I've been reading up about propagation. Most of the books talk about using cold frames for getting baby plants through the winter before setting them into the garden.
However, we get very cold winters (down to 20 below) and lots of snow where I live (right on the border of zone 5 on a hillside that flowers later than everything in town.) I can build a frame facing south, but heat isn't an option and when the snow is deep I can't get to where the frame is going to be without a lot of hassle. So I'm wondering what kinds of plants would do okay in the cold frame. I'm looking to propagate some ground cover, cranesbill geraniums, and lots of hardy dianthus.
Any tips? Is it worth doing?