BLUE SPRINGS, Mo. - The popular Christmastime plant, the poinsettia, is named after Joel Roberts Poinsett, the diplomat and botanist who in 1825 brought the plant to the U.S. from southern Mexico. These semi-tropical plants aren't ideally suited for Missouri's climate, but a University of Missouri Extension horticulture specialist has some tips for enjoying your poinsettia year-round.
"To maintain your poinsettia beyond the holiday season, you will need to give the plant TLC," said Lala Kumar.
The first step is to choose the right plant. "Select a plant with dark green foliage and brightly colored bracts," Kumar said. Bracts are the red, white or pink top leaves. They are often mistaken for flowers.
The true flowers, or cyathia, are small, inconspicuous button-like objects in the center of the bracts. Cyathia should be tightly clustered and shedding little or no pollen, she said. Leaves should be free of disease and insects, and the plant should be strong enough to stand on its own.
If the temperature outside is less than 50 degrees, ask for a protective sleeve to cover the plant before leaving the store. However, poinsettias should not remain sleeved any longer than necessary. Ethylene gas produced by the plant can accumulate within the sleeve, causing premature flower drop and leaf curling.
Place the plant where it will receive a maximum of indoor sunlight. Keep it away from drafts or rapid temperature fluctuations. Bracts will retain their color longer when the temperature is about 72 degrees during the day and about 60 degrees at night.
"Poinsettias do not like wet feet," Kumar said. "Water only when the surface of the growing medium is dry to the touch. Discard the water that might collect in a saucer placed under the pot. If the pot is foil-covered, make sure there is a drainage hole in the foil."
In May, cut the plant back to a height of 6 to 8 inches and place it in a shady spot outside. Keep the plant watered and fertilized. Prune the poinsettia in the summer to keep it busy.
For the plant to flower, the poinsettia will need about 13 hours of uninterrupted darkness each night, beginning around the fourth week of September, Kumar said. One way to do this is to keep the poinsettia in a dark closet every day from 5 p.m. until about 8 a.m. the next morning.
"Once color development is well under way, after approximately 10 weeks, this long-night treatment can be discontinued," Kumar said. Remember to keep the plant near a sunny window during the daytime.