Neil Anderson

Chrysanthemums punctuate fall gardens with starbursts in a rainbow of hues. Thanks largely to the efforts of the University of Minnesota, today's mums are bred to adapt to a variety of growing habitats with several varietals and series developed specifically for our northland extremes. Long sold as annuals, recent advances in hardiness have made them true perennials up to Zone 3.

Garden mums, which come in shapes ranging from common cushions to spiky surprises, are classified by the pattern of their florets, or petals. In addition to the familiar daisy type are the"decoratives" (semi-double or double), long-petaled "spiders," huge "football" blooms, quill (tube-like petals), and spoon (quills flatted at the ends). Mums are categorized by blooming season-early, mid-season, or late. In the Twin Cities, early mums can bloom in August, while "lates" begin in late September or October.

Early cultivated mums were the ancestors of today's upright mums, including the elaborate "show" mums -upright stalks topped with blooms. The now-familiar cushion-growing habit-plants covered all over with smaller blooms-was actually a product of the University of Minnesota's almost 80-year breeding program. Introduced in the 1950s, this Minn series "took the market by storm because it had more flower power," says Neil O. Anderson, associate professor of flower breeding and genetics at the university's horticultural science department. "Minnautumn," a spreading, reddish bronze, mid-season bloomer, has been one series standout over the years.

Considered a national leader in mum breeding, the U of M has produced

My Favorite 'Autumn Red' mum, featuring U of M maroon and gold

a number of breakthroughs. Among them are the low maintenance My Favorite series with frost-tolerant blooms. The plants grow to a huge hedge-up to 4 feet high and 3 to 7 feet in diameter-by the second year. The My Favorite 'Autumn Red,' with its maroon, daisy-type blossoms, has been a popular selection. Dr. Anderson's current mum project (he's working on lilies and gladiolus, too) is development of a hardy prostrate or "creeping" mum suitable for rock gardens and containers.

In their efforts to improve hardiness, Anderson and his colleagues have found that a higher number of rhizomes (underground stems that produce shoots and roots) correlates with better winter hardiness. Another advance that benefited northern growers was development of "day-neutral" varieties that depend on plant size, rather than day length, to trigger blooming.

Though fall is the traditional time to purchase mum plants, many gardeners now buy them for spring planting. Earlier is better for establishing perennials, says Mike Donahue, co-owner of Faribault Growers, a wholesaler that produces about a hundred varieties of "Mums from Minnesota," now available to consumers through the nursery's retail catalog.

Many cultivars of hardy mums planted in the early fall can survive the winter, especially if mulched to cover crowns, says Dr. Anderson. Look for plants with dark green foliage. October is probably too late to plant this year, but it's not too early to start planning for next year.

Mums need well-drained soil and sun-they'll get leggy and weak in the shade. Donahue suggests cutting back new spring-blooming plants by about half, pinching tips of existing mums

Sesquicentennial Sun mum

before the Fourth of July, and feeding in early summer to strengthen the plant for fall flowering. It's a good idea to mulch for winter, in case of sparse snowfall, and leave dead stems standing to collect snow, removing them come spring.

To be sure of obtaining hardy (perennial) mums, select plants by their varietal names-other mums should be used as annuals for a burst of late color. Beyond the Minn and My Favorite series, other hardy stars produced by the University of Minnesota are 'Peach Centerpiece,' 4-inch single quill blooms with a yellow center; 'Rose Blush,' an early upright; and 'Sesquicentennial Sun,' a new long-flowering yellow double. Thanks to the ongoing efforts of the university's horticultural department, northern gardeners can be sure that mums are here to stay.

For more information:
Catalog of "Mums from Minnesota" from Faribault Growers, 507-334-6220

U of M Extension Service fact sheet, "Garden Chrysanthemums," www.extension.umn.edu/distribution/horticulture/DG7068.html

Written by Alicia L. Conroy
Photos from the Minnesota Agricultural Experiment Station
Reprinted with permission from Midwest Home magazine, Minneapolis, MN. First appeared in Midwest Home October/November 2005.

Neil Anderson's faculty profile http://horticulture.coafes.umn.edu/Neil_O__Anderson.html

U of M hardy mum photo gallery
www.maes.umn.edu/MNHardy/components/mums.asp