Last fall, while most gardeners were putting in tulip bulbs, the spring-flowering shrubs were quietly going about the annual business of producing the buds from which long-awaited flowers will begin sprouting about a month from now. While we shivered through the winter thinking that the snow-covered branches were asleep, they were, in fact, readying themselves for the spring show. Eight weeks or so of chilling time is a necessary tonic to spring flowering shrubs, as essential to the flowering process as sunlight and sufficient water. While we were complaining, the shrubs were preparing. It would be a stretch to say that they are smarter than we, but they certainly have better instincts.
Starting now, we can reap the benefit of that instinctive behavior by collecting flowering branches, carting them inside and forcing them into bloom. This practice, which has been going on for ages, has the benefit of bringing spring into the house at a time when it is much needed. It is also multi-tasking at its best, because intelligent branch cutting can also serve as a mini-pruning process, opening up congested areas of the shrubs.
The list of shrubs suitable for forcing is a long one: beauty bush, spirea, deutzia, clove currant, forsythia, lilac, pussy willow, spicebush, witch hazel and even wisteria, to name a few. I would recommend trying the procedure with any spring flowering shrub. You have nothing to lose. Some flowering trees also make good forcing subjects. These include buckeye, flowering dogwood, flowering cherry, magnolia and redbud. Fruit trees are another possibility, but remember that diminishing the number of flowers on the trees also diminishes fruit production later on.
The forcing process takes anywhere from two to five weeks, depending on the plant species. It begins with collecting budded branches. Pick a day when the weather has been above freezing for several days. Use sharp clippers and cut off branches that are about eighteen inches long. Try to select branches that you might prune anyway because they cross other branches or give the shrub a lopsided appearance. Bring them into the house and recut the stems at an angle. Choose a tall vase, bucket or other container and fill with about three inches of warm water. Place the branches in the water and let them sit for 30 minutes. If you have some commercial flower food, add the powder or gel to the water in the container. If not, make your own flower food with two tablespoons each of sugar and white vinegar, combined with half a teaspoon of chlorine bleach in one quart of water. After the thirty minutes has elapsed, fill the rest of the container with either plain water, if you have already added commercial flower food, or the homemade flower food mixture. Place the container in a shaded, relatively cool location, where the temperature will not go above sixty-five degrees.
Check the branches every few days and top off the water level as needed. When the flowers on the branches begin to show color, arrange them in a decorative container and display them. They do best when they are not in direct sunlight. To keep the show going for as long as possible, move the branches to a cool location at night.
In my observation, every household has at least one denizen, like my husband, who prefers to keep the temperature borderline-chilly at all times. If your household matches that description, there is no need to move the vase full of branches, as it is already cool enough. Instead you may want to move yourself to a warmer place from time to time.
This weekend, I intend to brave whatever elements are at work in the environment and collect a few branches from the flowering quince, clove currant and spirea in the front garden and the lilac in the upper back. I’ll check the abelia for signs of budding as well. The greatest hazard will be the thorny quince branches, which I always forget about until I am impaled for the first time each spring.
The excellent people at Purdue University’s Cooperative Extension Service have put out a nice two-page procedural on flowering branch forcing. It includes a handy chart listing shrub species, forcing times and details about the appearance of flowers and buds. It is available at http://www.hort.purdue.edu/ext/ho-23.pdf.
We gardeners are always trying to force things—from hyacinths to quince branches—as a way of getting early relief from the end-of-winter doldrums. This year we need it more than ever.