Prized for blooms that appear when other blooms are fading, chrysanthemums, natives of Asia, are grown since at least 500 A.D.. Previously, 160 species existed, but a lot of them have been moved into Dendranthema or other genera. Only in the new millennium have breeders concentrated on enhancing mums for the home garden, rather than only for the floral industry. Recommended for U.S. Department of Agriculture plant hardiness zones 5 to 9, chrysanthemums may also be grown as annuals.
Types and Sizes of Flowers
Chrysanthemum flowers come in four main shapes, sizes that range from less than 1 inch in diameter to over 3 inches and every shade except blue. The biggest blossoms are usually spider types composed of many long, curled tendrils. Decorative or florists’ mums show a mass of overlapping little petals, often encircling a domed center. As their name implies, daisy types form a ring of sole petals around a prominent center. The smallest mums, called pompons or buttons, are balls of petals which might be no larger than a nickel. Purplish-pink “Sweet Peg” sports 3/4-inch semi-double blossoms in October, while “J.C. Weigelan” bursts from 3 1/2-inch magenta, single blooms the exact same month. The uncommon “Will’s Amazing” produces 1-inch, bi-color, daisy type flowers that start out mainly red with a bit of creamy yellow near the center but end as predominately yellow with reddish tips.
Low-Growing Mums
As chrysanthemum blossom types vary considerably, so does the height of garden mother plants. Reportedly, they can range from under a foot to 6 feet tall. Low-growing (up to 18 ins) hardy mother plants are less prevalent than taller varieties but have the advantage of not needing support. C. weyrichii “Pink Bomb,” a good rock garden plant, forms a mat 12 to 18 inches high. Perhaps the lowest of all the Pacific chrysanthemum (C. pacificum) remains at 4 to 6 inches tall and functions like a weed-repelling ground cover. Its golden-yellow blossoms, only 3/4-inch wide, come late, in November.
Tall Garden Mums
Cultivars that climb to over 3 feet offer variety in plantings of chrysanthemums and can be put in the back of beds. If they get lanky, you might need to link them to stakes for support. “Emperor of China,” will reach 4 feet and produces beautiful two-tone pink blossoms late in the autumn. “Mei-kyo,” a good companion for “Emperor of China,” is a 3-foot plant which resembles a little shrub if not pinched back. Big plants don’t always bear huge blossoms, though, as these two have 1 1/2-inch and 1-inch blooms, respectively. If you want larger blooms, remove all flower buds but one or two in every cluster.
Growing Tips
Perennial garden mums are photoperiodic, thriving in reaction to shortening days and longer nights. When nighttime approach 12 hours in length, buds begin to form. September and October are the peak months for chrysanthemum blooms in the backyard. Consistently plant mums at least 20 feet apart from streetlights or other lights which burn at night or the plants might be thrown off schedule and fail to blossom. Water deeply and regularly and mulch to maintain moisture. Evergreen boughs serve nicely as a mulch for chrysanthemums. Their ideal soil pH is slightly acidic, between 5.8 and 6.8. Dig in organic matter that’s on the acidic side, like peat moss, bark, leaves and sawdust. Begin pinching mums back in the spring when new shoots are 3 to 4 inches long. Grasp the growing tip and initial pair of leaves and nip them off with your thumb and forefinger. Repeat several times until early July to encourage denser foliage and more blooms.