A Time to Keep Your Poinsettia in the Dark

The poinsettia is a short-day or long-night plant; without long nights, these plants will continue to grow and produce leaves but will never flower. Short periods of light, and even the glare from a nearby streetlight will prevent theses plants from flowering. Once you see the flowers developing and the bracts (which are the red parts of the plant often assumed to be flower petals) start showing color, it is not as important to maintain complete, uninterrupted dark periods, but should be continued until the bracts are almost fully expanded. Reduce fertilizer once the plant is brought into the home and less sunlight is available.

WPC's Community Conservation Staff offer the following tips for growing and maintaining a healthy poinsettia.

1. February to March: cut back each of the old flowering stems to 4-6 inches;
2. Re-pot into a larger pot (2-3 inches larger by diameter);
3. When night temperatures are above 60° F, place plant outdoors in a shady location for 2-3 weeks of acclimation, then place pot in the ground in a sunny protected garden. (Light shade in the afternoon is OK.)
4. Turn pot regularly;
5. For short bushy plant with lots of flowers, pinch the growing shoots every 3-4 weeks;
6. Keep plant actively growing all summer; water and fertilize every 2 weeks with a soluble fertilizer (20-20-20);
7. Bring poinsettia indoors when temperatures fall below 55°F. Put in a sunny location such as a south window;
8. In late September, early October, plants must be in total darkness for more than 12 hours a night (5 p.m. until 8 a.m.). During the day give the plant as much sunlight as possible;
9. Flowers mature in 60- 85 days, about 10 weeks from putting the plant in darkness.

E-mail Today's WPC Daily to a Friend!

Become a Western Pennsylvania Conservancy Member

View the winning WPC Daily