pacific Northwest. Organic mulches won't work to remove horsetail as spears grow through most material. Improving drainage, raising the pH of soil and increasing soil fertility will help to permanently eliminate horsetail. Use heavy material (cardboard/tarps), that exclude light, to slow growth. As nitrogen does not speed or spread the growth of horsetails, using fertilizer to support and encourage desirable plants can be an effective way to shift horsetail.
Natural Insect, Weed & Disease Control, Linda Gilkeson pg 185
I have cucumbers with yellowing leaves that are falling off. Whatís wrong with my plant?
The cucumber plants are likely suffering from a nitrogen, magnesium deficiency. Liquid fish fertilizer is a good source of nitrogen, blood meal is an excellent high nitrogen fertilizer for organic garden. Use application rate on box (approx. 2-4 kgs per 10 sq. meters). Epsom salts (20g per litre of water) can be used as a foliar feed to counter magnesium deficiency.
Backyard Bounty, Linda Gilkeson pg 57
My Iris plant leaves have black spots. What is this?
Iris diseases can be caused by fungi, bacteria or viruses. Iris leaf spot, a fungal disease (Didymellina macrospora), occurs primarily in leaves and manifests in brown centres with yellow margins. The spots produce spores which cause the disease to buildup and spread. To control remove and destroy spotted or dead plant material. Plant iris in full sun and space at least 20 cms (8íí) apart. Spacing irises in this manner increases air circulation around leaves and provides room for growth.
Why are my irises not blooming?
Irises require well draining soil in full sun. In this particular situation, it may be that the irises did not bloom as a result of a very wet winter and spring. Overcrowding can cause poor blooming as well. An annual application of a fertilizer of 5-10-10 would be useful.
Why do I have Leatherjackets (crane flies)in my lawn?
Unseasonably wet winter and spring can cause this situation. The larvae stage of Leatherjackets is prolonged in wet conditions.
I have rhododendrons that have not bloomed in years. What can I do to get them to bloom again? Can I prune my rhodos?
The most common cause for lack of blooms is not enough light. This inhibits their ability to produce energy from photosynthesis for blooms. You can also try rejuvenating a straggly rhodo over a period of 2-3 years. Cut above a node on the branch. Remove straggly, twiggy growth. Pinch out all single terminal buds. Feed and mulch around the drip line. For large-leafed rhodos, cut to just above a whorl of leaves. The best time to prune is right after flowering. When the plant is re-established, prune and tidy annually after blooming to keep the rhodo looking fresh.
Rhododendrons & Azaleas by Kenneth Cox
My rhododendron has pale leaves. What could be wrong?
This is called chlorosis. Pale leaves are a sure sign of poor soil conditions. Ideally rhodos like a pH of 4-6. High pH affects the availability of essential elements such as iron and also affects the health of microorganisms. Alkaline soils take in too much calcium hindering photosynthesis. A soil of predominantly peat or leaf mould is recommended. To improve the pH of the soil, ferrous sulphate can be sprinkled on top or sulphur dug throughout the soil.
Rhododendrons and Azaleas by Kenneth Cox
How do I control St. John's Wort?
St. Johnís Wort is considered a noxious weed in many areas. Small areas can be handled by digging and pulling, however this can take months. You can continue to attack the weed with a weed whacker to lessen the spread. Get rid of St. Johnís Wort before it produces flowers. It is recommended to burn the weeds after pulling.
How do I control my bamboo?
The gardener needs to determine the type of bamboo they are growing, whether it is running or clumping bamboo. Running bamboo roots are very shallow. Root prune once a year. Have the ground wet so the digging required is easier. Next, stab a pick ax into the soil at the perimeter of the bamboo grove to hook any rhizomes that are escaping. If your soil is wet enough, tilting the pick ax away from you will bring the rhizomes to the surface. Once pulled, decide whether you want to cut it or replant it for future plants. It is best to cut the current season rhizomes now before they have time to establish. The best time to root prune is in the fall.
Can I prune my cedar trees to keep them short?
Assuming the cedar trees are of the hedge-type, do not let a hedge grow more than 6î a year. Trimming is best in September to give the plants time to recover before fall and winter. Cedars will not regenerate new growth from old wood. Tops of cedars can be cut down by over 12î with no obvious damage.
Why is my arbutus tree in decline?
The arbutus tree: Arbutus menziesii. This tree is the only broadleaf evergreen tree in Canada and the least frost resistant. In a cold winter when frost occurs before the Arbutus has hardened off, foliage, branches and buds may be killed outright. Winter damaged tissue may be more susceptible to attack by pests. It grows in a wide range of soils provided they are well-drained. Winter-killed branchlets should be pruned and dead leaves removed so they do not act as a reservoir for disease. Spores infecting new foliage come from existing stem and leaf lesions on older foliage in the tree or on the ground. These worsen in wet weather.
My daffodils haven't bloomed, why might this be?
There are a variety of reasons why daffodils may fail to bloom. Firstly, location is key; daffodils require at least a half day of full sun in winter in order to produce flowers (full day sun is ideal). The more sun the more energy the bulb has to produce a bloom. The next possible reason is the type of daffodil. Heirloom daffodils that have been around for 75 or more years bloom faithfully for decades (e.g., Grand Primos and Campernelles), whereas non-heirloom varieties are weaker genetically and over the long run fail to thrive. Weaker genes usually generate large blooms for 4-6 years and after that time end up as mostly clumps of foliage (e.g., Carlton and Ice Follies). Another possible reason could be planting depth. The bulbs should be planted 2-3x its bulb height. If planted too shallow, there can be at risk of freezing or overheating. These inhospitable conditions can effect reformation of the bulb. Interestingly, another possible cause of decreased blooms can be over fertilization. Nitrogen-rich fertilizer triggers green growth and over feeling causes only the green leafy parts of the plant to grow. When fertilizing bulbs use a low nitrogen fertilizer (e.g., 5-10-10, or 10-20-20) and fertilize when planting and then again at bloom. Also, consider the soil conditions. Most narcissus such as daffodils prefer slightly acidic soil and good drainage. If drainage is poor, they can suffer from basal rot which is incurable - dig and discard the bulbs if rot is found. Another possibility is that the bulbs may be stressed from transplanting. Some varieties seem to skip a year of blooming if they were dug and replanted. Also, be sure not to cut back the daffodils too soon. Daffodils replenish their bulb for about six weeks after they bloom, if cut back too soon they may not bloom the next year. And one final possibility could be that, if the bulbs have been growing in the same spot for many years, they require dividing. If left in one place and not divided the bulbs become compacted in clumps that are competing for food and space and tend to cease blooming. Separate them into individual bulbs and plant spaced apart approximately 6 inches.
When should I prune my Ribes?
The Ribes (flowering currant) flower early in the spring - just after Forsythia. Because Ribes flower from buds grown in the previous season the timing of pruning is important. They must be pruned immediately after flowering as the plant requires a full season to grow the flower stems and buds for the next spring. If the Ribes is pruned late the flower buds for the next year will be lost and therefore it won't flower the next spring. Firstly, when pruning, cut out any damaged/dead/diseased branches. Next take out any weak, spindly, or twiggy shoots. Then continue depending on the result you would like. A few options for pruning exist depending on desired size and shape. Pruning can either be a general trim back, focusing on cutting back the flowered growth down to strong young shoots and each year cutting off 20% of ageing stems to near the base. Another option is cutting the Ribes back very hard each year (again make sure it is right after flowering) to a height of 30cms from the ground. If pruned back in this manner each year, the shrub will stay a reasonable size and also the plant will grow long upright cane type branches during the year which will be covered from top to bottom in large flower clusters the next spring which is spectacular!
I found thousands of white specks in my compost bin. What could this be?
These are probably mites. Mites are always present in worm bins/compost bins as they love to feed on decaying matter, and you do not need to do anything unless there is an infestation. Their populations are usually kept in check, but if the conditions are right they may get out of control. Dramatic increases in mite populations are almost always caused by too much water or overfeeding. Mites thrive in excessively moist and acidic conditions, and because they feed on decaying matter they love places such as compost bins. An excessively wet bin creates conditions that are more favourable to mites than to earthworms and too much food can cause a buildup of fermented feed which lowers the pH of the compost pile. So, as a solution try to leave the lid off your bin to allow excess moisture to evaporate and try adding a calcium supplement (e.g., calcium carbonate, rock dusts) to help raise the pH levels. Also, slow down feeding schedules, and be sure all the freshly added material has been consumed by the worms in a few days. But don't be too alarmed, unlike red mites that are parasites of earthworms, these white mites may compete with earthworms for available food but they do not directly harm or prey on them.
I'd like to plant vegetables in plastic containers. What type of soil should I use?
Soils for containers need to be well aerated and well drained while still being able to retain enough moisture for plant growth. When choosing what to use to fill containers, never use just garden soil (even if it is excellent garden soil) because when put into a container both drainage and aeration are severely impeded and the plants will not thrive. Soils for containers are always modified to ensure proper drainage and aeration. Local nurseries have bagged mixes designed for use in outdoor containers, or save money by blending your own vegetable container garden mix. You need three basic ingredients and use them in equal proportions. First the growing medium (bagged sterilized garden soil), moisture retention (peat moss or coconut coir), and drainage (use perlite, vermiculite, or sand). Mix the three ingredients in equal proportions. Fertilizing homemade potting soil is also important. You can amend your pots by top-dressing with compost or use a slow release organic fertilizer in order to steadily feed your plants.
When should I prune my apple trees?
Apple trees should be pruned in late winter, but you can prune into the spring and summer if you must. Ideally pruning should occur when the tree is dormant (between leaf fall and bud burst). Avoid pruning in the fall since this stimulates new growth at the same time as the tree is preparing for winter. You should prune your apple tree every winter to ensure a good cycle of fruiting wood. Trees that arenít pruned become less productive and congested with old branches.
Few things are as beneficial to a fruit tree as regular pruning. The goal is to create an open goblet shape with a framework of 4-5 main branches. Always start your pruning by removing crossing, rubbing, weak, dead, diseased, damaged and dying branches. Then shorten the previous yearís growth on each main branch by about 1/3 to a bud facing in the required direction. Leave young laterals (side-shoots) unpruned so they can develop fruit buds the second year. Prune out upward growing branches (water sprouts) as they drain too much energy from the main limb and can quickly get out of control. On older trees remove congestion, thin as required to let light reach all developing fruit. As a side note, if you have a tree that is too vigorous you can consider also carrying out summer pruning in order to reduce vigour.
Should I prune my Oakleaf Hydrangea now?
Hydrangea quercifolia - or Oakleaf hydrangeas - are deciduous shrubs with attractive bark and deeply lobed mid-green leaves that turn bronze-purple in the fall. They bear conical panicles of white flowers from mid-summer to autumn. Some cultivars can grow to six feet, although there are smaller varieties. These hydrangeas are best grown in a protected site as there may be some stem and bud damage if temperatures dip below - 10 degrees.
This shrub requires minimal pruning - less is often better. However, removing wayward, crossing or dead branches is beneficial - and these can be removed to he ground or to a main branch. The plant may also need shaping or reducing in size and pruning can help improve the shrubs vigour and prevent floppiness.
Hydrangea quercifolia blooms on OLD WOOD.
There is conflicting information on WHEN best to prune. However, the consensus is:
1. Pruning in early autumn, right after the plant finishes blooming, is best.
2. If this time has passed, pruning in late winter/early spring when the plant is dormant is also fine.
American Horticultural Society A - Z Encyclopedia
Sunset Western Garden Book
The Pruners Bible by Steve Bradley
There are many youtube videos of how to prune hydrangeas such as
What are the ideal conditions for growing hellebores?
Helleborus is a genus of 15 species of perennials that belong to the Ranunculus family. They are long-lived plants that add colour to the garden for several months in winter and early Spring. They have attractive foliage, beautiful blooms and are usually ignored by the deer and rabbits.
CONDITIONS: Choose a site carefully as hellebores should not be disturbed once planted. They resent being moved and if this is necessary they may take two or more years to re-establish and bloom. Hellebores prefer a semi-shaded site - ideally early sun with protection from hot afternoon rays. If planted in deep shade flowering may be reduced.
A well-drained soil which is somewhat alkaline is ideal. H. niger (the Christmas rose) insists on alkaline soil, but other cultivars are more forgiving. Lots of organic matter is desirable.
It is crucial NOT to plant hellebores too deep. their crown should not be buried. Cutting the dead leaves off in late winter is said to improve the blooms. They should be fed once or twice a year with a balanced fertilizer containing blood and bone meal among other nutrients (availbale from Borden's, Integrity, and other suppliers).
H. niger (Christmas rose) blooms in November and possibly may still have blooms to grace the Christmas table. Most other species bloom in very early spring and the blooms can last up to two months.
American Horticultural Society A - Z Encyclopedia
Sunset Western Garden
How much should I cut my Jackmanii Clematis?
Clematis is a genus of about 300 species within the buttercup family Ranunculaceae. The plants are primarily deciduous vines, although a few are evergreen.
There are at least three Jackmanii cultivars, and all three belong to the large-flowered hybrid group. The most common, and classic, Jackmanii clematis is a LATE, large-flowered cultivar. C. Jackmanii blooms in late summer with abundant, single, velvety dark purple flowers with prominent yellow stamens. This cultivar was introduced in 1858, the first of the large-flowered hybrid clematis.
Jackmanii is a TYPE 3 clematis. Clematis in this group are later season (summer) bloomers and flower from buds developed in the current season.
So cut back ALL the previous year's stems to a pair of strong buds, 6 - 12 inches above soil level, BEFORE growth begins in early Spring.
American Horticultural Society A - Z Encyclopedia
Sunset Western Garden Book
Pruner's Bible by Steve Bradley
I want to purchase a lemon or orange tree. What size should I purchase and where should it be grown?
Your choices will depend greatly on WHERE you are going to grow the trees - indoors (in a greenhouse or conservatory) or outdoors; and WHY you are growing the tree - for a fruit crop or a decorative tree.
Oranges generally need a warmer greenhouse or shelter in this climate; while lemons and limes can be grown outdoors in specific locations. These tender fruits need to be grown on a south or southwest facing wall, with some way of protecting them should the temperature drop below freezing (i.e., covering them with a gardening fabric and warming with strings of non-LED 7 watt Christmas lights in the branches). Lemons and limes can be productive in the Pacific Northwest.
Always purchase a tree with a healthy root system. Ask if the plant can be lifted from the pot so you can see that the roots have not "circled" the pot. If the roots have circled themselves, this indicates that the plant has been in the pot for a long time and the plant is unlikely to be healthy and robust.
The size you choose will depend on how much you wish to spend, and is not always an indication of health and vigour (i.e. bigger is not always better).
We STRONGLY suggest that this person speak to and/or visit Mr Bob Duncan at Fruit Trees and More in North Saanich (www.fruittreesandmore.com)
. He grows all of these trees, has many for sale and is an expert about their needs.
I came back from vacation and my lemon and orange trees had leaves all curled up. What is wrong?
There are a few possible reasons why this may have happened:
1. The trees got too cold for too long: When the winter here has a prolonged period of pretty cold weather, these tropical plants may suffer. If your tree was not in a greenhouse or did not have adequate protection outside, they may have suffered cold damage.
2. Lack of water: If the leaves are of the usual green colour and are curling inward this may be a sign of a lack of water.
3. Pest attack: Aphids, spider mites, leaf miners, mealybugs and scale insects are common sap-sucking pests. They feed on citrus leaves and suck the sap from the tissues causing deformities such as curling, wilting, and discolouration. Cut off any damaged, curled leaves and spray with an insecticidal soap or horticultural oil.
4. Fungal diseases such a Bacterial Blast or Botrytis may attack these trees. Apply a copper fungicide before it rains.
Sunset Western Garden Book
I want to purchase roses and I don't know which type to buy.
This is a big question! I would need to know where you were thinking of planting your rose(s) and what kind and colours do you like. For example, there are climbing roses (which need something to climb on like a pergola or a trellis or a tree), shrub roses, groundcover roses, miniature roses for pots and many different flower types and fragrance strengths.
There are two huge groups of roses:
1. old garden roses - in existence before 1867
2. all species and modern roses introduced since 1867.
All the ones mentioned above would fall into this category.
All roses need LOTS of sun. Most are heavy feeders (i.e. need fertilizing) and most require pruning. It is best to choose varieties that are resistant to the common rose afflictions - like black spot.
What is the best everbearing strawberry variety?
We suggest 'Albion', a variety that produces berries of a decent size. 'Albion' is a day-neutral (everbearing) cultivar similar to 'Diamante' and 'Seascape' and is resistant to wilt and crown rot, and is relatively resistant to anthracnose crown rot. It is an improvement on other day-neutrals in that it is earlier to fruit, has fewer unusable berries, and better flavour and colour. Best variety for planting in pots.
I have a Brazilian Begonia that has white spots on it. What is this?
Without a sample it is hard to be sure, but consideration should be given to:
1. Powdery mildew: A fungal disease often caused by poor air circulation and high humidity. Try not to wet the foliage when watering. An old remedy is to use 2 tbsp baking soda to 1 gallon of water applied as a spray. A mixture of one part milk to 10 parts water has also been effective.
2. Botrytis blight: The spots are usually tan coloured. Established plants rot at the crown. Maintain low humidity, space plants, remove dead and dying leaves and crowns.
I have seen heavenly bamboos (Nandina domestica) with beautiful berries but mine have none. Also, my heavenly bamboo gets flowers but never berries. Why?
In mid spring, nandinas bear large numbers of pink buds opening to white flowers. If the shrubs are pruned either just before, during or after flowering, there will not be fruit. Nandinas are self-fertile so they donít need another plant nearby to produce fruit. Good care is essential. They like moist, fertile soil and will fruit in sun or shade. Prune out the oldest canes completely every year or prune back oldest canes to various lengths to create a dense bushy growth.
**Some cultivars do not produce berries and other cultivars produce flowers but no fruit. Nandina berries can be poisonous to many hungry birds.
They contain low levels of toxic hydrogen cyanide. Perhaps pruning to avoid berries is a good idea.
Now, some nandinas are being purposely bred to produce little or no fruit. Such varieties are ëFirepowerí, ëGulfstreamí, ëNanaí, ëWoods Dwarfí, ëSienna Sunriseí to mention a few.
Nandinas can also become invasive in some areas from the spread of seeds.
I have a Japanese Maple that still has dead leaves on it. I have seen this on some oaks as well. Why havenít the leaves fallen off?
This is called marcescence. Normally deciduous trees shed their summer coats however, some are more reluctant. These trees include oaks, beeches and some maples. The cells at the interface between twig and end of leaf stem release enzymes that ëunglueí the leaf in the fall. But for some reason, this doesnít happen to some trees.
There is speculation as to why this happens. Some say it deters browsing animals because the dried leaves conceal buds and dead leaves protect the twigs.
Others suggest that trees hold onto their leaves so the dead leaves fall in spring offering nutrient recycling when the tree starts to grow.
This marcescence occurs most often on younger trees and most often on lower branches. So go out and have a look.
Last summer I had a lot of the top flowers drop off my scarlet runner beans. Why?
This sounds like heat and/or drought stress.
Under normal growing conditions evaporation of water from leaves draws water upward from the roots the vascular system in the plant called transpiration.
Under drought stress, plants have to close their leaf pores to keep in moisture and closing of leaf pores shuts down photosynthesis. They canít get nutrients. Beans will drop their flowers and have distorted or unfilled pods as a result of stress. This mainly happens when temperatures rise to 27C or higher.
Pod failure can be caused by several factors:
Lack of moisture.
Poor soil conditions. Acid soils below pH 6.5, lack of nutrients or organic matter.
Low numbers of pollinating beesÖ.to mention a few.
Resilient Gardens 2016 by Linda Gilkeson
Is it too late to wash my mason bees? (This is mid-February)
You can still wash your mason bees if they have been stored in a cool place and have not started to come to life. Ideally, they should be done between October and December. Mason bees are well adapted to cold weather.
By harvesting and cleaning the mason bee cocoons you are helping to ensure the health of future generations of bees.
Mites multiply rapidly and infest the eggs. Washing the cocoons in a sieve in tepid water removing areas of rust colored dust-like material is removing the mite source.
The cocoons will normally sink if they are infected and the viable ones will float.
Place the cocoons in a 5% solution of bleach and swish for 3-5 minutes. Pat dry on a paper towel and allow to air dry for a day. Place the cleaned cocoons in a breathable sealed container or envelope and store in the refrigerator.
Some people like to buy tiny wooden boxes (2î size) at a dollar store, drill a small hole and leave these boxes near the bee home. When the buds of the early trees and shrubs appear to be breaking dormancy, you can place the cocoons near your mason bee house.
Other Interesting stuff: Male mason bees emerge first and the females later. The back tunnel area of the mason bee home stores the female bees while the front openings usually contain the males. The males emerge first, mate and die. Every female mason bee is fertile and makes her own nest. They do not produce honey or beeswax. They are an amazing pollinator. Mason bees rarely sting, they have no barbs and if they do sting, it is very mild.
More interesting stuff: Mason bees tend to be active for only about 2 months of the year and then they settle down to set the cocoons. This is a time when the cocoons become vulnerable to parasitic wasps. Many people recommend covering the front of the bee home with fine fabric to prevent invaders or taking down the homes and storing them away in a garage or cool place in July.
I bought a mutant yam (or sweet potato)! The flesh is white on one side and orange on the other. What is going on?
It is not clear what has happened but mutants and sports happen all the time and of course there are white yams, orange and purple ones and may have crossed. It is likely a sport (like a variegated leaf on a plant that has otherwise all green leaves.
So what is the difference between a sweet potato and a yam?
The sweet orange-colored root vegetable you know as íyamí is actually a sweet potato from the same morning glory family (Convolvulaceae). True yams generally come from Africa and Asia and are related to lilies. True yams are starchier and drier than the varieties we find at our local stores and are tough to find.
The sweet potato produces more pounds of food per acre than any other cultivated plant. They are more nourishing than white potatoes and the universal food of tropical America.
The origin of the sweet potato is thought to be either Central or South America and was domesticated at least 5000 years ago with some dating back to 8000 BC.
Linda Gilkeson via email
How and when do I prune a Goldflame spirea?
Goldflame spirea (Spiraea japonica†'Goldflame') is noted for its good heat tolerance and foliage which changes colour from rusty pink in early spring to bright green in summer. The pink flowers bloom from new wood, so most of the pruning occurs in late winter and early spring. Remove old blooms right after they brown in the summer by sliding pruning shears down the flowering stem to the connecting branch or a new leaf. Deadheading like this will stimulate a new flush of flowers.
This spirea is very thick and shrubby. Inspecting it in late winter when dormant lets you see branches that need cutting. First cut back any dead or broken branches to a connecting branch or bud. Next cut away branches growing inward. This will open up the centre of the plant to better air circulation. Spirea can be prone to powdery mildew which affects many plants especially when crowded. After opening up the centre stand back and decide how high and wide it should be, and what shape (natural or rounded). Cut to a connecting branch, main trunk, or a leaf or bud. Spirea are responsive to renovation pruning so every 3 years you can cut the entire plant back to a few inches above ground. This will stimulate new green growth and bloom and keep the plant healthy.
Spirea are in the rose family so susceptible to leaf spot, fire blight, powdery mildew, root rot, scale, and leaf roller.
Last summer the temperatures were warm early and my lettuces bolted. Which kinds of lettuce do better in warmer weather?
There are 5 basic forms of lettuce: babyleaf, romaine, crisphead, looseleaf and iceberg. Mesclun varieties are a blend of lettuces and herbs. Darker leaved lettuces are more nutritious as are the outer leaves.
Local seed producers have been growing lettuces for warmer temperatures. Start in spring with ones that like cooler conditions, then later sow short rows successively with quick growing types suitable for late spring/early summer. Then in late summer sow the cooler weather types. The shorter the growth period, the better for warm weather varieties (see suggested varieties below). Slower bolting varieties will resist becoming bitter.
Plant warm weather lettuces in part shade, keep well watered, and cover with floating row cover which can extend your harvest up to 3 weeks.
Pacific Northwest Company (Vernon)
Grand Rapids 45-50 days
Royal Red 45-55 days
Salad Bowl 45-55 days
Full Circle Seeds (Sooke)
All Weather Lettuce Blend
All Weather Lettuce Blend
West Coast Seeds (Ladner)
Drunken Woman 55 days
Amish Deer Tongue 31 days
Anuenue 50 days
Organic 55 days
Buttercrunch 67 days
Freckles 55-70 days
Tropicana 70 days
Can I buy a Christmas tree and plant it in my garden?
Most Christmas trees are conifers (e.g., pine, spruce, fir) that have been cut specifically for the Christmas season. A living Christmas tree that retains the root system (either planted in a pot or burlap sacking around roots) can be planted in your garden later. This is a great, environmentally-friendly idea but requires some forethought and planning.
The first things to consider is the type and size of tree you want. Buying a living tree will give you more options than buying a cut tree. You want to be mindful that the root ball on a living tree will add to its weight and this is important as you will be moving it around. Some fir trees that are pleasing as Christmas trees include the Fraser fir (Abies fraserii), Rocky Mountain fir (Abies lasiocarpa), and the white fir (Abies concolor). The Norway spruce (Picea abies), Blue spruce (Picea pungens Glauca group), Oriental spruce (Picea orientalis) and Alberta spruce (Picea glauca) are also favorites. You might consider keeping the tree in a pot so it can be brought into the house each year and repot it as it grows. While conifers may live for a few years in a container, they are not naturally suited to pot cultivation. A conifer would be much happier planted in your garden and the location must be carefully considered. Most conifers prefer a sheltered location with full sun and good drainage. It must also be kept in mind that conifers can grow to be VERY large trees, sometimes reaching 15-20 m (50-65 feet) in 20 years and even larger after that! Even the Korean fir (Abies koreana), one of the smallest of the conifers, can reach 4 m (13 feet) in 20 years and 10m (33 feet) over time. Perhaps a dwarf conifer like the dwarf Serbian spruce (Picea omorika nana) would work for you?
Once you have selected the tree that is the right type and size for your situation, it will require some special attention while in the house decorated for the Christmas season. Because the conditions inside the house can be quite drying, try to position the living tree in a cool location away from heat sources. Check that the soil remains moist but not waterlogged. Keep the tree in the house for only 10-12 days as new tender growth of roots will begin if left too long in the house, making the roots vulnerable when moved outside. Move the tree to the harsher outside climate gradually, if you can. For example, if the weather is very cold, move the tree to a protected area near the house for a few days before planting it in the ground. Don't wait until spring to plant the tree.
To plant the tree, dig a hole twice as wide but not deeper than the root ball. If the ground is likely to be frozen just after Christmas, prepare the hole in the late fall. Remove the burlap sacking (or remove the tree from the pot), loosen outside roots and cut off any damaged roots. Place the root ball in the hole with the top of the ball even with the soil. Fill the hole in stages with loosened soil that has NOT been amended with organic matter. Gently tamp down each layer of soil to remove air pockets. You can add 5 - 7 cm (2-3 inches) of mulch like leaf mulch on top of the root ball, if you wish. Water thoroughly. Do not fertilize the tree now. Make sure your tree receives water regularly throughout the winter and increase watering during the growing season.
Sustainable Gardening (1999), Oregon State University, page 187.
Why is my Christmas cactus wilting or not blooming?
The Christmas cactus (Schlumbergera) naturally lives in jungle-type woodlands attached to trees and, unlike the desert-dwelling cacti, does not do well in full sun. Their preferred location is well-lit, semi-shade, with a humid atmosphere. If the plant gets too hot or is situated in a sunny location, the stems can shrivel or wilt. Drying out or being over-watered can cause root deterioration resulting in stem wilting. Remove the plant from the pot to check the root development. If there is little or no sign of new growth, gently remove the soil and replace the soil with a standard cactus compost. Christmas cacti like to be snug in a pot and may not do well if the pot is too big. To form flowers, the Christmas cactus needs short days and low temperatures. If the plant is not blooming, place it in a cool location (10-13∞C or 50 - 55∞F) with more than 12 hours of darkness each day until the flower buds form. Once the buds have formed, increase the temperature up to 18-20∞C (65-69∞F) and water regularly. After the Christmas cactus has flowered, a rest period (approximately January-March) is required. Move it to a cooler room with temperatures12-15∞C (55-59∞F) and only water occasionally but don't let it dry our completely. From April through September, increase watering and maintain a temperature of 18-20∞C (65-69∞F), if possible. Christmas cacti like to go outside in the summer months but be sure to keep them in a shady location and protected from slugs.
Sustainable Gardening (1999), Oregon State University, page 27.
How do I care for my poinsettia plant?
Poinsettia (Euphorbia pulcherrima) is a tropical plant so they are tender in our climate. After purchase at this time of year keep the plant in bright filtered sunlight indoors, water sparingly but thoroughly, and mist daily. They don't like being in drafts or near radiators. To keep the plant blooming for longer put the plant in a cooler place at night or keep the heat down overnight.
You can keep the plant through the year to aim for fresh growth and coloured bracts next year. In spring repot the plant if it has grown too large. The pot can be sunk in a well drained slightly shaded spot outdoors. It may need to be watered more frequently than the other garden plants as the plants are shallow rooted. Fertilize every 2 weeks with houseplant fertilizer. In late August prune all shoots to 4" leaving 1-3 leaves on each shoot. Bring the plant indoors in late September to avoid it getting chilled. For the poinsettia to colour up put it in a completely dark cool place from 5:00 pm to 8:00 am. daily from November. If the temperature is above 70 degrees F. flowering will be delayed. Continue to fertilize every 2 weeks with houseplant fertilizer as per product recommendations. Bract coloring is triggered by short winter day length with 12 hours light and 12 hours dark. A constant temperature of 18 degrees C. is ideal for night temperature. Colour in the bracts should be showing from mid. Dec. when you can display your plant in a bright draft free cool spot.
Gray mold can affect poinsettias when overwatered.
When and how do I prune fuschia plants?
Fuschia are included in the group of plants that bloom after mid summer. They produce flowers on the current year's growth, on new wood. Spring is the time to do the heavy pruning on these plants so that all danger of frost has passed and new buds aren't harmed. Pruning will give the plant its correct framework. Plants should be cut down to a low framework to just above where new shoots are budding. After this, weak, thin and spindly branches should be completely removed. Cut back remaining branches by at least two thirds. Old established plants are cut back the same every year and will grow to their former size. Low bush types can be pruned this way and tall varieties shaped into pillars or large spreading shrubs, or they can be trained flat or espaliered against a wall, fence, or trellis.
Spring is not the only time to prune. As growth continues through the season you can pinch back new shoots up to a month before the blooming season. This will make bushy and symmetrical plants with more plentiful blooms. For techniques of pruning standard fuschia refer to "pruning fuschia", rhs.org.uk.
Encyclopedia of Pruning & Training
Should Ceanothus be pruning this time of the year?
Ceanothus usually bloom late spring and into summer. This year, many plants are sending out another flush of color. In my yard, the Choysia ternate (Mexican Mock Orange) and some Rhododendrons are blooming again. The article cited below postulates that drought conditions in the summer cause the plant to break dormancy once the drought it over and the plant again starts to manufacture sugars and starches.
Does BC have the lily leaf beetle?
I could find no instances of the scarlet lily leaf beetle being reported on the island or in BC. I also checked with Linda Gilkeson who had been shown one by a Washington State master gardener, so it will only be a short time before it becomes another pest for us to control as well. Since it is not yet an issue, I won't go over control techniques at this time. The source cited below provides clear and concise information should you want to read up on the critter.
personal communication, Linda Gilkeson, October 11, 2016
What is the slug-like insect eating the leaves on my cherry tree?
The slug-like insect is the pear sawfly or pearslug (Caliroa cerasi). The adults emerge from cocoons in late June into early July, with a smaller second generation towards the end of August into September. The adults are small, dark wasp-like insects. The larvae, are the small slug-like larvae and are black to olive-green in color and grow to be about 1/2 inch long. They chew holes on the leaves between the leaf veins. When fully grown, they drop to the soil and spin cocoons to overwinter in the soil. The damage is not usually harmful to fruit trees unless the numbers are high. They attack pear, cherry, plum, hawthorn and cotoneaster. Most wash off easily with water sprays and on pears, this method is as effective as insecticides. Lime Sulphur spray, applied after pears are harvested is also effective. Do not use the spray before harvest, as the Sulphur will damage the skin of the fruit
West Coast Gardening: Natural Insect, Weed and Disease Control.
What should I plant under or near my fruit tree?
It is best to keep the area around and under fruit trees clear of vegetation. You will need space to harvest the fruit and to perform regular pruning. Top dressing with mulch around the drip line of the tree (but not against the trunk itself) is beneficial to the tree and will control weeds, help to cool the roots and help to retain moisture in the soil. It will also permit deep watering with a soaker hose during periods of drought, while the fruit is actively growing. While many sources advocate growing vegetables under the tree, remember that tree roots are close to the top of the soil and will out compete the vegetables for water and nutrients and provide an overabundance of shade. Digging will damage the trees delicate feeder roots, as will the compaction from working in the area.
personal communication, Noah Alexander- arborist( September 2016)
I have a Phormium tenax (New Zealand flax) that is getting too large. Can I prune it back?
Ideally, the plant should be lifted and divided in the spring. To make the task easier, dig out the clump and use a saw to cut it into four pieces. Replant one and share the rest. If you have access to a reciprocating saw, using this to saw it apart makes the task so much easier! This time of the year, remove all dead and damaged leaves to tidy up the plant.
Should I prune my hellebore?
Hellebores are lovely plants that come in a variety of colors and bloom in late winter or early spring. Some varieties may have striking foliage. They really brighten up areas in winter gardens situated in dappled shade! Pruning the old leaves from hellebores can serve a number of purposes and can be done as the new flower buds emerge (in late winter/early spring) or when the new leaves start the emerge (a couple of months after the flowers blooms start). If the old leaves are removed early (as the new buds emerge), your hellebores will be all stem and flower for a while. This gives a very clean, minimalist profile in the garden. You may prefer to retain the old leaves as the new flowers emerge, then snip out the old leaves as the new ones emerge. Exactly when to do the leaf pruning depends somewhat on the conditions where you live and which of the 15 species of these lovely perennials you have chosen. In our region, Christmas is often a good time to think about getting around to this task. Trimming the leaves off early provides the advantage of ensuring the new flowers can be seen and pollinated freely by insects. In addition, when the leaves are removed, there is no place for snails and bad bugs to hide, and mold or other diseases that may be affecting the old leaves are eliminated.
You will also want to prune out dead flower heads when the flower color becomes dull and the seed pods begin to enlarge. Hellebores can bloom for a long time, so don't be too quick to remove the flowers. When you do cut the flowers, they can make a lovely display as cut-flowers in a vase! While hellebores spread via seed very quickly, it may take a very long time before the new plants bloom and the flowers may vary in color. For these reason, pruning the flower heads off before the seeds spread can save you the work of removing the hellebore sprouts from your garden. A better way to propagate most hellebores is through division of large clumps in spring or fall.
How can I remove the buttercups from my lawn?
Buttercups are lovely flowers, right? Some varieties of Ranunculus are highly sought after and gorgeous additions to any garden. However, Ranunculus repens, or creeping buttercup, can become a real problem in your garden or lawn. This perennial weed grows particularly strongly, and roots deeply, in moist soils and can even withstand waterlogging. In areas like ours with mild, wet winters, these buttercups can spread widely in moist, heavy soil through long runners that produce deeply penetrating roots from each leaf node.
When lawns are mowed, you may not see the tell-tale yellow buttercup flower. Creeping buttercups spread via seed as well as runners, so it may be a good thing for the flowers to be absent. However, the runners can still spread invasively and need to be removed.
Without the use of herbicides - Hand pulling may be possible, if small patches of the buttercups have begun to emerge. However, be mindful that any small nodal sections of stems that are severed and scattered will create new little plants. Whatever you do, when removing the buttercups stems and roots, make sure you don't leave any bits lying around. Those little pieces will take root and make your problem worse! Wear protective clothing as the sap is dermatologically toxic.
Another approach is to change the growing conditions to ones less appreciated by the buttercup. Try allowing the lawn to go dormant in the summer to dry out the soil. Buttercups like nutrient poor, compact soil with low pH. So, if you can, lower the acidity of your soil, increase soil drainage, and fertilize.
Once you get the problem under control, vigilantly watch for, and attack at, the first signs of reoccurrence!
Gilkeson, L. (2013). Natural insect, weed & disease control (2nd Ed.)
How do I divide my perennials?
There are a few different techniques for dividing perennials which depend on what type of roots they have.
Root types include: surface roots, taproots, woody roots, underground roots, and offsets.
Surface roots: run on or just below the soil and form new crowns when making contacting the soil or reaching open spaces. Examples: monarda, rudbeckia, creeping sedums, creeping veronica.
Tap roots: divide by slicing down the length of the root with a sharp knife. Look for a piece of the taproot with at least one eye and a few side roots for a division. Examples: oriental poppy, cause on spurge, balloon flowers.
Woody roots: root from stems resting on the ground or buried by accumulating mulch. Cut between the rooted stem and the mother plant. Examples: candytuft, sage.
Underground roots: Japanese anemones, hardy geranium.
Offsets: offsets are small plants that grow at the base of a larger one. Snap the connection between the sections to get a plant with ample roots, and three or more growing points, or eyes. Examples: coreopsis.
Look for signs that a plant needs dividing: centre of the plant has weaker stalks, there are smaller leaves and fewer flowers, or when the plant is crowded.
Divide in cool weather: mid spring or early fall so that roots can grow while the tops aren't scorched or it's too windy. I prefer fall so that I know I'm not stepping on plants that haven't emerged and soil is winter wet. I leave fall bloomers til the spring and spring bloomers til fall. Make sure roots are kept cool and moist while replanting. If divisions dry out you can moisten them in a bucket of water.
Roots usually extend to the drip line of the plant so dig at this line. First dig a trench around the plant and sever roots, then angle your shovel to cut under the plant at several points. Avoid tearing up the roots. With larger clumps you may have to slice right through the middle and then quarter it. Use around one quarter of the original plant as small divisions will grow vigorously and not need dividing again for a few years. Keep only the healthiest sections, usually on the outside. Place the plant in a hole that is as wide as its roots and spread them out.
Replenish soil with organic matter. The volume of compost added back to the soil should be about the same as the plants taken out or more. This will help drainage and air circulation in the roots as well as adding fertility.
How do I prune lavender?
Lavender is a semi shrub which has characteristics of both a shrub and a perennial. The plants should never be cut down close to the ground as perennials are. The centre of lavender plants grow woody after a few seasons so it is important to be ahead of this. Lavender blooms on stems produced the current year so pruning after blooming finishes is correct. Sometimes a second bloom will happen and this growth also needs to be removed by about 1/3. Woody growth will not rejuvenate itself, so make sure there are nodes left above the wood for future growth. Grab a handful of stems at once to speed up the process, then go back and shape the plant. Create a higher centre than the sides so plants will look lush and full when blooming. If lavender is pruned in the fall the plant will respond by wasting energy on new growth which is too tender for winter frost and it will lose vigour or die altogether. All lavenders are pruned using the same techniques. In spring cut away damaged and dead parts as they will not recover. By maintaining good pruning plants will bloom vigorously or many years.
I have three or four young pear fruits at the end of each branch of a three year old pear tree - how much should I thin them?
It's a funny thing but when conditions are ideal, many fruit trees, including pears, set more fruit than is ideal. For this reason, removing some of the excess fruit, or thinning, will result in improved fruit size and quality and will also promote next year's crop. Sometimes, fruit trees will naturally drop some fruit in the early summer. Inexperienced gardeners may wish to wait until after this 'June drop' to thin the remaining fruit and finish thinning by mid-July. Experienced gardeners tend to do their thinning earlier. Always remove malformed fruit as soon as possible so the tree is not expending energy on fruit that will not develop properly. Pear trees can be prone to over-bearing but need less thinning than other types of fruit trees. Thin clusters to two fruits, or even one on a young tree, and retain the largest fruit whenever possible. Typically fruit is thinned by hand, but a pole can be used to tap the clusters on large trees. The pear tree should be pruned every winter to ensure a good cycle of fruiting wood and keep the size of the tree manageable for future thinning and harvesting.
Sustainable Gardening: The Oregon-Washington Master Gardener Handbook, April 2013 (pages 214-15)
When should I stop watering my garlic?
Garlic is a great plant to grow - it takes up little space in the gardens, it is a healthy vegetable that has many culinary and medicinal uses, and it lasts for months after harvesting. It is also fairly easy to grow. Don't plant cloves from the supermarket - the ones available in garden centres will be healthier and more productive. Musica, Purple Softneck, Portuguese Red and Red Russian are just a few of the tried-and-true varieties available.
Garlic is typically planted in the fall (Sept. - Nov.) and mulched for the winter. Mulching helps to provide even moisture for the garlic, moderates soil temperature and inhibits weeds. Once established, garlic requires little watering, though an occasional thorough watering during dry spells in the spring will improve the quality of the yield. Overwatering can lead to poor quality cloves, rot and mold. In June, hardneck varieties send up central seeds (scapes) - these should be removed to keep energy in the bulb and can be eaten in salads or stir-fries. Stop watering 2-3 weeks after cutting the scapes which will be about 2 weeks before it is time to harvest (about mid-July for most varieties). You will know it is time to harvest hard-neck garlic when half to two thirds of the leaves look dry. Soft-neck garlic is ready to harvest when the tops fall over. Loosen the ground around the garlic and lift the bulbs carefully. Air-dry by hanging in bunches or spread them in a single layer on trays. With experience, the garlic gardener will learn when it is the ideal time to stop watering and when to harvest.
L. Gilkeson (2011). Backyard Bounty: The Complete Guide to Year-round Organic Gardening in the Pacific Northwest (p. 237).
West Coast Seeds Gardening Guide 2015.
I would like to grow succulents in my garden. What types will grow in this climate and what kinds of conditions to they need?
Succulents are plants that have the ability to store water in their stems and leaves. This makes them particularly adapted for arid or dry climates. Many succulents are tender and must be grown as houseplants. Others, though, are hardy and can handle our west coast winters (when given excellent drainage and/or shelter) and our dry summers. While there are many hardy succulents, perhaps the most diverse and readily available are from the Crassulaceae family and include Sempervivum and Sedum.
Sempervivum is a genus of about 40 species of evergreen succulent perennials that form mats of plump rosettes often known as hens-and-chicks or houseleeks (from their old name - hauswurz). The name hens-and chicks arises from their method of producing offsets or baby rosettes (or chicks) on stolons around the mother plant (the hen). The rosettes of the Sempervivum come in various shapes, sizes, textures, and colours from near-black, pinks, purples, apricot and every shade of green, making them fascinating additions to your garden. Some are even covered with a web of white hairs and are known as cobweb houseleeks. Star-shaped flowers are borne on upright stems in the summer and may be white, yellow, red or purple. The rosettes of Sempervivium are monocarpic, meaning that they flower once and die, but the offset rosettes take their place.
The name Sempervivum means ‘ever/always living’ and aptly describes these tough plants that reproduce easily and require minimal care. They do well in a garden border or in containers, troughs, or rock gardens. They must have well-drained soil (e.g., cactus mix or incorporate up to 50 percent sharp sand, grit or perlite into garden soil) as they may rot if waterlogged. Most species prefer dry, sunny locations. Jovibara is a genus of succulents with characteristics similar to Sempervivum, so look for them too.
Sedum, also known as stonecrop, is a genus of succulents that contains over 400 species and is even more varied than Sempervivum in colours, sizes and shapes. Like Sempervivum, many Sedums are hardy in our climate. They are shallow-rooted so do not require much soil to thrive and divide easily to spread around the garden. They can be used to fill in between other plantings and they adapt to spots that are too hot or awkward to accommodate most other plants. Like Sempervivum, Sedum will also do well in garden beds, containers, troughs, or rock gardens and prefer well-drained soils and sunny locations. Some vigorous species will tolerate light shade.
Other succulents such as Delosperma, commonly known as Ice Plant, flourish in dry, sunny locations as well, and produce lovely daisy-shaped flowers in summer. Many other succulents are available in garden centres during the summer but may need to be brought indoors in the winter (e.g., Echeverias) so ensure the plants you choose are hardy succulents if you wish to leave them in the garden all year.
Fingerut, J. & Murfitt, R. (1999). Creating and planting garden troughs. Wayne, PA: B.B. Mackey Books.
What kinds of raspberries do well in our climate?
There are many different raspberry cultivars that grow well in our west coast climate. Raspberry production is one of the agricultural industries of British Columbia, including Vancouver Island. Raspberries come in four colours: red, yellow, purple and black and differ in size from small to very large. Some of the red raspberry varieties that ripen in early to mid-summer (floricanes) include Cascade Dawn (medium-large), Chemainus (medium), Malahat (medium-large), Meeker (medium), Saanich (medium), Tulameen (large-very large), Williamette (medium-large). Other varieties such as Anne (yellow, large), Autumn Bliss (red, large), Heritage (red, medium), Jewel (black, medium-large), and Royalty (purple-large to very large) ripen in the fall (primocanes or ever-bearing).
While all raspberry plants are perennial, the canes are biennial. For most types of raspberries, in the first year the canes only produce leaves. The fruit is produced in June/July of the following year (floricanes). The cane then dies and must be removed after fruiting. New canes will be growing to take their place. The fall-bearing varieties produce flowers and fruit during their first year after planting (primocanes) and can be left to fruit again the following year in June/July (hence the name ever-bearing). These canes too will need to be removed after their second fruiting and new canes will be taking their place.
So, raspberry cultivars differ in fruit characteristics such as colour, size, and taste as well as when they bear fruit and tolerance to pests. It is important to know the differences between the cultivars when selecting the certified disease-free raspberry stock variety for your site and purpose.
Washington State University/Oregon State University (April 2013). Sustainable Gardening: The Oregon-Washington Master Gardener Handbook (p. 299-234).
March Clinic Questions
Why aren’t my lettuce and spinach seeds germinating?
There are a couple of possible reasons for this: the seeds may not be viable, the temperature may be too high or too low, or the soil may be too wet or not wet enough.
Viability - usual seed life is three years. There is a way to test seed viability. A few weeks before planting time, count out a few seeds and place them on a paper towel. Label the seeds and dampen the towel. Place a plastic bag around them and almost close the bag. If three quarters of the seeds sprout they are 75 percent viable, which is the average. They should sprout in seven to 15 days. If fewer sprout it is time to buy a new package.
Temperature - lettuce and spinach seeds need a soil temperature of 50-75 degrees F or 10-22 degrees C. The optimal temperature is 70 F or 21 C. If soil temperature is not ideal you can pre-sprout seeds in a cool area indoors then plant the seedlings outdoors. Water the seed tray from the bottom by placing it in a pan or sink in water for a couple of hours. Always harden off seedlings by reducing water and put outside during the day for a few days and bring them in at night.
Moisture - if you are direct sowing seeds outside plant five millimeters to one centimeter deep (1/4-1/3”) and keep the soil evenly moist. Good air circulation is important and don’t cover seeds with plastic. You may need to water using a fine spray two or three times daily in warm or windy weather.
Lettuce and spinach do best in cooler weather and plants will bolt quickly in summer. You can protect them from heat by placing plastic trays upside down over the plants as they sprout and are small.
Backyard Bounty, The Complete Guide to Year Round Gardening in the Pacific Northwest by Linda Gilkeson
Can I grow ginger and horseradish in my garden?
Yes, both of these plants can be grown.
Western Ginger, or asarum caudatum, is a plant native to B.C. It is an evergreen perennial with extensive rhizomes, trailing stems which root freely, often forming large mats. The leaves are heart to kidney shaped, shiny, long stalked, with two at each node, four-10 cm long to 15 cm wide. The leaf stalks and veins are finely hairy. Flowers are purplish brown to greenish yellow, solitary, bell shaped with three long points, often concealed by leaves. The fruits are fleshy capsules and seeds have a fleshy appendage. The whole plant has a strong smell of lemon-ginger when crushed. Several First Nations groups traditionally used the plants for tea, poultices, and other medicinal purposes. It grows on rich bottomlands in moist shaded forest. Grow in open to deep shade. It is adaptable to dry or moist conditions. Water occasionally although wild ginger is drought resistant when established. The plants are slow to spread and are deer resistant.
Horseradish, or amoracia rusticana,is a spicy root used to flavour beef when it is grated fresh or pickled. It grows from bare root sections as it sets few viable seeds, is hardy to zone three and grows to about five feet tall. The main root is harvested when the leaves die down in fall. Replant one or two of the side roots for next year. Dig up each plant when harvesting as they will spread vigorously if left in the ground. Plant is full sun to part shade in spring or fall in any soil that isn’t waterlogged. Loosen soil to a depth of 12 inches and dig in a shovelfull of well rotted compost. Plant each segment at a 45 degree angle with the narrower end pointing down. Keep the top of the segment two inches below the soil surface. Water and mulch in warm weather.
January Clinic Questions:
I would like to grow an indoor herb garden. What kinds of herbs can I grow indoors? What kinds of conditions do herbs need?
An indoor herb garden is a great way to keep your hand in gardening all year and provide you with fresh herbs at home for a fraction of the cost of buying them at the grocery store. This is a great gardening alternative for apartment or condo dwellers too. An indoor herb garden takes no more time and effort than any houseplant. With just a little planning, you can grow a luscious array of tasty treats to be added to soups and salads, and used as garnish.
The first thing to consider is the lighting available in your home. Most herbs need as much light as they can get to grow successfully. A sunny spot that that gets four to eight hours of sunlight is sufficient. Windows that face south, southwest, east or west are best though south facing windows may be too hot in the summer and require some shade. North facing windows do not get enough light for growing herbs. As the light quality drops quickly away from the window, you’ll want to place the plants fairly close to the light source. Remember to rotate your plants toward the light so all sides flourish and the plant does not lean to one side. If you do not have a window with sufficient light, you can use fluorescent grow lights, placing them just above the plants (four to six inches) and leaving the lights on for about eight hours. Full spectrum grow lights come in different sizes and prices vary.
Herbs are like people in that they prefer indoor temperatures between 18-21 degrees C. (or 65-70 degrees F.). At night, the temperature close to a window may drop to 12 C. (or 55 F.) but most herbs don’t mind as long as the leaves don’t touch the window glass (brrrr). Some herbs, like basil, do not like the cold and prefer to be warm throughout the day (about 21 C. or 70 F.). Keep your herb garden away from the drafts caused by open windows or doors.
Now, how to choose the herbs for your indoor garden. This will partially depend on your taste (literally!) and the type of lighting available. There are many herbs, leafy greens, lettuces, edible flowers and some peppers that will thrive indoors. Some plants that love and need a VERY sunny location are: thyme, oregano, sage, marjoram, chili peppers, basil, parsley, cress and calendula. Others prefer a slightly shadier spot: mint, chives, lettuce, spinach, parsley, thyme, mizuna, and miner’s lettuce. You might want to start with just two or three of your favorites (e.g. oregano, chives and mint or rosemary and thyme). If planting many different types of herbs together, you’ll want to choose ones that like similar conditions (e.g. Mediterranean herbs such as oregano, marjoram, thyme particularly love sun and good drainage; lettuces grow well together). Some herbs, like the mints, tend to take over an area and should be grown in a pot by themselves. Mint may require frequent repotting. Rosemary, bay, and sage can be left in a container for several years before repotting.
Next, you will need to select containers for your herbs. While any pot at least six inches deep will do, glazed or plastic pots do not dry out as quickly as other types of pots. The deeper the pots, the more room there is for root growth. Window boxes are ideal. Make sure the container has drainage holes and set the pot on a saucer, liner or drain pan. You can even set the pot on some pebbles in the saucer. This serves two purposes: first, it provides humidity for the herbs that may be warranted in dry indoor air, and second, it reduces the likelihood that the pot (and roots of the herbs) will be sitting in water. Herbs don’t like to get their feet wet!
You will want to use a good quality potting mix in which to grow your herbs. The nutrients in the soil will feed the plants and fertilizing will be kept to a minimum. Herbs do not require much feeding from fertilizers in the winter but occasional feeding (once per month) with a food-safe natural product may be warranted in the growing season. If you want to grow your herbs from seed, you can plant the seeds in some starter mix (lighter and airier that potting soil) in smaller containers like peat pots and transplant them into your larger herb containers when they have at least two sets of true leaves (about eight centimeters tall). Or you can purchase starter plants or seedlings from nurseries or garden centres. These are usually available from late spring until the fall. Put some soil in the bottom of your container, place the plant gently on top of the soil and fill with potting mix, pressing the soil firmly around the plant. Make sure the crown (where the roots meet the stem) is level with the top of the soil (i.e. not buried). Leave some room at the top of the pot (about one inch) to allow for watering. Try putting three plants in a window box, leaving some space between them so they have room to grow. While you’ll want to keep your herbs watered regularly, they don’t want too much water and never want to stand in it. Too much water will cause them to wilt and lose their flavour. Check them daily and water when the top of the soil feels dry. Never let them dry out completely. Remember that different plants may have different watering schedules and this may change with the seasons.
Herbs are not bothered much by pests but if you see some bugs chewing on the leaves, mix up a mild solution of soapy water and spray well.
In very little time, you will have herbs growing, though they may appear more stretched out and spindly than those grown outside and will not be quite as productive. You can still harvest the leaves regularly but never remove more than one third of the plant. This might even encourage the plant to become more compact. If you are aiming for edible flowers (e.g., violas, calendula, pansies), be sure not to remove the flower buds. You can harvest fresh herbs by pinching back the tips of the stems to eat them fresh or cut the stems and air-dry them in bunches. You can move your containers outside in the summer and bring them in again before the first frost in the fall. Remember to check for pests when you bring them in. Better yet, keep your herb garden indoors all year. Happy herbing!
The Herb Gardener: http://theherbgardener.blogspot.ca/2008/06/tips-for-growing-herbs-indoors.html
Canadian Gardening: http://www.canadiangardening.com/gardens/indoor-gardening/how-to-grow-windowsill-edibles/a/29994/2
Royal Horticultural Society: https://www.rhs.org.uk/advice/profile?pid=142
Montreal Botantic Garden: http://espacepourlavie.ca/en/growing-herbs-indoors
Growing Herbs by Y. Rees & R. Titterington, Whitecaps books, 1994.
What should I be doing in my garden during the winter months (Nov. – Feb.)? What can I do to get ready for spring?
Well, what you do in your garden during the winter months really depends on how active you wish to be. For those living near coastal B.C., there are a number of gardening activities that can be pursued throughout the year.
Many edible plants such as vegetables can be planted in the summer for fall and winter harvesting (i.e. winter gardening). These include arugula, broad beans, calendula, chervil, corn salad, lettuces, mescluns, mustards, pac choi, scallions and turnips to name just a few. Other plants can be kept in the ground over winter (i.e. overwintered) for harvesting in the spring and summer. These include certain varieties of garlic, onion, cauliflower and broccoli. They need this extra time to fully develop and do not require protection during the winter. In early spring, they will start to grow quickly and you can harvest them as you are planting your spring crops. You can also plant bulbs like tulips in late fall, if you have not done so already.
Another activity that can be carried out, if you have not already done so, is cleaning up and preparing your garden for spring. In the late fall, there are likely to be fallen leaves and woody debris that can be removed. This is particularly important if you have a pond with fish as the leaf decay releases methane gas into the water which can be fatal to fish. You will also want to cut back herbaceous perennials and pull out annuals or other debris to prevent rot. Many communities pick up kitchen and garden waste or have composting centres. Some communities also have composted materials available for use by area residents – check out your local municipal website. You may also wish to raise your containers onto pot feet (or little blocks of wood) to prevent water-logging.
You can also take this opportunity to prune out diseased, dying or dead branches from shrubs and trees. When no leaves are present, it is easier to see where these areas are and the plants are dormant at this time. You may also wish to remove any odd looking branches or prune to enhance the shape of the shrub or tree.
Another great later fall and winter activity is to enhance your garden soil by applying mulch to your garden. Organic mulches can contain compost (commercial or homemade), composted sawdust, chopped or composted leaves. Two to three inches of mulch can be applied but be careful to avoid the crown (where the stem meets the roots) of perennial plants, just bringing the mulch up to the edge of the crown.
You may also wish to set out slug traps by filling an empty tuna fish or cat food can with beer (even the non-alcoholic variety will attract slugs) placing it in a shady spot with the rim of the can at ground level. Empty the can every few days and refill. Be sure you are not also catching creatures that are beneficial to your garden.
Winter is also a great time to walk through your own garden or local botanical gardens to view the variety of plants with winter interest. Interest in winter may come from flowers, berries, coloured stems or foliage. Hellebores and some varieties of clematis bloom over the winter months. Other plants like mahonia and hamamelis (Witch hazel) bloom over the winter months in bright oranges or yellows. Some varieties of cornus (dogwood) have spectacular winter bark or fruit. Many shrubs like nandina have a lovely display or berries over the winter months. By January, some of the early bulbs like galanthus are beginning to bloom. There is never a dull moment in the coastal garden!
Another way to be working on your garden during the winter months is to check out seed catalogues and lists and make some choice selections for spring planting. While seed catalogues are now available to leaf through (pardon the pun), many plant lists are also available via the internet with easy access to information on each plant with direct links. How easy does that make gardening? Happy winter gardening!
Canadian Wildlife Federation: http://cwf-fcf.org/en/resources/gardening/gardening/putting-your-garden-to-bed_resource.html
Royal Horticultural Society: https://www.rhs.org.uk/advice/in-month
West Coast Seeds: https://www.westcoastseeds.com/
Canadian Gardening’s Water Garden by J. Davis, Penguin Studio, 1997.
Where is the best place to buy soil?
Before you buy soil by either picking it up yourself or having it delivered, have a good look at what you are buying. Good quality soil is called loam, and is a mix of roughly equal proportions of sand, silt, and clay. It should have good structure and be well drained. All soils benefit from the addition of organic matter such as well rotted compost.
Look out for things such as a high stone content, thick fibrous roots, weeds, and contaminants such as brick or glass. Ask the supplier where it is from and whether it has been tested and what are the results. Check for evidence of invasive plants such as Japanese knotweed, horsetail, couch grass, and weed roots and shoots. Weed roots are often white and fleshy.
Here is a list of local suppliers:
MacNutt Enterprises Tri Landscape Supply Michell Excavating Integrity Sales and Distribution Victoria Landscape Gravel Mart Peninsula Landscape Supply Gardenworks Blenkinsop location
Sources: Washington State University, www.cru.cahe.wsu.edu Royal Horticulture Society, www.rhs.org.uk
When do you take scions for grafting?
Grafting and budding are used as the principle methods of propagating in certain plants such as fruit trees. They are techniques used to combine one plant with another to encourage growth as a unified plant, one that is identical to the parent plant.
Factors affecting successful grafting or budding are: temperature, time of year, age of the plant parts, scion orientation, and care of grafted plants, soil moisture, and contact of stock and scion.
According to Ross Penhallegon, a horticulturist with the Oregon State University Extension service, peach, nectarines, cherry, and prune wood is best collected in late January. Apple, Asian pear and pear wood should be collected in early February. Scion wood should be cut from the whip-like growth found in the tops of superior quality trees. One year old wood is preferable to older wood and should be of average vigor and well hardened. Wood grown in sunlight is better than that grown in shade. Scion wood can range from 8 to 18”, about the thickness of a pencil, and be free of insects, diseases, and frost injury. Begin grafting whenever weather conditions cause sap to rise freely, and the buds at the top of the tree to swell.
Sources: “Grafting Ornamental Plants and Fruit Trees”, Royal Horticulture Society, www.rhs.org.uk Oregon State University Extension Services, oregonstate.edu, Carol Savon, “Propagation of Plants by Grafting and Budding”, “It’s time to gather scion wood for grafting”
What is a good book about garden design?
The Victoria Master Gardener’s Association (VMGA) Landscape Design Group has some excellent resources listed on their web page. One of the most interesting (in this writer’s opinion) is the book “Plant Driven Design: Creating Gardens That Honor Plants, Place, Spirit” by Lauren and Scott Ogden. The authors write that we don’t have to know all the tenants of design to create an interesting garden. In fact, they say most of the plans taught in landscape architecture programs are formulaic and gardens end up looking like a home improvement project. The Ogdens think that by making plants, their character, structure, individuality, and seasonality the focus of the garden returns gardening to being a relationship between plants and people a happy one. They suggest beginning by observing nature, how plants grow in the wild, where they look their best with other plants. They believe gardening is about curiosity and change, that a garden that is perfect all the time is boring. We want to go out the door and see something different every week. It is human nature to want change. If everything was the same we wouldn’t see it. Unpredictability and imperfection is part of nature. Style is less important that having plants we really enjoy.
Sources: VGMA website, Landscape Design Group, “Plant Driven Design: Creating Gardens That Honor Plants, Place, Spirit” by Lauren and Scott Ogden, Timber Press, 2008
October Clinic Questions:
Can I plant an evergreen hedge in the fall and what kinds of things should I do to prepare the area.
Fall is a good time to plant as the soil is not inundated with water and it isn’t yet cold with frost making it easy to dig. Plants are going into dormancy at this time of year so by getting them in the ground now, they will be in place for their roots to grow the following spring.
Proper preparation when planting your evergreen hedge gets plants off to a good start. Decide on the species you are going to use and investigate the mature width and height and the recommended spacing. Ensure the planting site has adequate drainage and receives enough sunlight for growth requirements.
Prepare the area where the plants will be planted by digging a trench. Soak the planting holes with water and watch to see how long it takes to drain. If it doesn’t there is a problem. You can fix it by either creating a raised bed, installing a drainage pipe, installing a drainage ditch or if it isn’t severe amend with organic matter at the bottom of the dug trench.
Organically rich soil is preferable to help maintain moisture. Supplementing the existing soil with triple mix, compost and or manure will only improve the soils water retention. If you are adding bonemeal or fertilizer make sure to mix all amendments thoroughly with existing soil. Depending on the type and size of plant you have chosen, space the plants accordingly and replace soil around plants tamping down to ensure the plants don’t tip over.
Mulch is an excellent method of adding nutrients to the soil, slowly over time. It also acts as an insulator, maintaining a cool soil temperature, reducing evaporation from the soil’s surface as well as keeping weeds at bay. Ensure the plants are well watered during a dry spell. Top dress with mulch annually.
Royal Horticultural Society
Why does winter squash taste better if left on the vine till late fall?
Of course you can harvest any time they’ve reached mature size but squash develop more sweetness if left on the vine till the leaves start dying back in the fall.
Winter squash become sweeter after a hard frost or two but they should be harvested and cured if the temperature drops below -5c. Most winter squash become sweeter after a couple of months of storage and can be kept up to six months if stored properly.
Over time, in storage, some of the flesh’s complex starch (dry matter) breaks down into simple sugars and water. The 4 VMGA MEMBER PHOTOSresult is squash with improved flavour - a sweeter and pleasantly moist taste. There is an optimal storage period, which differs for each type of squash; after that the squash may appear to be storing well but usually the flavour will decline.
September Clinic Questions:
I have some gray, powdery substance in my vegetable garden (on the foliage and stems of my zucchini, squash, and pumpkins). What is this, is it harmful and what can I do about it?
Given your description of the substance and the time of year, I think your vegetables are being affected by a fungus called powdery mildew. It appears as a white or light gray powdery or furry-textured coating on plants in the late summer and fall. Old leaves are more susceptible than new growth and maintaining vigorous growth helps keep the fungus away.
There are different species of powdery mildews that attack different host plants. Members of the squash and cucumber family are particularly susceptible but other edibles can be affected too such as apples, black currants, gooseberries, grapes, rosemary, and peas. Powdery mildew can also affect ornamental plants such as delphiniums, phlox, rhododendrons, azaleas, and roses.
Powdery mildew typically affects the stems and foliage of plants but sometimes you can also see it on the fruit and flowers. The fungus is present in many places in the garden and can overwinter on plants or in plant debris. The spores of the fungus are spread by wind, rain, insects, or even on the feet of birds. When the right strain of powdery mildew finds the right host plant, the fungus rapidly attacks the surface of the leaves, taking nutrients from the leaf while forming the powdery substance on the leaf.
On vegetables, the fungus typically only affects the leaves and stems but loss of leaves can affect how many squash or cucumbers are produced. Some people recommend removing the affected leaves but others note that the spores have already spread by the time we notice the powdery substance. By not removing the leaves, the plant is likely to continue to get some benefits from photosynthesis. When the affected leaves turn brown and dry up, they can be composted. Just pick the vegetables when they are mature and wash them.
If you notice the powdery mildew early, there’s a few things to try to keep its growth in check. Powdery mildew spores cannot germinate when there is water on the leaves so you can rinse off all the leaves (on both sides) with water at mid-day so the leaves have time to dry before nightfall. Do this several times per week. Another idea was discovered by Canadian researchers: a mixture of milk (e.g., skim, 2%, whole) and water. Different people recommend different ratios of milk to water in the mixture: 10% milk to 90% water, 30% milk to 70% water, or 40% milk to 60% water, always using more water than milk. The proteins in the milk interact with the sun to create an antiseptic effect. To be most effective, the milk mixture can be used preventatively by applying it in bright light every 10 days or so.
Prevention is key with powdery mildew – try to water the morning, rather than the evening, to allow plenty of time for leaves to dry during the day and choose mildew resistant or tolerant cultivars. Check seed catalogues for powdery mildew resistant zucchinis, cucumbers, grapes, and other plants.
Royal Horticultural Societyhttps://www.rhs.org.uk/advice/profile?pid=253
Master Gardeners Association of BC: http://mgabc.org/content/powdery-mildew-aphid-infestations-early-mid-fall
Sunset Western Garden Bookedited by Kathleen Norris Brenzel, p. 666
Natural insect, weed and disease controlby Linda Gilkeson, page 147-148
I planted a single hosta in my garden about five years ago and now I have a clump growing. Is this OK? Can I divide them and plant some in other parts of my garden or share them with friends?
Hostas are known to be a wonderful foliage plant for shady locations that are easy to grow. They come in a variety of sizes (from miniature to huge!) and colours (e.g., light to dark green to chartreuse to gray and blue). Colour combinations may include white, cream or yellow borders or stripes. The leaf textures vary from smooth to quilted to puckery. The flowers can also be lovely and many are fragrant.
Hostas grow best in good, organically enriched soil with regular feeding during the growing season. Hostas require moisture to thrive and must not dry out for long periods. Clumps expand in size over the years and can remain vigorous without division. Hostas also do well in containers. You can divide a hosta clump to move pieces to another location in your garden or to share it with your luckiest friends or neighbours.
Hostas can be divided in the fall or spring, although late August may be the best time to divide hostas. If doing it in the fall, be sure to do it early enough so that the roots are established before any chance of freezing weather (6-8 weeks before a hard frost). A day or two before you are going to divide the plant, moisten the soil around the clump. On the day of dividing, follow the steps below. Be sure to have the new bed prepared for the division and if you plan to share, have a pot(s) with fresh soil that you can pop the division(s) into so roots remain moist and protected until they arrive at their new home(s).
Steps to divide a hosta:
- Lift the clump with a pitch fork being careful not to damage the growing points
- Place the clump on board or plastic sheet
- With a sharp spade or old kitchen knife, cut between the shoots so you have 4-5 shoots per clump or sections can be prised apart with two pitchforks
- Replant sections in the ground at the same depth they were before you lifted the clump, with shoots poking through the soil surface
- Water the freshly planted plant sections (in ground or pots)
Sunset Western Garden Bookedited by Kathleen Norris Brenzel, p. 391 and 700
Royal Horticultural Society https://www.rhs.org.uk/advice/profile?PID=610;https://www.rhs.org.uk/advice/profile?PID=363
American Hosta Societyhttp://www.americanhostasociety.org/Education/hosta_gardening_calendar.htm
August Clinic Questions:
What Should I Do With My Raspberries This Month?
Well that depends on whether you have canes that fruit in the summer or late autumn.
Most hybrid cane fruits (including blackberries) operate on a biennial system with the canes growing during the first year and then flowering and fruiting during their second summer. Once the fruit is picked, cut down the canes to just above the ground; this will make room for new shoots.
If you have late autumn bearing canes, cut them down to just above the ground in early spring before new growth starts.
With both types, after pruning, apply a 2-3" layer of compost or aged manure and water thoroughly.
Is There Any Pruning In My Ornamental Garden I Should Be Doing Now?
Yes, August is a great time to prune some of your woody ornamental trees. Sap bleeding will be at its lowest during the day when the evaporation of water from the leaves will not only reduce the pressure in the zylem (water conducting tube) but will actually create a strong tension in the system, therefore reducing bleeding.
Ornamental trees such as Japanese maples, Beech, Birch, Oak, American Ash, Maples, all take pruning well this time of year.
Remember to clean your tools between trees and even between cuts on the same tree if disease is present. Lysol Brand disposable wipes work great for this.
Here's a helpful clean up hint if you find you get some pitch/resin on yourself while rattling around the garden. If you've got pitch in your hair, slather on some mayonnaise, leave for 15 minutes and comb out slowly; then shampoo. If you have some on your skin, hand sanitizer works wonders!
Source: The Complete Book of Pruning Coombs, Blackburne-Maze, Cracknell & Bentley. Cassell Paperbacks
July Clinic Questions:
How do I get rid of moss in my lawn?
This is a question we hear a lot at the VMGA and there’s a few different ways to tackle this issue.
First, it’s important to recognize that the underlying conditions favouring the moss need to be corrected otherwise whatever you do will be short term.
Here’s some ideas to get started:
- improve perimeter drainage
- apply lime to reduce the acidity in either the spring or fall
- aerate the soil and add a dressing of sand to improve drainage
- water properly – let grass rest during the summer if it’s established (more than two years old) and water deeply just once a month . Frequent sprinkling leads to shallow roots
- mow properly – remove about one third of the blade and mow in a different pattern each time to avoid soil compaction
- remember to leave the clippings on the grass after mowing for a free source of nitrogen
Another option is to replace your lawn entirely with something completely different. Given this summer’s drought and the prospect that climate change will likely lead to more of the same, consider this; conventional turf grass lawns typically consume vast amounts of precious water, are monocultures so frequently encounter problems, do not offer wildlife any refuge, often are a major source of fertilizer and chemical runoff into the environment and finally, they require a lot of work to maintain.
Did you know the average gardener spends up to 100 hours mowing every year?
Instead you could create a garden using native species that after just one year won’t need any watering at all.
Here’s just a few native species to consider, from groundcovers to shrubs to perennials
- Kinnikinnick (Arctostaphylos uva-ursi)
- Salal (Gaultheria shallon)
- Western Red Columbine (Aquilegia Formosa)
- Evergreen Huckleberry (Vaccinium ovatum)
Alternatively, you can learn to love the moss, which is soft, green and never needs mowing!
A few excellent resources to help get started include Native Plant Society (www.npsbc.org)
Naturescape British Columbia(www.naturescapebc.ca)
Make the neighbourhood a better place(Start something in your backyard): A resident’s guide to natural yard care for the Lower Mainland (pdf available online and relevant to all southern BC residents)
How to get your LAWN OFF GRASS: A North American Guide to Turning Off The Water Tap and Going Native by Carole Rubin (published in BC, 2002, Harbour Publishing)
When should I start thinking about planting winter veggies and what works best on our coast?
Despite the beautiful mid-summer sunshine, now is the time to start planning and planting your winter veggies.
According to Helen Chestnut, in the Times Colonist’s Garden Notes, early August is the “ideal time to seed autumn and winter green and salad vegetables such as spinach, radish, corn salad, mustards, mesclun mixes, leaf lettuce and cold hardy lettuces.” She also advises us to check out our local nurseries for “lettuce, kale, cabbage, cauliflower and broccoli transplants for fall, winter and early-spring harvesting.”
Sometimes it’s challenging to know when exactly to seed or use transplants, as well as what kind of protection to prepare for those cold winter months and when to expect to harvest outside of summer months. An excellent resource that includes a planting chart as well as details regarding cold hardy cultivars (e.g. two kinds of romaine lettuce, Winter Density and Rouge d’Hiver are generally cold tolerant) is the West Coast Seeds catalogue. Find one at your local garden centre or go online.
Finally, a fantastic resource for veggie gardeners is Linda Gilkeson, who lives on Saltspring Island and offers a wide variety of workshops in Victoria and beyond. A major proponent of gardening year round, her Year-Around Harvest: Winter Gardening on the Coast, details the benefits of winter gardening (fresh veggies when the cost of produce increases instore), what to grow and when, pest management information, planting plans and much more. Check out Linda Gilkeson’s websitewww.lindagilkeson.ca to order a book or check her workshop schedule.
So now it’s even easier to enjoy eating your own veggies year round without a greenhouse and be the envy of all those who know you!
June Clinic Question:
I’ve got Black Spot on my roses (I think). What can I do about it?
Blackspot, Diplocarpon rosae, is a fungal disease that appears on leaves contributing to overall loss of plant vigor. This disease appears as dark purple/black lesions on both the upper and lower sides of leaves. The fungus moves upwards from leaf to leaf, turning leaves yellow (often but not always) and may eventually defoliate the entire plant. The fungus may live on the ground or in the young stems and buds over the winter.
The fungal spores are spread by moist conditions, such as splashing water and once on the leaves, spread rapidly, ever upwards.
Fortunately, the rose-grower has a number of preventative options:
- Close in vigilance: Regular check ups of your roses will hopefully nip the problem in the bud! :) Inspect your roses often, check for healthy leaves, and remove any that are diseased. Do not compost infected material.
- Sanitation/Hygiene: The fungus lives in leaves on the ground, keep the area tidy of fallen leaves and debris, even during winter.
- Watering: Avoid wetting the foliage, water at ground/soil level. Too much water increases air humidity, a condition the fungus likes!
- Air Circulation and Sunlight: Provide space for air to move and to prevent the fungus moving from rose to rose. Sunlight helps to dry out the dew.
- Pruning: Remove weak, diseased, dead canes. Also prune for internal air circulation. In severe cases, the black spot is visible on the canes, prune back below an area of stem lesions.
- Resistant Varieties: Choose varieties resistant to black spot, however, there is no guarantee the variety will continue to be resistant. The Royal Horticultural Society suggests the older species are less affected overall.
Organic Spray: To change the pH level on the leaves, mix a foliar spray of 1tsp baking soda to a liter of water and 1 tsp of dish soap (non-bleaching) on both sides of the leaves. The soap helps to keep the baking soda mixture on the leaf. Repeat weekly and after rain.
Disposal: This is a determined fungus. We suggest you dispose of diseased leaves and canes in the garbage, or by burning. Do not introduce into the garden compost or add to the municipal collection sites.
Royal Horticultural Society, Rose black spot https://www.rhs.org.uk/advice/profile?PID=270
Missouri Botanical Garden, Black Spot of the Rose http://www.missouribotanicalgarden.org/gardens-gardening/your-garden/help-for-the-home-gardener/advice-tips-resources/pests-and-problems/diseases/fungal-spots/black-spot.aspx
May Clinic Questions:
What is an organic food I can feed my roses that will encourage beautiful blooms?
Roses are heavy feeders and food does encourage beautiful blooms. In addition, roses benefit from ongoing organic inputs and pre-bloom care.
Soil and Mulch: Feed and care for the soil!! Well draining organic, non-compacted soil to allow roots to spread and foster uptake of nutrients and water. A layer of organic mulch keeps the soil cooler, roots happier and reduces competition from weeds. As the mulch breaks down the roses will have a further supply of nutrients.
Fertilizer: Keep the proportions of nitrogen, phosphorous and potassium in the single digits. Higher ratios are not better. Start in the spring with a well-balanced, slow release fertilizer. Many rose growers use a granular, organic product. Apply a new layer of compost. Throughout the rest of the growing season apply monthly an organic liquid fertilizer such as fish/kelp or alfalfa/manure tea. Water well before applying liquids.
Many gardeners have used banana peels, chopped up and spread around the plant.
Other Considerations: Other aspects of care to encourage blooming include site selection, pruning to select strong, disease free canes, watering below foliage to discourage mildew and fungus.
Good Earth R.O.S.E. Care Monthly Guide (the organic side of the American Rose Society) http://www.organicrosecare.org/articles/calendar_socal.php
Spring Valley Roses Step by step Guide http://www.springvalleyroses.com/inthegarden/fertilizing.html
American Rose Society includes suggestions to compliment different styles of gardening from the casual to the exhibitor. http://www.rose.org/rose-care-articles/fertilizers-when-and-how/
Doug Hamby, Fernbank Science Center Atlanta , Georgia. Video: http://video.about.com/flowers/5-Tips-for-Growing-Bigger-Rose-Blooms.htm
What can I feed my tomatoes?
Tomatoes are a popular, edible annual requiring lots of sunlight, enough water and good nutrition. Grown in the ground or a container, tomatoes may grow in many different types of soil but like neutral Ph and soil amended with organic matter at planting time. Great soil gives the plants a good start but may not provide sufficient nutrients for the growing season.
According the University of Missouri Extension Site, too much nitrogen encourages leaves and green growth rather than fruiting. Thus a fertilizer low in nitrogen, high in phosphorus and with a medium to high amount of potassium. Secondary and micronutrients can be delivered through organic matter. The site recommends a first application of fertilizer when the plants are 1/3 grown, and a second two weeks after the first tomatoes are picked and the third a month later. The ratio of NPK is 10-10-10. Throughout the growing season add mulch to control moisture loss, weeds and prevent water from splashing plants.
The Canadian Gardener website recommends fertilizing twice monthly, using a water-soluble fertilizer (NPK 15-15-30). Here the amount of nitrogen and phosphorous is lower while potassium is higher.
Tomato Dirt is another site with interesting tomato information and a list of organic sources.
University of Missouri Extension fact sheet http://extension.missouri.edu/p/G6461
Canadian Gardener http://www.canadiangardening.com/gardens/fruit-and-vegetable-gardening/10-starter-tips-for-growing-tasty-tomatoes/a/42177/2
Tomato Dirt http://www.tomatodirt.com/preparing-your-soil.html
Ed Hulme Seeds, suggests we may over-fertilize https://www.humeseeds.com/sumtom.htm
April Clinic Questions:
What can I plant under a Walnut tree?
Planting under a Black Walnut tree (Juglans nigra) can indeed be a major challenge – according to Canadian Gardener magazine. This is because the roots, leaves, husks and buds produce a substance called juglone, which can be toxic to many plants. The poisonous zone is large too – extending 20 to 30 metres from the trunk – so it’s important to try to clean up tree debris (do not compost) and add organic materials. Some plants that are juglone tolerant and are worth trying include Virginia Creeper, Japanese Maple and European Wild Ginger. Check out this article in Canadian Gardener for more planting ideas: http://www.canadiangardening.com/plants/trees-and-shrubs/what-will-grow-under-a-black-walnut/a/29797
What can I plant under a Conifer?
A walk in the woods is in order! Typically the growing conditions underneath Conifers are considered challenging, often dry and shady to boot. However, a keen gardener can turn this challenge into an advantage simply by considering native plants. As the authors of “The New Twelve Month Gardener” so aptly write, “A walk in the woods will teach you a great deal about texture, colour and natural layering.”
Some planting ideas could include shrubs such as Huckleberry, Snowberry bush, Oregon Grape, Red Flowering Currant (a favourite of hummingbirds) or Salal. Perennials to try include ferns, foxgloves, bleeding hearts or gentians and bulbs such as camas, wild tiger lily and dog-tooth violet. Non-natives like Hardy Geraniums and Epimediums will also thrive in dry shade.
Check out some of the lovely native plant gardens nearby for inspiration – the Horticulture Centre of the Pacific, Government House and Swan Lake Nature Sanctuary.
What soil is best for flowering container garden?
This question can illicit all sorts of “animated discussion” among keen gardeners – many have their very own tried and true formula for container soils that they swear is the best of the best. Trying to keep everyone happy, I’ve turned to my trusty steed The Container Expert, by Dr. D. G. Hessayon for advice.
Clearly, as containers provide a small growing space, top quality growing mediums are important. Dr. Hessayon says that ordinary soil from the garden won’t do the trick, because it will compact, depriving plant roots of the air and moisture they need. Commercial planter soil mixes provide the right balance between good drainage and water retention.
Look for bags of either soil-based or soilless compost. The first type is best for permanent planting, as it’s heavier and holds nutrients better. For hanging baskets look for soilless compost , which is light and clean but is hard to rewet if it dries out too much. Options here include peat-based and coir-based - I think it’s important to note that peat is not an environmentally sustainable choice, so I always buy coir, a product that was previously thrown away from coconut husks and is the favourite choice of the Eden Project in Cornwall, England.
You will have to provide nutrients to your container plants. Many commercial soil mixes already contain granular fertilizer. Check labels for time limits, then provide your own fertilizer in either slow release pellet form or liquid fertilizer.
When is it safe to plant vegetables outside? What are the growth requirements?
This is a tricky question as there’s no hard and fast rule for all vegetables. For example, broad beans can be sown in February, and even in October and November (although I’ve had no luck with such early sowing) for a crop about three months later – six months for fall plantings.
Tomatoes, on the other hand, in a typical year in our area, can be successfully transplanted in late May or early June when the nighttime temperatures are reliably 10 degrees Celsius or higher.
And some vegetable continue on through the winter!
The same goes for growth requirements – each veggie has its own needs and wants for tip top production.
West Coast Seeds has a marvellous catalogue and website that clearly details timing and growing conditions for many, many vegetables from artichokes to turnips. There’s even an online Planting Chart available for download at www.westcoastseeds.com This is an excellent starting place for new vegetable gardeners.
February Clinic Questions:
What are the different kinds of garlic?
There are two main groups of garlic for the home gardener to enjoy. These are the Hardneck group and the Softneck group. In our BC climate, Hardneck garlic tends to be more reliable. Hardneck varieties such as Red Russian, Wengers Russian and Gourmet Red also supply savvy cooks with garlic scapes! (Cut off the tall flower stem that grows up and out of the bulb as they curl over, to prevent energy from going to seed production instead of the bulb itself.) Scapes can be stir fried or steamed.
Late October-November is the best time for you to plant garlic and it can be harvested in July. A reliable way to tell if your garlic is ready is to watch the leaves wither and yellow to about 2/3. Hang in a cool dry area until the skins appear papery and white; the bulbs can be stored for 4-6 months.
Garlic can be easily grown in containers as long as they are well draining, non frost-cracking and can be kept moist from planting to harvest time.
Garlic is a great companion plant in your ornamental or edible garden too; it is a natural organic repellent for aphids and spider mites!
Sources: Encyclopedia of Natural Insect and Disease Conrol, Rodale @ 1984 , A Year on the Garden Path, C. Herriot @ 2005
Can I start seeds now?
There are several seeds that you can start indoors in February in Coastal BC. Bottom heat and full spectrum fluorescent lights will help ensure success. Most seeds germinate most reliably at a soil temperature of 20-25C. Covering the seed trays with plastic and having bottom heating mats or heating coils are effective and low cost both in energy terms and purchase price. Bright light is often crucial for both germination as well as plant growth, thus, sow the seeds thinly and lightly with just a thin layer( a good rule of thumb is twice as deep as the size of the seed) of sterile potting mix over top the seeds. Consistent, soft watering is also important. A brass water mister on the end of your hose is a good tool to use at this stage of plant development.
Some edible seeds you can start now include: artichoke, leeks and asparagus. Some herbs to start now include slower germinators such as lavender, rosemary, oregano and bergamot. In addition, you can get a head start on your ornamental flower garden by starting annuals and perennials such as marigolds, viola and columbines. Of course, there are many more plants you can start now and a good planting chart can be found on the West Coast Seed website at the following link:
Source: West Coast Seed Guide 2005, 2014
November Clinic Questions:
Can I grow tomatoes in Victoria during the winter months?
Tomatoes require a certain number of growing degree-days in order to bloom, set (assuming pollination) and ripen plus sufficient hours of light. Tomatoes need warmth: warm days in the 15-17 C range and night temperatures above 10 C (the base temperature is 10 C meaning tomatoes will not grow below 10 C). At least 8 hours of sunlight, ideally in full sun. It would be possible to provide these conditions in a heated greenhouse, but would be expensive to maintain.
Source: Colorado State University Extension athttp://www.ext.colostate.edu/mg/Gardennotes/717.html
What part of the Dahlia did the Aztec’s eat?
Distinct from the fancy Dahlia of our gardens, the Aztec diet included the indigenous Dahlia pinnata found in the mountains of southern Mexico. This dahlia plant is very tall, up to 20 feet, tree-like and was known as acocotli or “water cane” according to the 1570 account of physician Francisco Hernandez. The tubers were eaten and the stems used as a water source when travelling. The Dahlia is the national flower of Mexico.
Sources: Stanford Dahlia Project and the Victoria Horticultural Society
What can I plant in my fall container? I have an evergreen perennial already – what else do I need?
A garden in a freeze proof pot! Remember the basic design principals: Colour, Shape, Texture, Form, Line and Scale. Choose combinations pleasing to the eye, proportionate to the surrounding landscape. More contrast means greater drama! Being a mini-garden, selection is crucial to health and growth plus size and site of your container.
Ensure that each plant will work with available container space, anticipated moisture levels, hardiness, sun/light and soil conditions for your container’s site and seasonal weather changes. Growth rate and mature plant size are also important considerations.
Use the evergreen perennial you already have and combine it with two or more of these year round interest evergreen plant possibilities:
- Carex (Sedges)
- Dwarf conifers – a wide variety of fir, pine, cypress, yew and spruce
- Autumn Fern - Dryopteris erythrosora
- Sword Fern - Polystichum munitum
- Holly Fern - Polystichum makinoi
- Hart's-Tongue Fern - Asplenium scolopendrium
- Deer Fern - Blechnum spicant
- Heuchera - many to choose from
- Hebes - hardier varieties
- Rhododendrons - dwarf/compact varieties
- Saracocca (sweet box)- great for by the doorway
- Skimmia - dwarf/compact varieties
Your possibilities are endless.
A few other tips to keep in mind
- plant in multiples of 3, 5, 7 ...... odd numbers are pleasing to the eye
- don’t be afraid to overplant
- container plantings lose at least one zone in hardiness (versus being planted in the ground), and more for elevations (higher floor balcony/terrace)
- use a potting soil mix that will allow for good drainage
- don’t panic, if your plants eventually get too large for your container, it’s easy to relocate them in your garden or give themaway.
Enjoy your new container!
Sources: The Pacific Northwest Gardeners Book of Lists, Ray and Jan McNeilan, 1997; Container Gardening, Fine Gardening vol. 7, 2010, Perfect Plant Perfect Place, Roy Lancaster, 2002 and Great Plant Picks www.greatplantpicks.org