Forcing Branches

            Here we are in February, longing for the sunny days and bright flowers of spring. While we cannot change the weather, we can encourage spring blossoms for our homes.

            Branches of your favorite flowering trees, shrubs, or fruit trees can be cut and forced into bloom indoors.  Flowering shrubs are fairly easy to force, while trees are little harder. The process is not difficult, but there are a few important details.

Branches from shrubs will bloom in a week or two; those from trees can take up to four to six weeks. The closer it is to the shrub's normal flowering time outdoors, the more quickly the buds will open indoors. Forsythia, quince, and pussy willow branches brought in towards the end of February should open up quickly. For apple, dogwood, peach, plum, and lilac, you should wait until about the middle of March before cutting them and bringing them indoors to force for blooms.

            After we have had 6 weeks of very cold weather, you can begin forcing branches. When choosing your branches to cut for indoor use, look for the fat flower buds (leaf buds will be smaller), and always cut the shrub with an eye towards improving the shape of the plant. Choose branches from crowded areas when possible, since you will be removing some of the plant’s natural spring display. Follow good pruning practices when cutting the branches. Cut about ¼-inch above a side bud or branch so that no stub is left behind. Cut the branches in lengths of 6 to 18 inches as longer branches are easier to use in flower arrangements. Using sharp pruning shears, make your cuts diagonal, and flush with a major branch. You should cut your branches in the middle of a mild day when the daytime temperature is above freezing.

            In the dormant season, the flow of water through deciduous trees and shrubs slows to nearly half, so to promote forcing, the branches need to absorb all the water they can, as if they were about to break dormancy and soak up spring rains. Once you have the branches indoors, make a one- to two-inch split in the stem bottom. If it’s a woody stem, gently mash the ends with a hammer.  Place them in a tub of water so they are completely submerged for three to four hours, then move them to a deep container of tepid water. Soaking them helps to clean off the bark and also softens up the buds scales. Many people do it to hasten the bloom, but it is not             essential. The stems will force just as well if they are just placed in a deep container of warm water.

            Place the branches in a cool, dimly lit area until the buds start to show some color; temperatures of around 60°F are ideal. Be sure to change the water a couple of times a week.   You can also add a preservative solution to the water. If you have a leftover envelope from the florist, it will work fine; to make your own use 2 tablespoons of white vinegar, 2 tablespoons of sugar, and ½ teaspoon of chlorine bleach. This is enough preservative for one quart of water.

            Misting the branches daily will hasten the blooming process. When the buds begin to show color, transfer them to a vase and move them into a well-lit room. Direct sun should be avoided as it will dry out the branch and shorten the life of the blooms.

            While the flowering branches make a spectacular display by themselves, they can also be combined with evergreens and purchased flowers to make interesting arrangements and bouquets. Acuba and boxwood blend well with many branches. Privet, which also works nicely, can be forced in about two weeks.

            While you are forcing your branches, some may root. If you want to use them as new plants, remove them from the water when the roots are about ½ inch long. The branches should be trimmed to 6-8 inches long and potted individually. Keep them moist until permanent roots are formed and plant them outdoors after the danger of frost has passed. It may take several years for your new plants to bloom, depending on the variety.

            The following shrubs should bloom within two weeks of cutting: forsythia, bridal wreath, flowering quince, spirea, pussy willow, spice bush, shadblow, and witch hazel. Fast blooming trees include Cornelian dogwood, red maple, birch, and hickory; if you try redbud, it should be cut in March. Also consider forcing honeysuckle to add variety to your indoor displays.  Apple, pear, plum, and peach will also be a treat for the eyes.

            For the more patient among us, try your hand at flowering almond, lilac, mock orange, rhododendron, wisteria, and crabapple, all of which should bloom in three to four weeks.

            If you are really adventurous, push on to red twig dogwood, buckeye, flowering dogwood, and magnolia; these will take about 5 weeks to greet you with their blossoms.

Just about everything that is dormant can be forced. There are many other options not mentioned here. Be adventurous; try branches with different blooming times to lengthen the time you have blossoms in your home or cut the same ones at different intervals. Enjoy an early spring!

Sources:

            Purdue University Cooperative Extension, “Forcing Branches for Winter Color,” Rose Lanier and Michael Dana

            Gardening by the Yard, Episode 408, GHTV

Written by members of the Heart of Virginia Master Gardeners

posted 3/1/07