I am overwintering my geraniums in cardboard boxes this year. If you have room in your garage or basement, consider saving your geranium plants too. I lift my plants from the ground with a spading fork and brush away as much soil as possible. After they are stored in boxes, I will check the plants each week to remove dead leaves. It’s also a good idea to inspect the geraniums every few weeks for the development of mold or mildew.
“Susan’s in the Garden,”video tutorial demonstrates two techniques for over-wintering your geraniums.