Garden Guide

Poinsettias — colorful addition to the holiday season
Dec. 11, 2013 @ 04:58 AM

Poinsettias are perhaps the most recognizable holiday flower. Understandably, the poinsettia is the most popular flowering plant in the United States, with over 70 million sold annually.

The poinsettia is native to the tropical areas of southern Mexico and Central America, where it grows as a small tree. Joel Poinsett, the first U.S. ambassador to Mexico, was captured by the beautiful red blooms in December and introduced the poinsettia to the United States. The name poinsettia is derived from his name.   

There are over 100 cultivars of poinsettia to choose from. The bracts are the showy part of the plant, which are often mistaken for the flowers. Look closely though and you will see the yellow cyathia, the true flowers, at the center of the bracts. Bracts can range in color from red, pink, white, salmon, to bicolors, and speckles! Contrary to popular belief, poinsettias are not poisonous; however, like all ornamental plants, they are not meant for human or animal consumption. The milky sap that is exuded when leaves are broken can cause skin irritation for those with sensitive skin.

Choose plants with brightly colored bracts and dark green foliage. Try to avoid plants with green around the bract edges. Also, look for plants that are balanced and attractive from all sides.   

Be very careful not to expose poinsettias to temperatures below 50 degrees! When you transport your plant home, do not place it in the trunk. Also, be careful that the leaves and bracts do not touch a cold window when placed at home. Cold temperatures will cause chilling injury and result in unattractive or dead plants.

Once at home, place the poinsettia in indirect, natural light (at least 6 hours). Be sure to keep the soil moist, but not soggy. If the container is wrapped in decorative foil, punch drainage holes into the foil to let water escape. Do not let the soil dry out either. The optimal temperature for poinsettias is between 70 and 75 degrees; however, lowering nighttime temperatures into the 60s will help maintain bract coloration.   

After the holiday season is over, you can compost the plant or keep it to rebloom next year. Treat the poinsettia as you would any houseplant; in addition, apply a half strength fertilizer monthly. After the last spring frost has passed, cut stems back to 3 to 4 inches and repot in a slightly larger container. Water thoroughly and place outside. While outside, fertilize with a complete fertilizer every 2 weeks, but pinch back if the poinsettia gets too large.

When fall frost starts to threaten plants, bring the poinsettia in. During the last week of September or early October, poinsettias need to be exposed to 13 hours of uninterrupted darkness daily to bloom. So, cover the plants with a box or place in a closet — just be sure that NO stray light hits the plant. Any light that reaches the plant during this time will delay flowering. Daytime temperatures should be in the low 70s and nighttime temperatures should be in the high 60s. Plants should bloom after 9 to 11 weeks of this treatment, depending on the cultivar.   

Poinsettias are a beautiful, colorful addition to the holiday season. Many local garden stores offer a wide range of stunning poinsettias, ready for you to take home today! For more information on poinsettias reference HIL 8508: Consumer Care of Poinsettias (http://www.ces.ncsu.edu/depts/hort/hil/pdf/hil-8508.pdf) or contact our Center at (919) 775-5624.

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