There was a thread earlier this year where growing apples in Zone 3 Canada. But there is at least one post suggesting sources in Canada.

Also Cornhill Nursery, I’ve ordered roses from them before and was happy with the quality & process, https://www.cornhillnursery.com/Ornamental%20Shrubs.html

Thank you both for the info, I'll check them out!

Whiffletree is good, Silver Creek as well, Boughen nurseries there are two, one out of Nipawin Sask. and one out of Manitoba, T&T seeds has some, Tree eater Nursery out of BC. and for small fruits and berries I like Lareault Nursery, Oh and Hardy Fruit Tree Nursery.

T+T seeds has a variety of apple trees reasonably priced. The benefit of getting trees from them is they are all varieties that are developed and grown on the Prairies so they are pretty winter hardy

I just received a batch of native eastern trees (bitternut hickory; American beech; sassafras; American chestnut; mockernut) from Nutcracker nursery. They're all right, but shipping is outrageous, ($87 to Alberta for 500 grams of bare-root trees), and several seedlings were broken on arrival. I'm giving them a pass this year, as things have been so strange, but I may not buy from them again.

Acorus Restoration in Ontario is excellent. They stopped selling for a few years, but I see that they've started up again. Prices are great and shipping is reasonable, so I'll try another order from them in the fall. Next year I'll try Grimo Nut Farms, as they have an interesting selection of nut trees. Honeytree Nursery in PEI also sells a variety of interesting trees, and it's worth looking at their website.

Hortico is a Canadian nursery in Ontario, it sells trees and shrubs: https://wholesale.hortico.com