Hartley Magazine

All the latest news, hints, tips and advice from our experts

Forcing Branches and Bulbs in the Greenhouse

As we step into the new year, celebrate the transition with an early dose of spring by “forcing” some winter branches or dormant bulbs. (Not as violent as it sounds, forcing simply means encouraging plants to believe it is a different time of year—in this case, not winter—so that they bloom.) A sunny January day is the perfect time to head out, loppers in hand to find branches for such projects, and potting up bulbs indoors isn’t a bad way to spend some hours of stormy mid-winter weather.

Quince, plum, forsythia, witchhazel, willow, apple or pear all make fine forcing subjects. Carefully select branches that have numerous flower buds. Don’t let them dry out—plunge the branches into warm water within twenty minutes of cutting. Change the water every few days, and store out of direct sunlight. Maintain cool (50-60◦F), humid conditions; a large plastic bag or tarp can help. The closer to their normal bloom time, the more quickly the buds will open—generally 1-4 weeks. Arrange the branches as their buds begin to swell; once they’re open, move to a brighter location. Cooler temperatures will help flowers last.

Although most bulbs require months of cold before bloom, a few are quicker. Amaryllis and paperwhites are both ideal for forcing.

Plant amaryllis in a container 1-2” wider than the bulb’s diameter. Leave one-third to one-half of the bulb’s top above the soil. Place in a sunny, warm (55◦) location. Keep moist, especially once flowering begins.

To force paperwhites, fill a shallow container with 2-3” of pebbles, sand, or soil. Set bulbs on top (pointy side up) and add enough medium to hold them in place. Water well in cool (55-60◦), low light until roots develop. Move to the sunlight to bloom.

After flowering, most bulbs are too exhausted to bloom another season. If you can’t bear to throw them on the compost pile, cut off the flowers, and keep the leafy bulbs watered until they can go outside. After a season of recovery planted in the ground, hardy bulbs can resume a normal life, blooming in sync with their unforced brethren. But dig up tender bulbs– such as Amaryllis– before hard frosts and repot them indoors. With fresh soil and fertilizer, Amaryllis usually bloom every winter– you’ll be amazed by the increased size of your bulb after it summers in the garden!

These “forced” glimpses of spring might just help you endure a few more dark and cold days of winter.