Spring bulbs that are forced to flower in mid-winter are special attractions. A pot of flowering bulbs for Christmas or any other special occasion is a nice gift to give or receive. Forcing may not be the best term to describe the process. Manipulation, influencing, or coaxing may be better descriptions. In forcing bulbs, you’re stimulating the natural conditions that cause bulbs to bloom. The end results are flowers that bloom months before their usual cycle. Perhaps you have tried to force spring bulbs in the past, only to have their weak stems flop over, or to have the flowers drop just before opening. This is common, and is most often caused by lack of a cool period. The majority of spring-blooming bulbs need 10-12 weeks of cold outdoor temperatures after they are potted to develop roots that are strong enough to support stems and flowers. Growth of spring bulbs and corresponding temperature can be divided into 4 stages. Duplicate these 4 natural stages and they will flower earlier than normal. Stage 1 is dormancy, or near dormancy. This is when the bulbs are planted. Stage 2 is root growth. Light is not necessary for this stage, and temperatures should be in the 41° F – 45° F range. One of the best ways to maintain this temperature range is to bury the pots in the ground 6-8 inches deep. Other common areas used for rooting bulbs are cool cellars, old refrigerators, garages or outdoor sheds. Always keep the soil moist. If the temperature approaches freezing, roots cease to grow. When the temperature goes above 54° F – 55° F, top growth may begin prematurely. Stage 3 is when top growth begins. Light should be strong, but temperatures should be cool, in the 55° F – 65° F range. Stage 4 – After 2 to 3 weeks at Stage 3, move into a warmer temperature of 68° F – 72° F and watch the beautiful flowers pop into bloom. For forcing, use a good, well-drained potting soil. Don’t worry about fertilizer; the bulb contains all its own food. |