Tulips, daffodils, crocuses, and other spring-flowering bulbs are a welcome sight in the garden in the spring. Many spring-flowering bulbs also can be forced indoors during winter.
When buying bulbs, select large, firm bulbs. Avoid soft or blemished bulbs. Small bulbs may not bloom well.
Forcing Spring-Flowering Bulbs Indoors
Spring-flowering bulbs that can be forced indoors include tulips, daffodils, hyacinths, and crocuses. While many bulb varieties can be forced, best results are obtained by selecting varieties recommended for forcing. To enjoy spring-flowering bulbs in winter, gardeners must begin the forcing process in late summer or early fall. Gardeners need good quality bulbs, well-drained potting soil, and containers with drainage holes in the bottom.
Begin by partially filling the container (pot) with potting soil. Set the bulbs so that the tops of the bulbs are even with or slightly below the rim of the container. Place additional potting soil around the bulbs. However, don't cover the bulbs completely. Allow the tops (noses of the bulbs) to stick above the potting soil. After potting, water each container thoroughly.
In order to bloom, spring-flowering bulbs must be exposed to cold temperatures (35 to 45 F) for 12 to 16 weeks. Possible storage sites include the refrigerator, unheated garage, root cellar, or cold frame.
Once the cold requirement has been met, begin to remove the potted bulbs from cold storage. For a succession of bloom, remove pots from storage at 10 to 14 day intervals. Place the bulbs in a cool (50 to 60 F), semi-dark location. After several days, move the plants to a slightly warmer area that receives bright light. Keep the potting soil evenly moist during the forcing period. Flowering should occur in 3 to 4 weeks.
Planting Spring-Flowering Bulbs Outdoors
October is the ideal time to plant spring-flowering bulbs in the garden. They can be planted as late as December if the weather permits.
Most bulbs should be planted in partial to full sun. Bulbs also need a well-drained soil. Poorly-drained soils can be improved by incorporating organic matter, such as compost or peat.
Plant spring-flowering bulbs in clusters or groups to achieve the greatest visual impact in the garden. When planting daffodils or tulips, plant five or more bulbs of the same variety in an area. Smaller growing plants, such as grape hyacinths and crocuses, should be planted in drifts of 25 or more bulbs. Plant bulbs at a depth equal to two or three times their maximum bulb diameter. Accordingly, tulips and daffodils should be planted 6 to 8 inches deep, crocuses and grape hyacinths only 3 to 4 inches deep.
Forcing spring-flowering bulbs indoors is an excellent way to brighten the gray, gloomy days of winter. Planted outdoors, the bright, cheery flowers of spring-flowering bulbs herald the beginning of spring.
This article originally appeared in the August 23, 1996 issue, p. 146.