HO-73
YARD AND GARDEN
THE POINSETTIA
John A. Wott
HORTICULTURE DEPARTMENT COOPERATIVE EXTENSION SERVICE PURDUE UNIVERSITY LAFAYETTE INDIANA 47907
The poinsettia (Euphorbia pulcherrima) is the most popular Christmas season plant. It was introduced into the United States in the late 1820’s from its native Mexico by our first ambassador to that country, Joel Robert Poinsett. The plant was first known and probably is still best known for the bright red leaves or bracts which surround the inconspicuous small yellow flowers. Today, poinsettias may be purchased in colors ranging from white and cream through the various shades of pink and red.

Poisonous principle
The poinsettia has long been veiled in an aura of folklore and ignorance and has gained a reputation as a highly toxic and deadly plant. A member of the spurge family, it is closely related to the dangerous Snow-on-the Mountain. In recent tests at The Ohio State University, Albino Wistar rats showed no signs of toxicity or any apparent ill effects when given large doses of homogenates made from the leaves, bracts or flowers of the poinsettia. The force-fed rats also showed no changes in dietary intake or general behavior pattern. Thus, the poinsettia is not the dangerous plant, as many people still believe.
Purchasing
Poinsettias are priced according to the number of blooms; those with more blooms are more expensive. For the best buy, look for plants with bright green foliage all along the stem. Plants with healthy foliage should have good root systems and should last well in your home where growing conditions are usually not ideal for poinsettias.
Select plants with the least amount of pollen showing on the fresh true flowers situated just above the colorful bracts. Plants with old flowers tend to drop their bracts sooner. Differences in varieties do occur, and many cultivars will hold their bracts for several weeks or even months after the true flowers have dropped.
Most plants are sold as three single stem plants per pot. However, today with the new varieties it is possible to have multi-stemmed plants. Thus, each plant may have two to four branches and flowers. Flowering and bract formation occur evenly and these plants are equally as good as single-stemmed plants.
Avoid bruising or chilling the plant as you bring it home from the florist shop. Sudden drops in temperature to 50°F. or below will often cause wilting followed by dropping of the bracts.

Home care
Proper care of poinsettias will keep your plant looking attractive for a long time. The conditions inside our northern homes often are not ideal for poinsettias, natives of the tropics. Under unfavorable conditions, the leaves will yellow and drop off, and the bracts may also soon drop.
The poinsettia is grown in the greenhouse at temperatures of 60-70°F., with a high relative humidity and maximum sunlight. As much as possible, homeowners should try to simulate these conditions for best home care.
Root rot disease is more prevalent when the plants are kept below 60°F. Plants kept in rooms where the temperature is above 70°F. will usually have a slightly shorter life.