Place the poinsettia in an area where it receives natural, indirect light. Keep the plant at 68 F during the day and slightly colder at night.
Place the plant in a saucer to protect furniture. Water the poinsettia when the soil begins to feel dry. Remove excess water from the saucer 10 minutes after watering the plant. Don't let the plant sit in water for long periods of time.
Water the plant until the middle of spring. Stop watering, and allow the stems to dry up. Cut the plant down to a few inches above the soil, and replant it in new soil. Fertilize when it begins to grow, and water thoroughly. In midsummer, move the plant outside to a shady location. In August, bring the plant back inside, and cut the stems back. Leave 3 to 4 leaves on each shoot. Place in a sunny spot and water regularly. In mid-autumn place the plant in complete darkness from 5 p.m. to 8 a.m. This causes the poinsettia to reflower.