The colorful bracts of poinsettias may stay bright for months if you care for them properly. Bright, indirect light and frequent watering are essential. Don’t allow the plants to wilt, but watering too often can damage roots.
Poinsettias thrive on indirect, natural daylight — at least six hours a day. Avoid direct sunlight, as this may fade the bract color. If direct sun cannot be avoided, diffuse the light with a shade or sheer curtain. To prolong color, keep plants out of traffic areas and protect from cold drafts and excessive heat. Ideal temperatures are 67F to 70F during the day and 60F to 62F at night. Remove damaged or diseased leaves.
Poinsettias require moderately moist soil. Check plants daily and water thoroughly whenever the soil feels dry to the touch. Plants in clay pots require more water, while those in plastic pots are easily overwatered. Apply water until it runs out the drainage hole. However, do not allow poinsettias to sit in standing water. If the container is wrapped with foil, remove it when watering or make a hole in it for drainage. Discard any collected water in the drainage receptacle.
A poinsettia does not require fertilization while it is in bloom. However, to maintain green foliage and promote new growth indoors after the holidays, apply a balanced all-purpose house plant fertilizer once per month. Always follow the directions on the fertilizer label.
Plants can be re-flowered, although the procedure is somewhat demanding. To re-flower, keep the plant indoors until the danger of frost has passed, then move it outdoors. Remove the bracts when they wither and discolor. Keep the plant in high indirect light (morning sun/afternoon shade). Water and fertilize often. Shape the plant as desired; prune it or pinch it to encourage branching. Bring the plant back indoors when night temperatures start to fall below 60 degrees. Continue to fertilize and water. Starting October 1, give the plant 14 hours of continuous darkness daily until bract color is well developed (mid-November). This can be done by placing the plant in a closet or covering it with a cardboard box. Any light during the dark period will delay or inhibit flowering. Night temperatures at this time should be between 60 and 70 degrees F. During the remaining 10 hours each day, give the plant maximum light.