I grub mine out of the planters and just pot them up in "something" small for the winter. Smaller hanging baskets work pretty good. Obviously I cut them way back before doing this. Since I have a large greenhouse I have the room to do this. I remember one year they looked pretty atrocious come May..........I had started moving things out, but just took those baskets and set them outside till I could get to them. Well, well...........we had a couple of nice rains before I got them planted back in the planters and they took off like gangbusters. I overwintered some for 3 years before I let them go. It's fun buying new ones too.
