Chrysanthemums can be treated as an annual or perennial. While many big-box stores and nursery centers offer fall mums in pots as annuals each autumn, you can actually grow mums as perennials by planting them in the spring. Hardy mums will come back year after year, although they perform better with a little over-winter help. To increase your mums' chance of survival, get them in the ground in the springtime, this allows them to build a strong system of roots and branches. Fertilize regularly throughout the growing season, but stop before the fall: late-season fertilization can keep the mums growing, and prevent them from entering the dormant state that helps them survive the winter. As frost approaches, add mulch or a few inches of hay at the base of each plant, to protect the roots from freezing. Do not cut the branches of your mums back until spring. Chrysanthemums have a better rate of survival when allowed to remain as complete plants throughout the winter. Plus, the flowers and foliage of your fall mums will harden into interesting and visually-appealing dried branches. When springtime rolls around, it's time to revive your mums. After the last frost, prune the dead foliage down to the ground, and add fresh soil to the planting location. Begin fertilizing again, and water your mums well. As your mum plants bounce back, they may produce early spring buds. Pinch those buds back, to allow the plant to conserve energy for healthier foliage and another beautiful fall display!