University of Illinois Extension

Winter Bulb Magic

Most people will describe winter using one word descriptors—cold-dark-icy-snowy, said Greg Stack, University of Illinois Extension horticulturist.

“Gardeners may also have similar responses but they may look at winter as a time to dream a little about next season’s garden and enjoy the colorful catalogs that find their way to the mailbox,” said Stack. “You can also temper those dark, dreary days with a little burst of color and fragrance by coaxing bulbs into bloom and taking the edge off of those long winter days.”

Forcing bulbs is not complicated and if you use the right ones, just about foolproof.

Amaryllis, paper white narcissus and hyacinth are bulbs that are available just about everywhere and easy to bloom. With a little planning, you can provide color and fragrance for a good portion of the winter.

“Let’s start with that dramatic, large amaryllis bulb,” said Stack. “These larger-than-life bulbs are easily forced into bloom. When shopping for amaryllis, look for large firm bulbs. The large ones often will produce two flower stalks while smaller ones only one. The pot you choose should be about one-inch larger than the diameter of the bulb.

“Position the bulb so that about one-third of the bulb is above the soil line and fill the pot with a prepared potting mix. Water well and place the bulb in a very well-lighted area with a temperature of about 65-70 degrees. The first thing you will see emerge is a flower stalk. When this happens, give the bulb plenty of light. If growing on a window sill, turn the pot daily so the flower stalk will grow straight and not bend toward the light. Flowering will occur in about six to eight weeks after potting.”

Amaryllis is also a bulb that can provide blooms for many seasons. After flowering cut the spent flower stalk off and allow foliage to develop. Water as needed and fertilize every two to four weeks. When all danger of frost is past in your area locate the bulb, pot and all in a semi-shaded area of your garden and water and fertilize all season. The leaves that are growing are manufacturing food reserves for next seasons flower. Just before frost take the bulb indoors and let the soil dry out and the leaves turn yellow. Store the bulb in a cool dark location for two four months. After this rest period, the bulb can be brought out to a growing area and once again produce a dramatic display of flowers.

“Paper white narcissus is perhaps the easiest bulbs to force into flower,” Stack said. “All you need are bulbs, a shallow tray, gravel and water.”

Select firm bulbs for growing. Fill a shallow tray or pot saucer with decorative gravel, pea gravel or marbles. Nestle bulbs into the gravel to hold them upright. Place the bulbs shoulder to shoulder for a really nice display. Fill the tray with water to just below the base of the bulbs. Place the tray in a very well lighted spot. If you can keep a temperature of 50-60 degrees, this will help keep the shoots short and not fall over. You will be rewarded with very fragrant blooms in about four to six weeks. If you want to have a continuous show of flowers, plant some bulbs every two to three weeks.

“You’ll get a succession of bloom all winter,” he said.

The last bulb to add some color to your winter indoors is the hyacinth.

“The trick for hyacinth to bloom successfully indoors is to chill the bulbs,” he said. “Hyacinth bulbs are often forced using a hyacinth glass. This looks like an hourglass with the bulb going in the top and water is in the bottom. Place the bulb in the top portion and fill the bottom so the water is just below the base of the bulb. Don’t have the bulb sit in water.

“Now find a cold, dark spot. A refrigerator works well or an unheated space that stays between 35-40 degrees is also good. The bulbs will stay here for about 13-14 weeks of chilling while roots form. If the chilling period is not long enough the stems on the blooms will be very short and disappointing.”

Check the vase and add water as needed. After chilling, the shoots will be about two inches high and a yellow green and the lower part of the container should be full of roots. At this time move them to an area that is about 50 degrees. Leave them here for about three to four days while the shoots green up and then move them to an area that is about 60 degrees and allow them to flower. Hyacinth will flower in about three weeks after you take them from the cold storage area. This bulb involves a bit more work but once you smell the fragrance of hyacinth in the house you’ll think it worth the effort.

“Another way to provide the chilling time needed and not place the bulbs in the hyacinth glasses right away is to place the hyacinth bulbs in a paper bag and put the bag in the refrigerator for 13-14 weeks,” Stack said. “Locate the bag away from any ripening fruit. After that the bulbs can be placed in the hyacinth glasses for final forcing.”

Hyacinth and paper white narcissus don’t offer much garden value after they are forced so they are often best discarded.

“Here are a few ways to get over the cold, dark, snowy, icy days of winter,” he said. “Work a little bulb magic and enjoy your time indoors as you watch the snow fly.”