A Pinch Can Improve Mum Plants’ Production

Question: Are chrysanthemums difficult to grow? What specific care do they require to make them produce lots of blooms in fall?

J.F., Stanton

Answer: There are more than 150 different species of chrysanthemums, or “mums.” One of the most common is C. maximum, the Shasta Daisy, which is a popular spring- and summer-bloomimg variety.

The daisies are easy to grow, bloom a long time and are great in borders, as well as flower arrangements. They prefer sun or part shade in hot summer areas. They come in many forms, but all varieties are white with a touch of yellow.

Popular varieties are Esther Read--the most popular double white, with the longest bloom (a great flower for cutting) and Snow Lady, a single that is easy to grow by seed, reaching a height of 10 to 12 inches and blooming almost continuously.

The most challenging mums to grow are the fall-blooming types. Flower forms are referred as exhibition, spider, decorative, pompom and button types. They require more care, including deeply cultivated, enriched soil and regular pruning to limit the number of stems and increase bloom size.

Potted-flowering mums that are often given as gifts are usually fall-blooming varieties and can be planted.

Here are some general care requirements, which apply to most chrysanthemums:

* Plant in well-drained garden soil. Avoid placing near large trees or shrubs with invasive roots. Provide sun (at least five hours per day) or part shade in hot summer areas.

* Give them plenty of water, especially before and during bloom.

* Feed plants two to three times during the growing season with a liquid fertilizer to encourage large flowers. Make the last application with low-nitrogen fertilizer not less than two weeks before bloom. (Stop feeding once the buds show color.)

* To produce sturdy plants and big blooms--pinch! Start at planting time and remove the new plants’ tip. Lateral shoots will form. Select one to four of these for continued growth.

Continue pinching all summer, nipping top pair of leaves on every shoot that reaches 5 inches in length. Avoid pinching past mid- to late July because you may remove tiny buds.

* In our mild climate, mums will continue to grow throughout winter. To avoid having tall, leggy plants with few blooms in the spring, trim them back to 5 to 6 inches above the ground after they finish blooming in late fall or early winter.

* Divide plants as necessary in spring. Do so when the new growth is about 4 inches high. Discard the old center portion of the root mass and plant the young offshoots 18 to 24 inches apart.

* Two mums--Pyrethrums (C. pacificum) and feverfews--like average to poor soil. All others like rich soil and plenty of nutrients (not too much nitrogen.)

* On taller varieties, stake individual stems as necessary.

For further information, contact the National Chrysanthemum Society, (703) 978-7981.

Sunnyslope Gardens in San Gabriel also specializes in chrysanthemums. (626) 287-4071.

Have a problem in your yard? University of California Cooperative Extension (UCCE) Master Gardeners are here to help. These trained and certified horticultural volunteers are dedicated to extending research-based, scientifically accurate information to the public about home horticulture and pest management. They are involved with a variety of outreach programs, including the UCCE Master Garden hotline, which provides

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