Red poinsettias are the traditional Christmas flower in the United States and throughout much of the world. Poinsettias (poin-set-ie-uhs) provide a cheerful Christmas spirit and their bright color goes well with the Christmas tree and other decorations in the home and office. White, pink and marbled colored plants are also available although not as popular as the red varieties.
The showy, colored parts of the plant, commonly called flowers, are actually modified leaves or bracts. The inconspicuous true flowers are located in the center of each whorl of bracts. They are green, have no petals and bloom with yellow flower parts and pollen.
Winter Care in the Home
Place your poinsettia in a sunny window or the bright- est area of the room but don’t let it touch cold window panes. The day temperatures should be 65° to 75°F and 60° to 65°F at night. Do not place on top of a TV set because it gets too warm while it is operating. Tempera- tures above 75°F shorten bloom life and below 60°F cause root rot. Move plants away from windows at night or draw drapes between them.
Examine the potting soil daily. Never let the plant wilt or it will lose its leaves. When the soil becomes dry to the touch, water the plant with lukewarm water until some water runs out of the drainage hole, then discard the drainage water. Poinsettias do not like “wet feet.” Repotting is not necessary during the winter.
Spring Care in the Home
Most dealers only sell the better varieties of the new long lasting flower types. Many of these plants hold their blooms until May when they can be cut back and set outdoors after frost.
As days lengthen and light intensity increases in March, side shoots often develop below the bracts. The old leaves
and stems can be removed above this new growth. If the old leaves have fallen and the bracts have faded, the old stems may be cut to 6 inches above the soil.
The plants may also be repotted at this time with a commercial potting soil or a mixture of 1 part soil, 1 part sphagnum peat and 1 part sand. If the plants were grown single stem (nonbranched with several plants per pot), it is best to discard them. These cultivars do not branch very well and will not form attractive plants the second year. Reduce watering frequency in proportion to the amount of foliage removed from the plant.
Poinsettias can be grown indoors as foliage plants in summer or moved outside, whichever is convenient.
Summer Care Outdoors
When frost danger ends in May poinsettias may be grown outdoors. Choose a wind protected, sunny location with some protection from midday and afternoon sun. Sink the pot to the rim in a well-drained soil. Rotate the pot every two weeks to break off the roots growing out of the drainage hole. Fertilize monthly according to direc- tions with a houseplant fertilizer. Check water needs frequently because the soil can dry out quickly in summer.
Between May 15 and August 1, cut off the tips of the plants occasionally to get a shorter, bushier plant with more branches.
Fall Care and Reblooming in the Home
Bring the plant indoors September 1 and place near the sunniest window. Beginning October 1, the plant must receive 14 consecutive hours of uninterrupted darkness each night but it must also get bright light during the day. Poinsettias bloom naturally by Christmas if exposed to the normal period of darkness and daylight after October 1, provided the dark period is not interrupted by turning on
KANSAS STATE UNIVERSITY AGRICULTURAL EXPERIMENT STATION AND COOPERATIVE EXTENSION SERVICE
the room lights at night. Street lights shining through room windows may also delay bloom.
If the room is used at night, protect the plant from light by placing it in an unused closet or by covering with a cardboard box (tape the seams) from 5:30 every evening until 7:30 the next morning. The night temperature during the dark period must be between 60° to 65°F while flower buds are being formed, or bud set may be delayed or terminated.
Plants must receive bright sunlight during the day for good color to develop. An artificial light source is often required to supplement low fall and winter sunlight. Fertilize every other week and keep the soil from becom- ing too dry. Plants need extra nourishment while being forced into bloom.
After the bracts show full color, usually by Thanksgiv- ing, the dark treatment is no longer necessary. The key ingredient to producing a quality plant is good light during the day, which is often lacking in homes and offices, and 14 hours of total darkness during bud set. If the plant does not suit your standards, greenhouse-grown plants are on the market by this time.
Summary of Poinsettia Care
* During winter, place plants in brightest area of the home.
* In summer, some protection is needed from direct midday and afternoon sun.
* Day temperature should be 65° to 75°F
* Night temperature should be 60° to 65°F.
* Protect from drafts of hot or cold air.
* Move plants away from windows during winter
* Keep soil moist but not soggy wet.
* Water when soil becomes dry to the touch. * Do not let the plant wilt.
* Use lukewarm water.
* Discard drainage water.
* Fertilize monthly with houseplant fertilizer. * Prune plants in spring and summer.
* Bring plants inside by September 1.
* Begin dark treatment October 1.
About the authors:
History of Poinsettias
Poinsettias have a fascinating history and tradition. Poinsettias are actually woody shrubs native to Taxco, Mexico where they grow wild outdoors to a height of 10 feet. The Aztec Indians of Mexico cultivated and regarded them as a symbol of purity before Christianity came to the western hemisphere. They also made a reddish purple dye from the bracts and used the milky latex sap to counteract fever.
Franciscan priests settled near Taxco during the 17th century and began to use the flower in their nativity processions because of its appropriate holiday color and blooming time.
Poinsettias were introduced into the United States in 1825 by Joel Robert Poinsett. While serving as the first United States ambassador to Mexico, he discovered the wild poinsettias growing on the hillsides near Taxco. Poinsett sent plants to his home greenhouses in Greenville, South Carolina, and began giving plants to botanical gardens and horticultural friends. A nurseryman friend in Philadelphia started the first commercial propagation and sales from some of Poinsett’s plants. These wild plants lasted only a few days in the home.
The poinsettia industry was pioneered and developed by the Ecke family of California in the early part of this century. During the mid-50s plant breeding research was started and led to many of our current improved varieties (cultivars). T oday’ s poinsettia is a free-branching hybrid plant with larger, longer-lasting bracts.
Selecting Your Poinsettia
Choose plants that have clean, healthy, dark green leaves and colorful bracts. Be sure to check the underside of the leaves for insects. Avoid plants with missing leaves or bruised, broken or spray-damaged leaves. Plants shedding yellow pollen are overmature. Healthy plants last longer and are worth the extra price.
On a cold day (below 40°F) wrap the plant and pot in paper for the trip home and purchase at the end of the shopping trip. Even a slight chill or draft can cause the leaves to drop later. Unwrap the plant as soon as you get home and place it in bright light away from cold or hot air drafts. Pierce the foil at the bottom of the pot for drainage. Water with lukewarm water if the soil is dry.
Alan B. Stevens is an Extension Specialist, Floriculture and Ornamen