University of Illinois Extension
Bruce Spangeberg

These articles are written to apply to the northeastern corner of Illinois. Problems and timing may not apply outside of this area.

Stateline Yard & Garden

Keeping Poinsettias Festive

December 6, 2001

Poinsettias are a featured live plant for the holiday season. Since they are living plants and growing conditions in the home or office are sometimes less than ideal, poinsettias need some sound care to keep looking festive. Here is my annual column of guidelines to keep your poinsettia healthy for the holidays.

While the colored foil often wrapped around the poinsettia pot may be decorative, keep in mind "drowning" of roots is a common problem. Either remove this wrap or place some holes in it so water can escape so plants do not sit in water and roots have adequate oxygen. To help avoid overwatering poinsettias wait until the soil surface begins to dry slightly before watering again. Don't let the soil completely dry out and become hard, however.

Fluctuating temperatures around the plant are another major concern. An optimum temperature range would be 60–68°F; temperatures above 75°F can cause decline. Keep the plant out of warm drafts, such as from heat ducts or radiators. Likewise, don't put the poinsettia near an entrance where it will constantly get a cold draft. Another related problem is excessively dry air.

Showy "flowers" of the poinsettia are actually modified leaves called bracts. The true flowers are actually found inside the colored bracts and are yellow in color. For a poinsettia to develop the colored bracts, the plant needs to have long nights. The critical daylength is actually 12 1/4 hours. If longer, only vegetative growth will occur. If shorter, the plant will begin to develop flower buds and colored bracts.

For many years, the poinsettia was considered to be poisonous. Extensive tests have proven this to be false. However, as with most plants, a child or pet could still have stomach distress if they were to eat poinsettias.

Poinsettias were cultivated by the Aztecs in Mexico, and are believed to be native to present day Taxco. Joel Robert Poinsett, United States Ambassador to Mexico, found the plant on hillsides of Taxco in 1825. He was the first to bring the plant to the United States that same year. Extensive cultivation and breeding starting in the early 1900's has led to the wide variety of poinsettias available today. In addition to the ever-popular red, poinsettias are also available in white, pink, and variegated pink and white varieties.

 

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