When to Prune Trees and Shrubs
July 20, 2017
When trees and shrubs become overgrown, it’s time to break out the pruning shears. With this guide, learn when to prune trees and shrubs to get the most out of your plants, and why pruning is such an important part of garden maintenance.
Why prune trees and shrubs?
Plant health is the primary reason for pruning. Look for the 4 “Ds”—dead, dying, diseased, or damaged branches—these should be removed. Also look for spindly or weak growth, as well as any branches that are crossed or rubbing.
Safety is another important issue. Low hanging branches can be eye-pokers and get in the way when you are trying to work or play around a shade tree. Pruning these branches is called “limbing up.” Not only does it encourage top growth, it also makes room for you to safely enjoy the area under the tree. If your trees have any weak, dangling branches that could break off unexpectedly, they pose a danger to people, cars, buildings, and valuable plants underneath. If these branches are high up in the tree, very large, or near power lines, it is best to call in a professional tree trimming company.
Often, a plant needs pruning to control its size and keep it in bounds. Overgrown shrubs can be brought back to scale, large shade trees can be reduced enough to cast less of a shadow, and fruit trees can be kept to a reasonable size, making care and harvesting easier. Hedges can be maintained at the desired size and shape. Water sprouts (small, spindly branches) that grow straight up from the limbs of a fruit tree will not bear fruit and should be clipped off as they develop.
When to Prune Trees and Shrubs
When to prune trees and shrubs is a hot topic, and it’s no question that spring is the ideal time to inspect your trees and shrubs for winter damage. It is much easier to see the structure of deciduous plants without their leaves, so pruning can be accomplished quickly and easily. Most trees are still in a state of dormancy and will bleed less sap, and insects and diseases are less active.
The basic rule of thumb is to prune spring-flowering shrubs right after they bloom in order to avoid cutting off next year’s buds. Shrubs such as forsythia, lilac, star magnolia, mock orange, azalea, rhododendron, mountain laurel, dogwood, sand cherry, quince, and andromeda develop their buds on old wood—branches that grew last year. If you wait until after they bloom, you can deadhead and prune at the same time. This will encourage lots of new growth and give you more flowers next year.
Shrubs that blossom late in the summer, such as Hydrangea paniculata, rose of Sharon, clethra, and buddleja set their buds on new wood. They often bloom best if they have been cut back while dormant in late winter to encourage more new wood to form. When thinning deciduous shrubs, remove the oldest, tallest growth first and then take out weak or spindly stems. For renewal pruning on multi-stemmed shrubs, such as forsythia, lilacs, or viburnum, take out 1/3 of the oldest stems each year to encourage new growth.
The art of pruning is a skill that you can develop over time. Don’t be afraid to experiment and learn as you go, and don’t hesitate to consult a good book on the subject or check with your county extension office for information on pruning specific plants. By knowing your plant, its purpose, and especially when it blooms, you will be able to prune it correctly.
About This Blog
Get inspired by Robin Sweetser’s backyard gardening tips and tricks. Robin has been a contributor to The Old Farmer’s Almanac and the All-Seasons Garden Guide for many years. She and her partner Tom have a small greenhouse business and also sell plants, cut flowers, and vegetables at their local Farmer’s Market.