If heavy, pounding rains or hailstorms are common in your area, protect large-flowered chrysanthemums with a frame covered with cheesecloth or soft plastic sheeting. When plant tops die after blooming, cut them to the ground. Clean up fallen leaves. Remove the mulch you applied at planting. Burn all refuse.
New shoots begin to grow late in the fall.
Protect them from frost by putting down new mulch. Diseases Many diseases attack chrysanthemums. Although diseases rarely kill, they damage and often disfigure plants. Water early in the day so leaves can dry before nightfall. Fungus diseases thrive on wet leaves.