Flowering houseplants associated with the Christmas season include the poinsettia, Christmas cactus, amaryllis, and cyclamen. After the holidays, the fate of these plants becomes a dilemma for some people. All can be kept to bloom again another year. The Christmas cactus, for example, is an easy to grow plant, which can be kept for many years. Others are best discarded.
If given proper care in the home, poinsettias should retain their colorful bracts for 2 or 3 months. Toss the poinsettia when you grow tired of it or it becomes unattractive.
For those home gardeners who enjoy a challenge, it is possible to get the poinsettia to bloom again next season. Cut the stems back to 4 to 6 inches above the soil when new sideshoots develop below the bracts or when the bracts fade in March or April. The poinsettia may also be repotted at this time. When new growth appears, place the poinsettia in a sunny window with temperatures of 65 to 75 F. Water the plant when the soil surface becomes dry to the touch and fertilize every 2 weeks with a houseplant fertilizer.
In late May, move the poinsettia outdoors. Harden or acclimate the plant to the outdoors by placing it in a shady, protected area for 2 to 3 days, then gradually expose it to longer periods of direct sun. Once hardened, dig a hole in an area that receives 4 to 6 hours of sunlight (preferably morning sun and afternoon shade) and set the pot into the ground. To obtain a compact, bushy plant, pinch or cut off the shoot tips once or twice from late June to mid-August. Continue to water and fertilize the plant outdoors.
The poinsettia should be brought indoors in mid-September. Place the plant in a bright, sunny window. The poinsettia is a short-day plant. Short-day plants grow vegetatively during the long days of summer and produce flowers when days become shorter in the fall. To get the poinsettia to flower for Christmas, the plant must receive complete darkness from 5:00 p.m. to 8:00 am daily from early October until the bracts develop good color, usually early to mid-December. Protect the plant from light by placing it in a closet or by covering with a box. During the remainder of the day, the poinsettia should be in a sunny window.
Holiday cacti include the Christmas cactus, Thanksgiving cactus, and numerous hybrids. After flowering, place plants in a cool area (60 to 65 F) and water sparingly. Water the plants more frequently during their active growth period from spring through summer. Also, fertilize holiday cacti approximately once a month during the growing season. Flowering of holiday cacti is controlled by temperature and day length. In the fall, place plants in a cool location (60 to 65 F) that receives only natural daylight. Flower initiation will occur under these conditions and plants will bloom sometime between late October and January.
Amaryllis bulbs are often given as Christmas gifts. While many people discard the amaryllis after flowering, it is possible to get the bulb to bloom yearly.
After the flowers fade, cut off the flower stalk with a sharp knife. Make the cut 1 to 2 inches above the bulb. Don't harm the foliage. In order for the bulb to bloom again next season, the plant must replenish its depleted food reserves. The long, strap-like leaves manufacture food, which is stored in the bulb. Place the plant in a sunny window and water when the soil surface becomes dry. Fertilize every 2 to 4 weeks with a houseplant fertilizer.
The amaryllis can be moved outdoors in late May or early June. Harden or acclimate the plant outdoors for a few days. Once hardened, dig a hole in an area that receives partial to full sun and set the pot into the ground. Outdoors, continue to water the amaryllis during dry weather. Also, continue to fertilize the amaryllis once or twice a month through July. Bring the plant indoors in mid- to late September. Plants left indoors should remain in a sunny window.
Amaryllis bulbs need to rest before blooming. To induce dormancy, place the amaryllis in a cool, semi-dark location and stop watering the plant in late September/early October. Cut off the foliage when the leaves dry and turn brown. Then place the pot in a dry location with a temperature of 45 to 55 F and allow the bulb to rest for 2 to 3 months. The length of the rest period for amaryllis bulbs varies. After several weeks of rest, periodically check the bulbs for signs of new growth. When a bud or foliage appears, place the amaryllis in a warm, bright location and water to start the growth cycle again. If repotting is necessary, do so before watering.
Like the poinsettia, the cyclamen is best discarded after flowering. However, it is possible to get the plant to reflower.
After the cyclamen has stopped blooming, gradually withhold water. Remove the foliage after it has died back and then store the pot in a cool (45 to 50 F), dark area for 3 to 4 months. In late summer, provide warmer temperatures and begin watering to encourage new growth. If repotting is necessary, replant the tuber into fresh potting soil at the end of the rest period. The top of the tuber should be slightly above the soil surface. The cyclamen needs cool temperatures (50 to 65 F), high humidity, and bright light for maximum growth and bloom.
This article originally appeared in the December 6, 2002 issue, pp. 131-132.