Forcing Bulbs for Midwinter Color
November is a good time to plant spring-flowering bulbs in containers to be “forced” into early indoor bloom. Daffodils, tulips, hyacinths, and dwarf iris are among the easiest types of bulbs to force. If you don’t have fresh, unplanted bulbs on hand, specialty catalogs and retailers often recommend and stock the best varieties for forcing.
To start an indoor bulb garden, use shallow pots four to 12 inches wide with drainage holes. Partially fill them with a commercial soilless mix or a homemade mixture of one part garden soil, one part peat moss, and one part perlite. Then place a single layer of fresh bulbs with their noses pointing up and the sides of the bulbs just touching each other. Cover the bulbs with enough mix to almost cover the tips and water thoroughly.
Most spring-flowering bulbs need a period of cold between eight to 16 weeks. Generally, the bigger the bulb the more time it needs. Mimic winter’s chill by placing containers somewhere dark where temperatures will remain between 35 and 45 degrees. Good places to consider are an unheated garage or shed, a window well filled with 12 inches of mulch to cover the pot, or in a sealed plastic bag in a refrigerator free of ripening fruit — places where temperatures will remain between 35 and 45 degrees. Check the bulbs monthly and water as needed.
During the chilling period, bulbs produce roots. Once roots have filled the pots, shoots will emerge signaling it’s time to remove that pot’s plastic bag and move it to a cool room with bright but indirect light. As buds develop, move pots into a warmer room, still with indirect light, and keep soil moist until flowers bloom, usually in two to four weeks. A few pots of spring-flowering bulbs planted now will provide color at a time when winter’s grip often leaves gardeners longing for natural beauty