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Forcing plants to bloom

The word "forcing" has a negative connotation. Most humans don't like to be forced to do anything. But in the horticultural world "forcing" is a lovely thing, a pleasant trick we play with plants. In this context, "to force" means "to cause a plant to produce leaves or flowers outside of the normal time period for that species."

At the upcoming Plantasia show (March 23-26 at the International Agri-Center, Hamburg Fairgrounds), you will see thousands of plants forced to leaf out and flower unnaturally, or there wouldn't be a flower show at all! It takes skill and luck for growers and nurserymen to time plant care to produce flowers for these precise show dates. However, with less pressure you too can do some "forcing" for an early glimpse of spring.

>Forcing branches

Almost any tree or shrub branch can be forced to produce leaves or flowers to enjoy indoors, as long as the plant has had at least six weeks of cold temperatures. (In spite of fluctuating temps, most should be ready to break dormancy from now on.) Timing varies by plant. Good results come from pussy willows, Amelanchier (Serviceberry), dogwoods, Forsythia, Spirea, horse chestnut, apples, cherries, maples -- or whatever leafy old friend you miss. Here are the steps:

*Select branches with many buds, and make a clean cut, flush with the plant stem. (Don't leave ragged edges, or damage the mother plant.)

*Shred or mash the cut ends to increase water uptake. Lay the branches in a bathtub filled with warm water overnight.

*Store branches with cut ends immersed in water in a 60- to 70-degree location. For the first week or two, it is OK if the location is dark (such as the cellar.)

*When you see buds becoming plump, display the branches in your home. (For longest display, move to a cool place at night.) You may re-cut and re-mash the branch ends and refresh the water every few days.

>Forcing bulbs

If you forgot to plant bulbs last fall, or find some left over in a garden center, you can force them in pots for indoor bloom. Any bulbs will do. First, feel them for firmness, and discard if they are soft or shriveled. Get the best potting mix you can, clay pots that are wider than they are tall (preferred over plastic), and pre-soak the clay. You are prepared for forcing:

*Plant them: Fill the pot with planting mix to about 1 1/2 inches from the top of the pot. Set the bulbs halfway into the soil, point sticking out, touching shoulder to shoulder. Soak once.

*Chill them: Most bulbs need eight to 10 weeks of cold treatment to grow roots and stems. Use an unheated garage, refrigerator or basement, under 40 degrees, or place outside against the house and mulch them. Water lightly when un-frozen. During a mild spell you could also sink the pots into the ground, cover with soil and leaves, and mark well.

*Once you see well-developed shoots, bring them into the light. Water, and keep them cool for longer performance.

Sally Cunningham is a garden writer and former Cornell Extension educator.

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