Can you suggest great winter gardens and/ or roof gardens that use native plants? I would like to visit them.
Thank you for contacting the Toronto Master Gardeners with your interesting inquiry.
You did not mention if you were planning on viewing these gardens in the Toronto area or else where. Doing a google search I have found a number of green roofs in the Toronto area.
The first is the green roof located at the top of the Native Child and Family Services. building. The project converted a 1980s office building into a centre offering social and cultural support services for the aboriginal community in downtown Toronto.
The Toronto Botanical Garden has also installed a green roof on the Dembroski Centre for Horticulture that is over 2400 square feet. You are not able to tour this green roof, however there are a number of knowledgeable people available to answer your questions.
As for public gardens this is an excellent article which lists the top 10 public gardens in Toronto.
I hope the above list gives you a good place to start.