You probably think of mums as boring. They’re everywhere at this time of year. Many consider them a bit of color on the front porch that you compost after they’ve finished flowering. But mums have a lot more to offer than that.
Mums are in their prime as early as September. We tend to think of chrysanthemums at Thanksgiving as temporary filler plants for fall containers and borders but mums are perennials and can play a bigger role in your garden if you let them. Established mums can tolerate quite a bit of neglect and still keep blooming every year.
Chrysanthemums were first cultivated in China as far back as the 15th century. Over 500 cultivars had been recorded by the year 1630. In Japan records go back all the way back to the 8th century relating to mums.
The botanical name for the garden chrysanthemum has been changed to dendranthemum grandiflorum, but I never hear anyone use this name. It doesn’t exactly roll off the tongue.
Yellow or white chrysanthemum flowers of the species. C. morifolium are boiled to make tea in some parts of Asia. In Korea, a rice wine is flavored with chrysanthemum flowers. Chrysanthemum leaves are steamed or boiled and used as greens in Chinese cuisine.
Another variety of chrysanthemum—cinerariaefolium—is important as a natural source of insecticide. The pyrethrins extracted attack the nervous system of all insects. Harmful to fish it should be used with caution, but it’s not persistent in the environment and is biodegradable.
Grown for years to flower only in late summer and fall, they are short day plants, setting buds when they receive light for 10 hours and darkness for the other 14 hours of the day. This is why mums bloom in the spring on leggy stems if they are not cut back. And this is how growers manipulate their blooming, adjusting the dark and light periods with shades in the greenhouse so buds will form in any month. They’re nearly constantly available in grocery stores in every season. Mums grown for florists in greenhouses, however, produce few underground runners which mums need to survive the winter so they won’t come back.
At this time of year when garden mums abound, pick a plant with lots of buds. They bloom only once and won’t set more flowers until next year. Those buds, though, last a long time if you don’t let them dry out. They’ll revive if they do dry out but the flower buds won’t last as long or look as bright. Although mums are somewhat drought tolerant once established you should water deeply once or twice a week depending on the weather.
The specific type of plant doesn’t matter since they all have long term growth potential. If you particularly like one color or form of chrysanthemum, plant it now to enjoy again next year. You never know what the growers might decide to grow next season. Newly transplanted mums should get a high phosphorus fertilizer to stimulate root growth.
Choose a well-drained, sunny spot to plant them. Like many members of the aster family, mums won’t tolerate soggy ground. After blooming, trim off the old flowers and cut back plants to within 4 or 5 inches of the ground. If you started with 4-inch pots, trim back by half.
Next spring pinch them back when they are 8 inches tall around Memorial Day. Pinch again in July, then allow plants to start forming buds for the traditional fall show.
A word of caution: all parts of chrysanthemum plants are potentially toxic to dogs, cats, humans and other mammals and a skin irritant for some people. They aren’t generally eaten by deer, but a really hungry deer will eat anything. Spray with a deer repellent to make them even less likely to be munched on.
Jan Nelson, a landscape designer and California-certified nursery professional, will answer questions about gardening in the Santa Cruz Mountains. Email her at [email protected], or visit jannelsonlandscapedesign.com.
