Do you want flowers or just ground cover plants? Annuals or perennials? For a school garden, it is nice to have plants that flower in spring or fall when the kids/teachers are in school to see them. I find that early bulbs such as snowdrops, narcissus poeticus, siberian squill etc. are really easy and low maintenance. Then pick some fall-flowering plants such as Japanese anemones, pink turtlehead, etc. for late colour. Shade annuals include impatiens and fibrous begonias, but I think that it is too late to start seeds of these now. Both of these are slow growing from seed and have to be started very early. Also small flats/trays of blooming plants can be purchased quite cheaply in the spring. Maybe you could put a small notice in your school paper or on a notice board in the teachers' room asking for donations of shade tolerant plants for your garden.

Ontario:

Great ideas! Thanks so much!

Megan