While enjoying the branching pattern of trees and shrubs, I am reminded why we prune them.
Pruning corrects undesirable growth, controls size and shape, prevents crossing branches, encourages flower production, and removes damaged, dead, and low hanging branches. The next question is when to prune.
The worst time to prune is at bud break in the spring. The tree or shrub is using all of the stored energy from the last season to develop leaves. At this time, injuries are much worse. Another undesirable time to prune is during leaf drop in the fall. The plant needs energy to close the surface area where the leaf was attached to the tree or shrub. Furthermore, do not prune a tree or shrub when the wood is frozen. This will damage the plant’s water-conducting tubes called xylem.
One way to determine when to prune is based on the flowering period of the ornamental shrub or tree. If showy fruits are a feature of the plant, remember that the fruits develop from the flowers. Removing the flowers also removes the fruit.
For instance, shrubs that flower before the end of May should be pruned during or immediately after flowering. The flowers are formed on wood from the previous summer. By pruning them right after they bloom, maximum time is allowed before winter to develop the wood for next season’s flowers. If pruned during the winter or before flowering in the spring, flower buds are removed and blossoms are reduced or eliminated for the coming season.
Examples of early flowering shrubs in this category are barberry, flowering quince, cornelian cherry, deutzia, forsythia, holly, mountain laurel, privet or ligustrum, honeysuckle, magnolia, mock orange, firethorn, hawthorn, azalea and rhododendron, black jetbead, thunberg spirea, bridalwreath spirea, Japanese snowball, common lilac, Chinese lilac, French lilac, and viburnum.
Shrubs that flower after the end of May should be pruned in the winter or spring before new growth begins. They bloom on wood formed during the current spring or summer. Examples of summer-flowering shrubs are five-leaf aralia, glossy abelia, butterflybush, beautyberry, summersweet clethra, rose of Sharon, hills of snow hydrangea, peegee hydrangea, oakleaf hydrangea, crape myrtle, and hybrid tea rose.
Certain shrubs may be pruned lightly before and after flowering. This often increases flowering and fruit production and may result in a second bloom during the year. Examples of this group include glossy abelia, butterflybush, red twig dogwood, spreading cotoneaster, multiflora cotoneaster, Oregon hollygrape, Anthony waterer spirea, Frobel spirea, snowberry, and wiegela.
Ornamental trees that flower before the end of May should be pruned immediately after flowering. These include redbud, magnolia, flowering dogwood, hawthorn, crabapple, flowering cherry, flowering pear, flowering plum, horse chestnut, buckeye, serviceberry, fringetree, silverbell, witchhazel, holly, and chestnut.
Ornamental trees which flower after the end of May should be pruned in winter or spring before new growth or budbreak begins. These include golden rain tree, mimosa, Japanese pagodatree, sourwood, and other late-flowering trees.
Some trees, such as birch, yellowwood, elm, pine, spruce, fir, and maple, may bleed excessively if pruned in late winter to spring. Bleeding or loss of sap will not harm the tree but may be unsightly or messy. Bleeding may be reduced by pruning such trees when they are in full leaf (June).
Proper removal of branches is important. Care should be taken to neither cut too close nor to leave a stub. Cutting too close removes tissue that signals the plant to set boundaries for resisting the spread of disease infection. Leaving a stub will inhibit the formation of a boundary and result in decay spreading from the stub into the tree. For the proper removal of branches, all cuts should be made back to or just above a growing point. For example, remove branches just above a bud, above a side branch, back to a main branch or trunk, or back to the ground.
Your pruning equipment should be sharp because a clean-cut forms callus tissue to wall itself off faster and causes less injury to the tree. After the branch is removed properly, allow the tree to use its own defenses to protect itself.
Pruners and pruning saws are tools used to maintain shrubs and trees. The bypass type of pruning tools have a scissors cutting action that will cleanly cut the stem without crushing it. Pruning saws are designed to cut on the pull stroke. The blades are narrow to fit into tight spaces and still make clean cuts.
Hand pruners are best to cut stems up to three-quarters inch in diameter.
Attempting to cut larger branches risks making a poor cut and/or ruining the shears. Two-handed lopping shears can be used to cut branches up to 1 to 1.5 inches in diameter. Pruning saws are recommended for removing branches over 1 inch in diameter.
Be sure to disinfect pruning tools after pruning a tree with a disease by applying Lysol or 70% denatured ethyl alcohol to the blades.
For more information about pruning shrubs and trees, contact the Daviess County Cooperative Extension Service at 270-685-8480.
Upcoming eventA Beginning Beekeeping Class on Spring and Summer Beekeeping Activities is scheduled for Feb. 27 from 5:30 — 8 p.m. at the Daviess County Cooperative Extension Service Office. If you have any questions, please call 270-685-8480.
Do not apply paint or tar where a branch on a tree is removed. Research has proven that painting a tree wound is not beneficial and may actually do more harm than good.