I am trying to make a native plant garden however I do not know when to start planting these plants. Does it depend on the plant itself? The garden is located in north east Scarborough, the soil is clay, maybe compacted but wild strawberry ground cover and a native creeper rose seem to be thriving. The garden is north facing but gets enough sun to qualify for part shade in areas.
Another question I have is about the goldenrod in my garden. Coming out of winter it seems the stems are all hollow and dead, but maybe the roots are alive, should I do anything to help the goldenrod? It grew to be 5’3’’.
Thank you so much for taking the time to read this. Looking forward to hearing from you guys!
I think you have made an excellent choice to plant native plants in your home garden!
According to Natural Resources Canada, Toronto lies in the plant hardiness zone 7a and Markham in zone 6a. Depending how far north you live in NE Scarborough, your garden will be somewhere in between the two zones.
Plant hardiness zones are a good guide when choosing plants for your garden. If you choose native plants that prefer to grow in zone 6a-7a you won’t have to work as hard to protect your plants over winter, they will require less summer watering and will attract fewer pests.
Planting conditions for native plants are not that different from non natives. If you are planning to plant this spring it is best to wait for the ground to thaw in your area. If you choose native perennials that are not frost hardy, they will have to wait until May. The last frost day in Toronto falls between May 11-20 this year.
Most native plants that grow in your area prefer well draining, nutrient rich soil- unless you are planning a rain garden or pond edge. The native soils of Toronto have some clay, but tend to be forest soils- so have a thick layer of leaf litter which breaks down and improves soil drainage and the amount of available nutrients in the soil.
If your soil is compacted clay in the areas you would like to plant, you can mimic the native soil by adding well rotted or store purchased compost, after planting, then top with shredded natural cedar mulch. The compost will give your natives an extra nutrient boost, and the mulch will hold the compost in place, prevent further soil compaction, slow down the water evaporation rate in summer and improve your soil structure over time.
If you are planting perennials or small shrubs add 1 inch of mulch over 1 inch of compost. If you are planting trees or larger shrubs I would double that- with 2 inches of compost first, then 2 inches of shredded mulch.
As your mulch decomposes, you will notice the compost and mulch levels diminish over time, so you may need to top it up every few years.
If you are planting trees or shrubs leave a 1-2 inch space between the plants trunk and the mulch. This is important to prevent the trunk from rotting or attracting fungal diseases.
If planting in clay, dig your planting holes wider than the plant pot, but not deeper. Break up the soil at the edges of the hole and blend some of the existing soil in with a good quality planting soil. Avoid soil blends that contain large amounts of peat moss as this will hold water and could drown your plants if they are planted in heavy clay.
I have attached two lists of native plants that will grow in your area. One was prepared by the City of Toronto and has a reasonable range of perennials and a few grasses for a range of light conditions. The second list was prepared by the City of Guelph Healthy Landscapes initiative, and lists a large range of native plants. Also, look for natives that grow in clay soils.
As far as your goldenrod goes, you can prune it back fairly hard. If it is in relatively good condition and you like its shape, prune it back by 50%. If the stems have been crushed by snow, cut it back to 6-12 inches above the ground. This will encourage new spring growth.
Happy native species planting!