Live in Toronto, small backyard patio with a fence around it. Looking for some tall, narrowish trees or shrubs that need little to no sun but will be colourful or interesting and can live in a pot. Happy to have something I need to shape or prune to keep it narrow, but I need a bit of height in my boring backyard. 3-5 feet would be ideal.
Thank you for contacting the Toronto Master Gardeners
There are a number of issues that must be tackled when overwintering shrubs in containers. The shrub you choose will experience freeze thaw cycles during the winter which many plants have trouble surviving.The freeze-thaw cycle is the main problem: that is, the melting of the water in the container’s soil during sunny or warmer spells, followed by freezing when the temperatures dip again. This is what kills a plant’s roots over the winter. Your most important starting point is the container itself: it should be as large as possible (the more soil it can contain, the more insulation it will provide). Ensure that the containers are freeze-thaw resistant. Ceramic and clay pots will probably crack as will cheaper plastic pots. This link on overwintering perennials in pots might be helpful.
When choosing plants you are best choosing plants that are tolerant of colder temperatures, rather than near-by plants that are planted in the ground. Toronto is a zone 6; I would choose plants which are hardy down to a zone 4.
Aronia melanocarpa, Stephanandra incisa ‘Crispa‘, Symphoricarpos albus, Symphoricarpos orbiculatus, Viburnum trilobum, and Clethra alnifolia are all shrubs that will grow in part shade (2-4 hrs. of sun).
Ornamental Shrubs for various Light Conditions: A Toronto Master Gardeners Guide gives a more extensive list of various shrubs that will grow in shade.
Another possibility that you might consider is planting an annual vine. One suggestion would be Thunbergia alata. This vine also requires a minimum of 2-4 hours of sunlight in order to flower.