Spring bulbs, such as tulips and daffodils, are usually planted about six weeks before the ground freezes, in late October or November. If the bulbs are planted too early while the ground is still warm (above 55 to 60 degrees Fahrenheit), the bulbs might even start to grow prematurely. The soil has probably cooled enough for planting when the temperature has been 55 degrees or below for about two weeks. Sometimes, however, gardeners may wait too long to plant their spring bulbs and find that the fall has passed and winter has begun. Nevertheless, spring bulbs can still be planted in the winter.
Choose a site for your spring bulbs. Most spring-flowering plants prefer a place in full sun or partial shade, so choose a site accordingly. You can also plant many spring bulbs underneath deciduous trees. These trees will usually not begin to produce leaves---and, therefore, shade---until after your spring flowers have bloomed, which means the spring flowers will get the necessary sun.
Dig a hole the appropriate depth. A good rule of thumb is to plant your bulbs a depth three times the size of the bulb's diameter. You can also consult the chart on the back of any packaged bulbs you have bought for the correct planting depth.
Work in organic material if necessary. If your soil seems heavy, (does not crumble easily in your hand) add some organic matter, such as compost or dead leaves, to the planting hole. This will add nutrients to the soil and help improve the drainage.
Cover the planting area with 3 to 4 inches of mulch to help protect the bulbs during the remainder of the winter.
Water for about 10 to 20 minutes. This will provide them with about an inch of water, which will encourage the bulbs to start forming deep roots.