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When do I plant new raspberry canes?
Raspberries belong to the rose family and form a large group of fruits known as brambles, all in the plant genus Rubus. Red raspberries (Rubus idaeus) are native to northern North America and Eurasia. Cultivated red raspberries were introduced into the United States as long ago as 1771. They have perennial roots and crowns and produce new canes from buds that grow on the roots and crown in some species and only on the crown in others. In the first year, canes are called primocanes. In the second year, they are called floricanes. Both primocanes and floricanes are present during the growing season.
There are two types of red raspberries. In summer-bearing cultivars, the second-year floricanes bear a crop in early summer and the first-year primocanes are vegetative (i.e. having only leaves, not fruit). Fall-bearing cultivars produce a significant amount of fruit at the top of the primocanes in the fall. The easiest way to manage fall-bearing raspberries is to cut the primocanes to the ground each winter after fruiting. If you keep them for the second year, however, they will produce a crop on the floricanes the next summer. Because primocane-fruiting types can be double cropped, they sometimes are called everbearing raspberries.
Black raspberries (Rubus occidentalis), sometimes called blackcaps, are native from the Northeast to the Great Plains. The native western black raspberry is R. leucodermis. Black raspberries produce canes only from the crown, not from the roots. Tip primocanes in summer to encourage branching. These canes produce fruit the following year. In the early 1900s, there were dozens of black raspberry cultivars, and new cultivars were released until about the 1960s. Until recently, there has been little breeding work on black raspberries, and only a handful of cultivars are now commonly available. In the Northwest, nearly the entire commercial crop is ‘Munger’, a cultivar released in 1890.
Purple raspberries are a hybrid between black and red raspberries. They tend to be vigorous, crown-forming plants with large, soft fruit. Purple raspberries are generally considered to have only fair quality for fresh use, but they are excellent for processing.
Raspberries are not just another tasty berry crop; they are loaded with healthful attributes. They’re high in fiber and contain vitamin A, folate, antioxidants, and numerous minerals. The juice contains vitamin C, and those sometimes-annoying little seeds contain vitamin E.
Planting:
Purchase dormant, certified plants at a garden store or nursery. Sucker plants dug from an established planting during the winter when plants are dormant often have virus diseases that can survive during transplanting. Plant raspberries any time the soil is workable between November and the end of March, while the plants are dormant. Do not use any planting stock that has started to bud out appreciably, as it generally does not perform well.
Prepare the site for your raspberry canes by digging in organic matter (compost or manure) 2 feet deep before planting. The soil must be well drained as excessive soil moisture during the late winter when new roots are growing leads to root rot. If your soil is heavy and tends to remain wet, you may have a problem growing raspberries. If this is the case, consider using raised beds at least 12 – 18 inches high. Plant raspberries in a full sun location as plants grown in shade will remain small and produce tart fruit. Raspberries grow best in loam or sandy soil that is at least 24 inches deep.
Space plants 18-24 inches apart along a fence, trellis, or support wires. Allow 6 feet between rows, and do not plant too deeply. The first roots should only be about 2 inches deep, and look for the previous soil mark on bare rooted plants as a guide to planting depth. Cut canes back to 5-6 inch stubs after planting (however, don’t prune summer fruiting raspberries bought as ‘long canes’ or you will not get fruit the first season). (Containerized raspberry and blackberry canes do not need to be cut back). New canes will begin growing from the roots and soon after the tips appear apply a blood, fish or bonemeal fertiliser or a commercial 5-10-10 or 5-10-5 fertiliser, six inches out from the plants and water in well.
To keep your plants healthy and productive, make sure they don’t dry out in the summer. Water with drip irrigation or a soaker hose so that foliage stays dry to reduce the risk of fungal infection. This is also where mulch is so important. Surround your newly planted canes with a dense layer of mulch, approximately 3 inches thick, to help retain moisture. Mulches, including compost, can be applied at any point during the growing season although it is most convenient for gardeners to do it in early spring before planting or before plants emerge, or in the fall as plants start to go dormant but before the ground freezes. For early spring applications, it is typically best to wait until the ground starts to warm as putting down a layer of mulch too early can further insulate the ground and slow plant emergence. For late-season applications do not place the mulch on too early, as it can slow plants from going dormant and make them more susceptible to damage from cold temperatures.
Compost can be layered on top of the soil as a mulch or used in conjunction with straw, leaves, grass clippings (fresh or composted) or newspaper. While this mulch material will not have the same level of weed suppression as other organic mulches, it can help to improve soil structure and drainage, as well as increase soil fertility. It is better to leave leaves whole and not shred them, as many eggs and cocoons of beneficial insects overwinter on the leaves and are destroyed when the leaves are shredded.
Note: Some gardeners use chipped or shredded cedar mulch, but it has been found to repel many beneficial insects and therefore straw, compost, leaves, and grass clippings, individually or combined, provide a more appropriate mulch around both newly planted and mature raspberries (hay can be used too but tends to sprout a lot of grass seeds creating more weeding). These offer a better choice than cedar for this purpose and will maintain ideal conditions and a healthy soil environment for the plants.
Pruning:
Consistent pruning each year will keep plants from becoming tangled and will produce better fruit. Raspberries bear fruit on young new canes. After bearing fruit, canes become brown and dry and will not produce fruit again. Cut old canes to ground level as soon as possible after berries are picked. This allows sun to reach the new canes. Keep 4-5 of the thickest new canes per hill and cut weakest canes (under pencil size) to the ground. Cut undesired suckers to ground level. Keep a maximum of 4 to 6 canes to a plant if trained as a hedge.
In subsequent years, top-dress the freshly pruned plants with several inches of manure or compost and if necessary, a sprinkling of lime to reduce the acidity of the soil. The soils of the Pacific Northwest tend to be acidic.
Disease issues: Most raspberry cultivars are sensitive to Phytophthora root rot; this disease is a much greater problem in Oregon and southern Washington than in northern Washington and British Columbia. Growing raspberries on very well drained soils or raised beds or ridges will help avoid the disease.
Sources:
https://extension.oregonstate.edu/catalog/pub/pnw-655-raspberry-cultivars-pacific-northwest
https://s3.wp.wsu.edu/uploads/sites/2076/2021/09/C116-Raspberries-format-update-21.pdf
https://www.rhs.org.uk/fruit/raspberries/grow-your-own
https://s3.wp.wsu.edu/uploads/sites/2076/2021/09/C116-Raspberries-format-update-21.pdf
My own raspberry patch
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