By Marilyn Homewood, Master Gardener
As winter seems to drag on, why not have spring start inside by forcing blooms from some of your favorite woody plants?
Many ornamental trees and shrubs set their flower buds during the previous growing season. These buds must experience a period of dormancy (usually 6 weeks of cold weather) before they will open. As a rule, the buds will usually come out of dormancy within two to three weeks of exposure to warmth and moisture.
Coincidentally, late winter can be a good time to “clean up” deciduous trees and shrubs. Prune plants lightly by removing crossed branches and old or diseased wood keeping in mind to leave some buds to bloom in the garden. From the cuttings, select out branches of less than ½ inch diameter for forcing and trim them to a manageable length.
Pruning is best done on a mild winter day when the temperatures are above freezing. The branches and buds are softer and more pliable and transition from cold outdoor temperatures to the indoor temperatures more readily. Try to select branches that seem to have a lot of plump flower buds. In general, flower buds are round and fat, whereas leaf buds are smaller and pointed.
Once inside, recut the branches to open up the vascular system of the branch and encourage water uptake. Woody branches do not take up water as easily as green flower stems so they should be cut at the end of the stem for roughly an inch or so with sharp pruners.
Larger diameter branches can be cut twice at right angles. Place the branches into a bucket of warm water to rehydrate. Keep the bucket in a cool, dark place overnight to allow branches to rest (this also helps them to transition from the outdoors).
After resting, prepare a vase of fresh water for your branches and recut the stems again before placing in vase. Adding a few drops of bleach to the water will help keep bacteria from multiplying in the water and plugging up the vascular system. Place your branches in a bright, cool place away from direct sunlight.
Changing the water every few days is recommended. The time taken to bloom depends on when the branches were harvested. Branches harvested in mid-winter can take 2 to 3 weeks for flowers to open. Branches harvested in late winter will bloom in 7 to 10 days.
After blooming, keep the branches away from direct sunlight and away from any direct heat source, which will dry out the buds and branches and reduce overall bloom color and quality. Ideally, try to duplicate the cool, moist environment of the spring. Once in flower, branches should last in the vase for 10 days. Changing the water frequently and adding flower food will also help to extend their life.
Some of the species that force well are forsythia, fothergilla, witch hazel, ornamental pear, cherry, birch (for catkins), eastern redbud, lilac, magnolia, serviceberry and willow (for catkins). Or try experimenting. I have some Red Osier Dogwood in a vase at the moment. The red stems are attractive and although I expect to get foliage perhaps a few tiny flowers may appear.