University of Illinois Extension

 


Barbara Larson
Unit Educator, Horticulture
Boone and Winnebago counties

Past Issues

Want to know when a new issue comes out? Sign up for eNews

Poinsettias

Poinsettia is the most popular holiday flowering plant. The plant’s common name comes from Joel Poinsett, the first U.S. ambassador to Mexico, who introduced the plant to the U.S. in 1825.

In its native Guatemala and southern Mexico poinsettias are large shrubs or small trees. The showy "flowers" are actually a combination of bracts and cyathia. The bracts, which are modified leaves, appear to be colorful petals and the cyathia, which are the true flowers, create the yellow center.

In 1919 poinsettia was mistakenly labeled poisonous. The American Medical Association’s Handbook of Poisonous and Injurious Plants states eating poinsettia may cause occasional vomiting. Because poinsettia leaves are reported to be very bitter, most children and animals are discouraged from eating them. Poinsettias, as members of the Euphorbia family, produce a milky sap that may irritate the skin in some people.

For almost one hundred years the Ecke Poinsettia Ranch just north of San Diego has been the center of poinsettia breeding. Almost all the sizes and colors (pink, white, peach, yellow, freckled, or marbled) of poinsettias originated there.

When shopping for poinsettias look for a full robust plant with deep green leaves completely down the stem. Yellow or damaged leaves may indicate poor handling or a disease problem that will limit the life span of the plant. Check the plant from all sides. It should be well balanced with thick, stout stems.

Poinsettias rarely develop their full beauty in the home if bought early so look for mature plants. The bracts should be fully colored without green edges and lie horizontal. Little to no pollen should be seen on the yellow cyathia in the center.

After choosing the perfect plant protect it from the cold during the trip home with paper or plastic. Tropical poinsettias are easily injured by our cold weather this time of year.

In the home, position your poinsettia near a bright sunny window; east, south, or west exposures are the best. Do not let any plant parts touch the cold windowpane because the cold temperature will damage them.

Poinsettias prefer temperatures of 65 - 70°F. Higher temperatures will cause the leaves to yellow and fall, and the bracts to fade early. Temperatures below 50°F. will cause leaf drop. Keep poinsettias out of cold drafts and away from heating sources.

Check the soil surface daily. If the surface is dry, water the plant thoroughly. You’ll know you added enough when water comes out of the drainage holes at the bottom of the pot. If the pot is in a saucer or enclosed in decorative foil, always drain the excess water in the saucer or foil to prevent root rot. Do not allow the soil to dry out or the poinsettia will wilt and loose its leaves.

Poinsettias should not be fertilized while they are blooming.

With proper care and the right environment, the showy bracts of poinsettias should last several months.

After the bracts fade, many people discard the plant because it is difficult to get poinsettias to rebloom. If you’d like the challenge, after the bracts fade in March or April cut the plant back to 8 inches tall. Keep in it in a sunny window, water regularly, and fertilize every two weeks with a well balanced complete fertilizer like 10-10-10. If the plant gets leggy, pinch it back to 6 inches in height.

In late spring, repot into a larger container using a potting soil high in organic matter. After minimum night temperatures exceed 50°F move the poinsettia to a partially shaded site outdoors. Water and fertilize regularly. Keep the plants pinched back to two sets of leaves per stem. Do not pinch after the first of August.

Bring the poinsettia indoors before the first fall frost. Keep in a sunny window at room temperatures of 65 - 70°F. Fertilize every two weeks.

Poinsettias are short day plants meaning they need short day length and long nights to initiate flower buds. Beginning in late September, the plant must have complete darkness from 5 p.m. until 8 a.m. Cover the poinsettia with a light-tight box or put it in a closet every night until color shows in the bracts. During the day the plant must have bright light. Night temperatures above 70-75°F or light during the dark period will prevent or delay flowering.

The wide variety of sizes and colors in poinsettias make them perfect holiday decorations whether in the home or office. With care, your lovely plant should last through the winter and even brighten next year’s holidays.

 

Past Issues

Want to know when a new issue comes out? Sign up for eNews