While the yellow, red, orange and rust colors of mums (Dendranthema x grandiflorum), also called chrysanthemums, are associated with fall, mums can bloom in spring. Garden mums grow in U.S. Department of Agriculture plant hardiness zones 4 through 9. The conditions for mums to bloom can be right in spring as well as in fall. Early-blooming mums can be cut back or allowed to flower.
Flowers of Dark
Mums need shorter days, with nine or 10 hours of darkness to flower. Normally this night length causes mums to flower in September and October. Because this also happens in spring, mums may bloom early in the year. When this happens, mums can be cut back to prevent flowering, but this is not vital to fall flowers. The mums can be allowed to flower and then be deadheaded. Either method will result in mums producing fall flowers.
A Little Pinch
To produce full, bushy mums with plenty of blooms, pinch back your mums throughout spring. Mums that are not pinched back cam develop tall, weak stems, resulting in fewer flowers and stems that may not be strong enough to support the flowers. When the plants are 6 to 8 inches tall, the light green growing tips should be pinched off to encourage branching. New branches will develop along the stem. Early-flowering mums that are cut back after flowering will branch out like pinched-back mums and flower again in fall. The nonflowering stems can be pinched back while leaving the early flowers on the mum. Stop pinching in mid-June to allow the stems time to develop fall flowers.
When fall blooming starts, remove spent blooms. Once the entire mum has stopped blooming in fall, cut the plant back to the ground. Cutting back the mum will remove old growth and help prevent winter damage and diseases. Next spring’s new shoots will begin to develop in the late fall. Adding a layer of mulch can help protect these new shoots from cool weather, especially in areas that get freezing temperatures.
Purchase with Caution
Not all mums will grow well in the garden. Varieties labeled “florist mums” are short-lived and usually only grow one season. Hardy or garden mums produce shoots underground that allow the mums to grow from year to year. Florist mums produce few or no underground shoots and die easily during the winter. Commercial growers produce florist mums in greenhouses or in protected frames. If you're willing to give florist mums similar protection, you may be able to keep them growing for more than one season.
- Plants for a Future: Dendranthema x Grandiflorum
- Utah State University Extension: Growing Chrysanthemums in the Home Garden
- University of Florida IFAS Extension: Mums the Word
- North Carolina State University Extension: Guide to Successful Outdoor Garden Mum Production
- University of Arkansas Extension: Perennials -- Chrysanthemums (Mums)
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