If you are like many of us, trees and shrubs form the foundation of your landscape. In many cases these woody plants receive little attention from us other than making sure they are regularly watered. Occasionally, when they become overgrown or out of control we may attempt to rein them in by shearing them; often producing unattractive or dreadful results. Other times we simply pull them out and start over. The truth is that all of our trees or shrubs will benefit from regular pruning beginning with first year they are planted.
Pruning is important to the health of your trees and shrubs; when you remove branches that are dead or dying as a result of disease, severe insect infestation, damage from animals or storms or branches that are rubbing against each other. Pruning will also encourage new growth and flower and fruit production. Another reason to prune is to improve the appearance, maintain the size or shape and/or the original purpose of your woody plants. You may want to remove unwanted branches or suckers, control the size of your plant and/or maintain its nice – but natural – shape. You may wish to prune trees or shrubs that obscure the entry to your home, cover your windows or you may be required to trim ones that obstruct the vision of drivers or pedestrians. However when a tree or shrub is pruned properly you should not be able to tell that it has been pruned.
Late winter and early spring are commonly the times for pruning most shrubs. In general you should prune out diseased and broken branches in late March or early April during cold weather while the plant and pathogens are dormant. This reduces the time the bare wound is exposed before the plant begins new growth and healing. However refrain from any additional pruning of the shrubs that flower in early spring such as azaleas, rhododendrons, forsythias, lilacs, magnolias or early blooming spireas. These should not be further pruned until after they have bloomed unless you wish to forgo the flowers for this season. These flowering shrubs have set their buds the previous summer and fall on last year’s growth. Pruning healthy live branches of these shrubs will cut off their buds.
Shrubs that bloom later in the summer or are grown primarily for their foliage such as barberry, burning bush, dogwood, honeysuckle, ninebark, smoke bush and sumac should be pruned before the new growth starts in late winter or early spring. Plants that bloom on new growth in the spring, such as clematis and shrub roses, should be pruned at this time as well by cutting back to live wood. Later blooming spireas and hydrangeas can be cut down to above the first buds above the ground. This will lead to vigorous stem growth that will form buds that open in summer or fall.
Thinning is one method of pruning, especially effective for shrubs that produce multiple stems from the crown. Removing a few of the oldest and largest stems at the ground annually encourages new growth and flower production while maintaining the natural shape. Never remove more than 1/3 of the stems in one year so that enough foliage will remain to support new growth. New growth on deciduous shrubs usually occurs at the ends of the branches. Trimming the ends encourages side shoots, producing a bushier and fuller shrub while controlling size. Branches can be trimmed back to within 1/4” of a larger branch or bud. “Pinching” is removing just the bud tip to encourage side shoots, especially effective in helping young shrubs to fill out. Shearing is removing all new growth usually used to maintain a formal shape or a hedge. When shearing you should always leave at least 1” of the previous growth so the shrub can start new growth.
With attention to pruning you can maintain the shrubs in your landscape for many years to come. You can learn more about pruning from a certified arborist at the Victory Neighborhood Associations Spring Garden Workshop on Saturday, April 7 at Webber Park beginning at 9:30 a.m. All are welcome.