Fall Color - Chrysanthemums
You know fall is approaching when the mums appear in the local nurseries. This classic fall bloomer has been a symbol of the season for almost as long as we have been a nation.
Wild chrysanthemums are native to Asia and northern Europe. They were first domesticated in China 15 centuries before CE. It is unknown how long there was a breeding program, but by 1630 there were over 500 recognized cultivars. The domesticated chrysanthemum was introduced to Japan in the 8th century AD where it became the symbol of the emperor. Chrysanthemums reached our own shores from England in 1798 brought here by a Colonel John Stevens.
Although we have a preference for autumnal hues, chrysanthemum flowers come in every color except blue. The blossoms range in shape from daisy to tightly compact pompoms and buttons to more loosely arranged petals and spikes. The plants themselves are divided into two types, the hardy mums that we grow in our gardens and the exhibition type with their exaggerated flowers and forms such as standards (trees), topiary and bonsai.
Chrysanthemums are photoperiodic meaning that the length of the day determines when they bloom. When the nights reach ten hours long, they begin to produce buds. Within 6 to 8 weeks, they will start to bloom.
Mums like the cooler weather of fall. Lower temperatures result in more intense flower color and longer lasting flowers until a hard frost kills the plant (but not the roots).
Hardy mums are hardy in growing zones 3 through 9. Most people grow them as annuals, purchasing budded plants in containers in the fall and then discarding them after the first hard frost. With a little care, mums can be grown as a perennial in your garden to return year after year.
Mums will grow in part shade, but prefer full sun. If you want the maximum number of flowers on your mums, grow them in full sun which is defined as 6 to 8 hours of sun each day. They prefer a more alkaline soil and it must be well-drained. They are also heavy feeders, so be prepared to fertilize them several times throughout the growing season. Water regularly. Mums have shallow roots and can dry out quickly.
After the first killing frost, resist the urge to remove the dead vegetation from your plants. As ugly as it is, leave it in your garden throughout the winter and you will be rewarded with new growth, i.e. new plants in the spring at which time you can finally get rid of the ugly dead foliage. If your winter is cold and snowless, it's a good idea to mulch around your plants. Mums have very shallow roots which can heave up out of the ground during the winter freeze/thaw cycles. If this happens, simply push the heaved rootball back into the soil. You can even do it by lightly stepping on it.
Like your other perennials, mums should be divided every three to four years. Division is best done in the spring so that the resulting plants with have time to develop their root system before they devote their energy to making flowers in the fall.
Chrysanthemums can be grown from cuttings from existing plants. Make your cutting at least 4 inches long, making sure that it has leaves. Place the cutting in a soilless mix and keep it outdoors in a sunny spot until it develops roots at which time you can transplant it into a small container filled with regular potting soil. Fertilize it every week for two or three weeks, then plant it directly into your garden. It should flower in the fall.
Mums can also be grown from seed. Start your seeds indoors 6 to 8 weeks before your last frost. Don't forget to harden them off before planting them out in your garden.
To achieve the densely flowering plants that you see for sale in the fall, you will need to "pinch" your plants. Pinching means cutting off the growing tips of each branch which will force the plant to grow more branches. More branches means more flowers. You can start pinching your plants when they reach a height of 6 inches for the larger varieties, 4 to 5 inches for smaller varieties. Pinch them every 3 to 4 weeks until the Fourth of July.
© 2014 Caren White