Growing Stevia in Zone 3

I live in central Alberta, Canada, where the growing zone is 3. I have read the zone for growing Stevia is 11+. Is it possible to grow such plants in a greenhouse or indoors?

Definitely yes! A greenhouse will do quite well. Your much longer days in summer will make up for the relatively low position in the sky of the sun. Keep the plants cool and on the dry side during the winter. Windowsill culture is possible too. Put them into the sunniest spot -better yet out of doors - during the summer and find a cool bright spot for them indoors in the winter.