Hi Mark, I'm Brian. I have a cacti bed in my yard in southern Ontario. I can't say they shouldn't be growing here as we do have one opuntia species that is native to here but they are very rarely grown outdoors here. My bed is free standing in my back yard and is a raised bed filled with soil, sand and lots of gravel. I grow mostly opuntia but do have a couple others whose names escape me at the moment. I only cover individual plants that have more difficulty with the snow ( I've had as much as 4 feet covering them). Last fall was a wet one and I had quite a rot problem going on but that seems to have fixed its self with the warmer dryer weather. I've add a picture of my bed and have others if your interested.
