Did you know that mums (chrysanthemums) don’t have to only last one season? With a little work, your hardy mums can survive the winter!
A very important part of winterizing your mums begins when you plant them. Make sure that the soil drains well so puddled water doesn’t form ice on the roots! It’s not the cold temps, but usually ice on the roots that kills your mums. After a few hard frosts, the leaves on your plant will turn brown and die, now is the time to cut back, to about 3-4 inches. If you cut it too far back, less fresh stems will grow back in the spring.
After the ground freezes, you will want to cover the plants with leaves and mulch. A nice heavy layer. This is to keep the ground from thawing out and re freezing, which is not good for the plant!
Your other option is to pull the plants before the first freeze. Clean the roots of dirt (or bugs). Some gardeners use a disinfectant or a hot water dip to control eelworm. The recommended treatment is five minutes in water at 46°C (114°F). After this, dry the stools thoroughly, trim the roots to about 15cm (6″) in length and then box them in seed trays using an open compost. Store in an airy place (a cold greenhouse is fine) and keep the compost dry. Plants grown in pots can be moved into a cold greenhouse, or some other sheltered place and, as above, kept dry.
In the early spring, start watering to encourage growth. Remember not to put Chrysanthemums outside, in the spring, until the danger of frost has passed.