Forcing Bulbs

For northern gardeners, winter brings five long months of gardening withdrawal. To these hibernating souls, it must seem like gardeners in Cochise County barely catch their collective breath between when winter arrives and the first spring flowers emerge. And yet, as many of us gardeners know all too well, southwesterners suffer from the same impatience with the lingering winter as our more northerly compatriots. Most of us manage to hang on until mid-March only to succumb to the lure of early spring bedding plants which become pansy-popsicles at the next frost.

Fortunately for both northern and southern gardeners, not to mention those poor unsuspecting bedding plants, there is a healthier alternative: growing flowering spring bulbs indoors. Growing bulbs indoors, also known as forcing, is even easier then growing bulbs outdoors since you alone control the climate (and bulb-eating critters) in your home or greenhouse. All you need is a little information, a handful of leftover bulbs, an assortment of planting mediums and containers, a little water, and a lot of sunshine.

Some of the more popular and successful bulbs for forcing are amaryllis, paperwhites, hyacinths, and crocuses, although any spring bulb can be made to flower indoors if given the right conditions. Hyacinths, tulips, and daffodils need a period of cooling in order to bloom, something which occurs naturally outdoors during the winter months. Simulate this cooling by storing the bulbs in an unheated garage, cold frame, or refrigerator for twelve weeks prior to planting. The bulbs should be moved from cooling after twelve weeks (some bulbs may even have started shoots!). Some spring bulbs, such as paperwhites, do not need cooling, so it is important to read the label on the bulb package to be certain.

Once the bulbs are ready for planting, you need to select the proper planting medium. Most bulbs can be grown in a quality commercial potting soil or a mixture of one part peat, one part perlite, and one part garden soil, and can be crowded together in a pot much closer than is recommended for planting outdoors. Plant the bulbs point up and deep enough so that only their tips show above the soil. Water them thoroughly and place them in a south or west window where they will get plenty of light. Ideal growing temperatures are between 55 and 65 degrees Fahrenheit. Keep the soil moist but not soggy and make sure to provide for drainage. Growth should be rapid at this point with blooms appearing in three to five weeks (depending on Ae type of bulb).

Hyacinths and paperwhites can also be grown in a low shallow dish filled with pebbles to support the bulbs. Keep the water level in the dish just below the bulb base; any higher and may rot the bulb, any lower and you will dry out the tender new roots.

A favorite tropical bulb for growing indoors is the amaryllis, largely because of its big, bold flower. The amaryllis is one of the few bulbs grown indoors that will bloom in successive years. Many bulbs that are forced resist blooming a second year. To prolong the productive life of your indoor bulbs, and outdoor bulbs for that matter, keep the leaves healthy for as long as possible since they will be providing the energy for the next year's bloom.

Author: 
Jackie Dillon-Fast
Issue: 
December, 1992
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