This week's question is all about container gardening on a sunny patio of a condo tower. The answer includes recommendations for sun-tolerant plants, as well as tips for planting and maintaining a container garden in an exposed environment.
Question
I am excited to get my deck ready for the season. I’m located in a condo tower, facing south. It gets hot and very windy at times.
While I am reading a lot about container gardening, I am a bit overwhelmed with decision making.
I have a large 16” wide container that I would like to fill. What do you recommend that could tolerate the intense summer heat and wind?
I have had good success with geraniums, portulaca, and lemon verbena. Not so much with nasturtiums and petunias. The petunias were planted with tomatoes so not sure if that caused the issue.
Answer
Container gardening can be a very creative and rewarding experience. There are dozens of easy ways to make it a success.
Take caution when reading articles about container gardening in regions where the climate is not like ours. Full sun can be very hot in the Okanagan! If your plants are receiving too much sun, you might even consider installing a sun shade.
Fortunately, there are many beautiful annuals and perennials that do well in containers, even in the hot Okanagan.
Here are a few ideas to consider:
- Containers can look fabulous with "a thriller, filler and spiller." For example, something tall (such as a canna or dracena spike placed at the back of the container or in the middle); then adding plants to fill in as mid-height flowers such as geraniums; and lastly something to cascade over the side such as trailing potato vine or asparagus fern. Other suggestions are annuals such as Livingstone daisy, lobelia, zinnia and gazania.
- You could also try perennials, for example Scabious Mars Midget. The Okanagan Xeriscape Association highly recommends this plant for containers. It has excellent heat resistance and low water needs. To see an image, go to Scabious Mars Midget - Okanagan Xeriscape Association. The Association's website lists many other perennials, including stunning and delicately coloured grasses that would do well on your deck.
- As for the 'poor performance' of your petunias that were planted with your tomatoes: we suggest that you plant them separately in different containers, as they each have particular water, space and nutrient needs.
- Because of your location, check your containers twice a day, even more on hot and windy days, to ensure they don't dry out.
- Plants in containers also need regular feeding with a balanced fertilizer (e.g., 20-20-20). Depending on what you choose to grow, a nursery can advise you on what and how to feed your plants.
- For a wind break, and if you have a railing, you could try planting scarlet runner beans and weaving them between the rails.
- If you're replacing your soil this spring, clean your pot with dish soap and hot water. Then fill the container with as much soil as possible. Adding water retaining crystals (agro-polymers) is an asset. Don't fill the lower portion of your pot with milk cartons, rocks or Styrofoam as there is then less soil to absorb moisture. Drainage is important so make sure that your pot has a drainage hole. If you're concerned about soil running out the bottom, cover the hole with a coffee filter.
- After planting, top-dress your soil with 1-2 inches of mulch to retain moisture. This will help keep the plant roots cooler in hot weather. It looks nice too!
- If, in the future, you decide to add another pot or replace your existing one, remember that 'bigger is better.' Choose one that's light in colour to reflect the heat, and one that's ceramic, concrete or double lined vinyl. Other types tend to dry out quickly.
Answer by:
Volunteer Master Gardener Advisor
Okanagan Master Gardeners
A chapter of the Master Gardeners Association of British Columbia
References:
- Okanagan Supplement
- OXA
- David Tarrant: Highrise Horticulture
