The poinsettia was first found in Mexico in the 1800s, growing as a wildflower. It has since become the most popular living Christmas gift in the United States.
The large, white, pink, red, yellow, lime green, or bicolor flowers are actually groups of bracts that surround a small, inconspicuous true flower. Ranging in height from 1 to 3 feet, the plants produce blossoms that are 6 to 12 inches wide.
With proper care these plants will continue to bloom for several months, and some can be made to blossom the following season. While blooming, the plants simply need plenty of sunlight and protection from drafts and sudden changes in temperature. Reduce water during the rest period from spring to midsummer, then increase waterings and apply fertilizer every 2 weeks. These plants normally flower in the fall, when the nights are long. Beginning about October 1, they need 2 weeks of long (14-hour) nights, uninterrupted by any light, before flowers are initiated. If your plant is indoors, be sure that household lights do not interrupt this darkness. You may have to place the plant in a dark closet at night or put it outdoors in a protected spot.
Light: Place in a bright, indirectly lit south, east, or west window.
Water: Keep evenly moist. Water thoroughly and discard drainage.
Humidity: Average indoor humidity levels.
Temperatures: 50° to 55° F at night, 65° to 70° F during the day.
Fertilization: Fertilize when actively growing
Propagation: Take cuttings from stems or shoots before they have hardened or matured.
Grooming: Prune after flowering. Pinch back stem tips of young or regrowing plants to improve form. Be careful not to remove flower buds when pruning.
Repotting: Repot infrequently in winter or early spring when needed.
Problems: If soil is too wet or too dry, or if a plant is suddenly moved to a post where light is low, weaves will drop. Poor drainage, overwatering, or standing in water will cause root rot.