Spring bulbs provide indoor winter color

Last Updated: 
February 3, 2009

"'Forcing' spring bulbs is easy to do," said Linda McMahan, a horticulturist with the Oregon State University Extension Service in Yamhill County, "but it requires a bit of planning now to get beautiful blooms in February. Bulbs that are growing or budded also make great holiday or late winter gifts."

Early blooming tulips, daffodils, hyacinths, snowdrops and crocus are good choices for potted blooms in winter. Many of the dwarf or shorter tulips and daffodils are particularly attractive, and their shorter size makes them more versatile for forcing, according to McMahan.

These so-called "hardy" bulbs require a chilling period to bloom. If the bulbs were planted outside in the garden, this chilling process would occur naturally. Some bulbs are sold "pre-chilled;" check the information that comes with the bulbs.

If the bulbs are not pre-chilled, it will be necessary to chill them first in the refrigerator for 12 to 16 weeks to "force" the bloom indoors. Check instructions that come with the bulbs you select for precise temperatures and lengths of time.

Choose large bulbs that are firm and unblemished. "If the bulb is the type with a papery covering, choose only bulbs with that covering in tact and no mold or decay evident," McMahan said.

Place bulbs in a paper bag in the refrigerator until you are ready to pot them. Or pot them first and place the pots in a cool location outside or in an unheated garage or basement. McMahan advises making the date of removal on your calendar so you won't forget them.

"Choose the right container for potting," McMahan said. "Those that are six inches deep and six to eight inches across with bottom drain holes are best for forcing larger bulbs." For small bulbs such as crocus, a smaller and shallower container will be more in scale with the flowers. Special shallow forcing pots are available sometimes at garden centers.

Most commercial potting mixes work as a suitable growing medium, and McMahan suggests placing a layer of gravel or potshards in the bottom of the pot to improve drainage. Plant daffodil, tulip and hyacinth bulbs so that the pointed tops are just above the soil level. Plant small bulbs, such as crocus and snowdrops, so that the bulbs are barely, but completely covered. Keep slightly damp during chilling, and after chilling, water well to stimulate growth. Label pots with the bulb type and planting date.

You may be able to purchase potted, pre-chilled bulbs at local nurseries later in the fall. They are ready to take home; all they need is a sunny window to grow and bloom.

After the bulbs have been chilled and potted, bring your pots indoors and watch spring unfold. Place pots where they will receive at least eight hours of light, with daytime temperatures around 60 degrees and nighttime temperatures around 55 degrees. Keep the pots evenly moist, but not soaked.

You should have a bowl of bright and maybe even fragrant flowering bulbs two to four weeks after the pots are moved inside.

After the blooms have faded and the tops have died down, transplant the bulbs to your garden where they will bloom for you again next year.

Author: Judy Scott
Source: Linda McMahan