Forcing Bulbs for Winter Color — Indoors
Not a year goes by, not a holiday season approaches, that we wish that we had started some flower bulbs in containers for indoor growing so that we might give the gift of color to our nearby friends and relatives. And not a year goes by that we realize we didn’t plan far enough ahead. Think of delivering bright red amaryllis to the hosts of the neighborhood Christmas party or bringing a cluster of paperwhite blossoms on sharp green leaves to Aunt Susan when she hosts a holiday dinner. Having plants ready to go for the last weeks of December means preparing in September and even August to make sure bulbs will be willing to grow just when you want them to.
Forcing bulbs for winter color is a matter of persuasion. You must fool them into thinking (thinking is a relative term here) that they’ve gone through winter and are approaching spring. We do this buy digging or buying bulbs late in the summer and then keeping them in the refrigerator for two or three months. Then we pot them up, whether in organic compost or potting soil for bulbs including amaryllis, or in pebble pots or glass containers for paperwhites.
Many nursery and mail order sites now do the work for you, keeping bulbs in cool, winter-like conditions so that they’ll be ready to grow when brought to warmer, moister conditions. Some even have the bulbs already planted and ready. You can do this to, though it’s often difficult to find a place to store potted bulbs at an ideal 40˚F in September, October, and even November.
The longer bulbs are kept in these cool conditions (up to three months or so, longer for tulips), the stronger the growth and flowering. Bulbs that aren’t given proper chill conditions or those removed from cold too soon, don’t grow as well and may not flower. As the potted bulbs chill, they’ll send out roots. That’s just what you want. The cool conditions will keep them from going to far. Keep the growing medium moist but not too damp during the rooting and shooting period.
Hyacinths, tulips, and daffodils are all good choices for indoor forcing (hyacinths are the easiest). Smaller bulbs, like snowdrops and crocus, are also good for indoor forcing. The University of Missouri Extension service has a good guide of which varieties of tulips, hyacinths and daffodils are best for early and late season forcing (as well as detailed growing instructions).
When planting bulbs for forcing, crowd them in. The tighter they’re packed into your container, the more growth and color you’ll have. Paper whites are easily grown in pebbles or coconut coir. If using a glass container — it’s great to be able to watch the roots develop– make sure it has drainage. When planting bulbs in soil, have the shoot tips poking through the surface. Smaller bulbs can be completely covered, but not deeply. Refer to the University of Missouri Extension site to see how deeply to plant various types of bulbs.
When you see white roots spreading through glass containers or shoots of a couple inches breaking the soil, it’s time to bring your bulbs into the light of day. Place them in a cool, shaded spot that mimics early spring conditions to start before placing them near a sunny window. Amaryllis like warm temperatures when they’re first growing — up to 75 degrees — then as they begin to blossom should be moved to a cooler place between 65 and 70 degrees.
Everyone has different methods — and different favorites — when it comes to growing bulbs indoors. A lot of what you do depends on the conditions available in your home, what you have planted outside, and the fall conditions you experience. Here’s more information worth reading before getting started. The important thing to remember is that forcing bulbs indoors is actually easy. It’s a great project for the kids, one with visible (though not too quick) results. And think what joy it will bring when you place a festive red-and-green amaryllis display on your holiday table. First entry on my list of New Year’s resolutions? Next year, I promise to plan ahead.