Helping Nebraskans enhance their lives through research-based education.
by Don Janssen, UNL Extension Educator
You might say that chrysanthemums are the stars of the autumn perennials garden. They bloom profusely and continue to bloom after the first frosts have zapped tender annuals. Mums offer a seemingly endless variety of flower sizes, colors and shapes. And, because they are perennial plants, they come up and flower year after year without replanting.
Fall is a good time to select mums because you can see firsthand what each variety has to offer. You can buy plants in bloom and simply pop them into sunny spots in the garden for instant and continuing enjoyment. You can also plant flowering plants in the spring or rooted cuttings.
The best spot for mums combines fertile, well drained soil with plenty of sunlight. Mulching around plants is a good idea. In the spring, summer and fall, a couple of inches of coarse mulch suppresses weed growth and conserves soil moisture. In the winter, 3 to 4 inches of mulch protects the plant's crown from freezing and frost heaving.
After plant tops die in the fall, cut them to the ground and dispose of them away from the planting site. This removes any disease organisms that might be present on the old foliage or stems. Then mulch.
In the spring, remove about half the winter mulch in early April and loosen the rest. Finish removing the winter mulch in early May.
Mums are generally easy-care plants except that they need pinching in the spring and summer to form bushy, compact plants, and they grow quickly and need dividing about every two years.Pinching is simply removing about a half-inch from the growing tip of each stem every two weeks from the time new spring growth reaches 6 to 8 inches in height until about July 15. Without pinching, plants tend to develop tall, weak stems and few flowers.
Dividing plants every other year reduces crowding, which can contribute to foliage disease development, and provides new plants for the garden. Divide plants in the spring, after the average date of the last killing frost. Lift plants out of the soil and gently wash some of the soil from the roots. Each old plant will be surrounded by several small new plants, each with its own roots. Separate the plants carefully, replant the small ones and discard the old ones.
To reduce the chance of disease in mums, plant in well drained areas with good air movement. Plant low-growing, bushy varieties 2 to 2 1/2 feet apart and other, more compact mums 1 to 1 1/2 feet apart to minimize crowding. Good air circulation around plants is important in preventing the development of fungus diseases, which thrive on wet foliage.
Water mums deeply once a week during dry weather, keeping water off the foliage as much as possible and watering early in the day so leaves can dry quickly.
Several plant diseases and insects can plague garden mums. A well selected planting site, proper spacing and a fall garden cleanup can go a long way to preventing pest problems.
University of Nebraska-Lincoln Extension in Lancaster County is your on-line yard and garden educational resource. The information on this Web site is valid for residents of southeastern Nebraska. It may or may not apply in your area. If you live outside southeastern Nebraska, visit your local Extension office
Contact Information University of Nebraska-Lincoln in Lancaster County
Web site: lancaster.unl.edu
444 Cherrycreek Road, Suite A, Lincoln, NE 68528 | 402-441-7180