(Editor's Note: This article was originally published on January 18, 2008. Your comments are welcome, but please be aware that authors of previously published articles may not be able to promptly respond to new questions or comments.)
When experts talk about pruning spring-flowering trees and shrubs, they advise waiting until after they have bloomed, in order not to prune away the blossoms that would otherwise bloom in the spring. Pruning is not usually the same as cutting the branches for forcing. Most people are familiar with forcing pussy willow or forsythia blossoms for an early taste of spring bloom in late winter. But the same techniques can also be used to force the buds of dormant fruit trees into bloom. The blossoms of fruit trees are some of the most attractive flowers of spring, and most varieties are suitable for forcing: apples, pears, plums, peaches can all make an attractive display in a tall vase long before the trees outside are beginning to open their buds. And of course you were going to prune them anyway, weren't you?
Pruning fruit trees is done primarily to optimize fruit production, and there are different techniques for different varieties of trees. But most fruit trees do require annual pruning during the dormant season to thin out excess growth from the year before. So instead of throwing all these branches into the chipper, why not take the best of them inside to force into bloom?
Most spring-blooming fruit trees suitable for forcing have what is called a chill requirement. This varies from one variety to the next, but is most typically about 8 weeks. That is, the tree needs to spend that amount of time dormant in the winter when the temperature is below 40o F. Without sufficient chilling, the tree will not bloom or produce fruit - this is why most apples, for example, can not successfully be grown in the deep South. For the same reason, if you want to cut branches for forcing, you should wait until January or February, depending on your zone, so that the buds will be ready to open. If you can, prune on a day when the temperature is not below freezing.
Once you have pruned your tree, you need to select the branches that will produce the best display of blooms when forced. Most types of trees - many apples are an exception - bear most of their fruit on year-old wood, the branches that sprouted the year before. Look for well-formed, younger branches about three feet long that have abundant flower buds. Flower buds and leaf buds have a different appearance. Flower buds are rounder and fatter; leaf buds are usually thinner and pointed at the tip. Trees and shrubs suitable for forcing are those that flower before their leaves emerge, like fruit trees.
Forcing the branches of any flowering shrub into bloom is primarily a matter of convincing them that warm spring weather has arrived and it is time to break out of dormancy. But this has to be a gradual process. After bringing the branches inside, make a fresh cut at the bottom of the stems so they can take up water more easily, then place them in cool water to soak. The ideal location is no warmer than 60o and away from heaters that will dry the air and also away from direct sunlight. The basement may be a good place. The branches must not be allowed to dry out. The cooler the temperature, the longer it will take the buds to open, but the longer the blooms will last. If possible, add florist's preservative to the water and be sure to change it if it discolors or starts to smell bad.
It will take two or three weeks for the buds to begin to open, depending on the variety. When you see the first signs that they are ready to pop, make another fresh cut at the bottom of the branches, then arrange them in a vase with fresh water and place it on display. As the buds begin to open, it will be spring inside your house, even if a late snowstorm is falling outside.
Photo credits: Thanks to Dea for the flowering cherry blossoms