To winterize chrysanthemums, cut them back, remove the summer mulch, surround the plants with winter mulch, and water them regularly. This process requires pruning shears, water, a shovel and winter mulch.
Chrysanthemum winterization begins after the first frost. Cut the plants back, leaving 3 to 5 inches of stalk above the ground. Remove the existing mulch, and spread a 1- to 2-inch layer of thick winter mulch around the stalks. Compost and evergreen clippings are effective winter mulches.
Monitor and water the plants throughout the winter season. Keeping the plants watered is particularly important in areas where snow does not frequently accumulate.