Ways to develop a colorful poinsettias to re-bloom
Fertilize your plant every two weeks after the blooming season with a balanced, all-purpose fertilizer. Continue through August.
By March or early April, when the colored bracts begin to turn or fall, cut the plant back, leaving 4 to 6 buds.
Re-pot into a slightly larger container (2-3 inches larger in diameter).
Keep the plant indoors near (not directly in) a sunny window or outdoors in a morning sun-afternoon shade location. Water and fertilize regularly, and by the end of May you should see vigorous new growth.
Make sure to turn the plant so that the new growth grows evenly on all sides.
If you have been growing them outdoors in the summer, when fall comes bring your poinsettia indoors to a sunny location before night temperatures fall below 55-60°F at night. Check for pests and diseases and place the poinsettia in a south window.
Poinsettias begin to set buds and produce flowers as the nights become longer.
Beginning October 1, keep your plants in complete darkness for 14 continuous hours each night by moving it into a dark room or placing a large box over it.
During the day, allow 6-8 hours of bright sunlight. Flowers should mature in 60-85 days.
Continue this for 8-10 weeks, and your poinsettias should develop a colorful display of holiday blooms!