For Release August 25, 1998

Plan Ahead for Christmas Poinsettias

AGRI-VIEWS
by Chuck Otte, County Extension Agent

It’s the end of August and the Christmas season seems to be a long time away, but it will be here before you know it. When you think Christmas you just have to think Christmas trees and poinsettias. Those poinsettias are originally a semitropical perennial shrub from Mexico. To get one to bloom takes literally months of advanced planning. Many of us, myself included, just go purchase a new poinsettia every year, and when the season is over and the leaves have fallen, I just throw it in the compost bin. But some of you are obviously more dedicated gardeners than I. Or maybe you have better windows to grow plants in in the wintertime.

The bright red, pink and white of the poinsettia are not the actual flowers. These large "petals" are modified leaves or bracts. The true flowers are rather inconspicuous and are located in the middle of the whorl of bracts. They are green, have no petals and when in bloom have yellow flower parts and pollen.

If you have kept your poinsettia from last year (or previous years) and want to enjoy the colors of Christmas then it’s time to get started. To get the poinsettia plant to bloom requires a very strict regimen of light and dark. Many people think it’s the amount of light that the plant receives that makes it bloom. Actually it’s the amount of darkness that the plant experiences that makes it bloom. The "old-fashioned" poinsettias were very sensitive to length of night and how dark it had to be. Many of the newer varieties are not nearly as sensitive, but you can’t be sure what kind you have so you need to assume it is very sensitive.

September 1st bring your poinsettia inside (if it’s been outside) and place near the sunniest window you have. At this point you shouldn’t do any more trimming or fertilizing. Don’t let the plant get too dry, but don’t drown it either. Make sure your potting soil has good drainage and that excess water can drain out the bottom. Two critical problems are over and under watering. If the plant wilts from under watering leaves and blooms are liable to fall off. If the soil stays consistently saturated root rot will set in and kill the plant. Water when the soil surface feels dry to the touch.

Starting October 1, the plant must receive 14 hours of uninterrupted darkness each night. Probably the best way to do this is to get a large box and set over it every night. But the plant must also get bright light during the daytime. If the daytime light is limited you will have to supplement with artificial light. Tape all the seams shut to make sure it is completely dark. It is also important to have the temperature between 60 and 65 degrees during the night to make sure flower buds are formed properly and not delayed or terminated. Once you’ve started the dark treatment fertilize lightly every other week. After the bracts show full color, usually around Thanksgiving, then the dark treatment should no longer be necessary. The two most important elements are the bright light during the day and good, uninterrupted dark.

To maximize the life of the colorful bracts follow these guidelines (which hold for plants you purchase each year also.) Place in a bright part of the house. Day time temperature should be 65 to 75, night time 60 to 65 degrees. Protect from cold drafts (avoid doors and drafty windows) and don’t place where it will get excessively warm also (avoid the tops of televisions or near a furnace vent.) Do not let the plant wilt and water when the soil is dry to the touch. Use lukewarm water to water the plant and discard drainage water. You will probably have to poke holes in the decorative foil the plants often come wrapped in and place a saucer under it. Christmas will be here before you know it and if you want to make your own poinsettia bloom, start now! For more information stop by the Extension Office, 119 East 9th, and pick up our bulletin on poinsettias.

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