On your windowsill you can have bowls of fragrant paperwhites, tiny daffodils , freesia perfuming the entire house, and pots of tulips - weeks before the arrival of spring.
Forcing these bulbs is simply a matter of chilling the plants or bulbs just long enough to allow them the necessary period of winter dormancy, which ranges from 10 to 16 weeks.
One of the easiest bulbs to force is the paperwhite narcissus, which takes very little encouragement to bloom. Just set the bulbs in a bowl of pebbles and fill with water till it reaches the base of the bulbs. Place on a sunny windowsill in a cool room and, very important, be sure to maintain the water level.
When you first notice the roots or green shoots coming from the bulbs, you may move them to a warmer location. Remember, the bulbs are very tender and should never be put outdoors. Too, do not expect them to bloom a second season.
Hardier bulbs require a longer period of cold storage before forcing, among them: tulips, crocus, and freesia. After they have bloomed, however, they may be planted outdoors and you should have flowers from them the following year.
If you follow the simple rules - first, cold storage, then planting in pebbles, adding water, keeping the bulbs in a cool room until they start to bloom, and finally, moving them wherever you want them - you should have no trouble.