[Skip to Content]
University of Illinois Extension

Start Spring Bulbs for Winter Forcing

October 1, 2012

While planting your bulbs this year, consider forcing a few for indoors. The long nights and cloudy bleak days make winter really dreary for most avid gardeners. One way to break up winter is to force flower bulbs to bloom indoors in mid-winter. Additionally, bulbs forced in early November will produce Christmas blooms. Popular bulbs to force at Christmas time include paper white narcissus and amaryllis.

Many of the bulbs available for planting outdoors can be potted and forced indoors. Many tulip varieties, crocuses, daffodils, squills, and hyacinths are easily forced. Varieties most easily forced are usually marked as such in store displays and catalogs.

To be forced into early bloom, bulbs must have a cold treatment, which allows bulbs to develop roots and buds to break dormancy. The bulbs then need a warm treatment indoors to force them into bloom.

To pot the bulbs, loosely fill a container about halfway with a well-drained soil. Do not firm the soil since this could cause poor drainage, which would rot the bulbs. Set the bulbs so that they are just touching each other, and the pointed tips are just showing above the rim of the pot. Firm the bulbs into the soil; then add soil between the bulbs to within about one-half inch of the pot rim. Water thoroughly.

Store the potted bulbs where they will receive cool (not freezing) weather for about 13 weeks. An unused refrigerator or even the household refrigerator if you can get away with it, an unheated garage, a cold frame or a protected place outside is satisfactory. If outdoors, store potted bulbs under mulch such as leaves, straw, or sand. The mulch needs to be 8 to 12 inches deep to prevent the soil from freezing and the pots from cracking. If possible, place the pots in a shallow ditch or hole and cover with the mulch. You may need to use screen wire to keep out mice and other animals.

In February, bring the pots in, keep at room temperature of about 50 degrees for one week, and then increase the temperature to 60 degrees. Flowers will develop in about 4 weeks. If several pots are planted, bring in one pot at a time at two-week intervals to provide a continuous flower supply.

When the flowers are done, you can plant them outside. Just knock them out of the pot and plant them into the outside garden. Leave the foliage on. It may take a season or two for them to reflower due to the forcing process.

Use forced bulbs to welcome spring into your home early next year. For as a Chinese proverb states, "Spring is sooner recognized by plants than by men."

Source: Rhonda J. Ferree, Extension Educator, Horticulture, ferreer@illinois.edu

« Back to News Releases