Q: There are so many beautiful varieties of mums at this time of year. They are supposed to be perennial, but I lose them over the winter.  Is there a trick to get mum plants to overwinter?    

A: Hardy mums (Dendranthema, formerly Chrysanthemum) come in a wide variety of colors and shades of yellow, red, orange, white, and lavender. They require full sun and a well-drained, moist soil. Even though they are cold-hardy to Zone 5, it is often difficult to overwinter them in northern areas. Mums planted in the spring are much more likely to come back the following season because they have an entire growing season to become established. Sometimes gardeners will overwinter potted plants in cold frames or cool basements and plant them in the spring. Allowing dead flowers and stems to remain for the winter to collect plant debris will help insulate the roots.  Dead stems should be removed in the spring just as new growth begins at the base of the plants. A well-drained soil is essential for their successful return in the spring.