In summer, healthy trees can start sealing off wounds from pruning cuts while continuing to put out leaves and make energy from sunlight. But if the tree is struggling with heat stress, summer pruning may be too damaging. The best time to prune is in early summer before temperatures have reached their peak.
Summer is an excellent time for restorative pruning. You can correct problems that have resulted from over-pruning or poor pruning. You can also clean up damage from winter and spring storms. Proper pruning will begin to restore most plants' natural shape.
A summertime shape up is healthy for people and trees alike. Although the best time to prune any plant is typically in its dormant phase, trees will benefit from a nice mid-season trim as well. Summer trims can cut down on the amount of pruning you'd have to do later in the year.
Few plants are pruned this time of year because pruning encourages new growth that does not have time to harden off before winter. Late-season pruning typically does more harm than good.
Pruning in August improves plant form just ahead of fall's growth spurt. Light shaping now will look beautiful after new fall growth arrives in the weeks ahead. Note: Plants should be well watered in the days ahead of pruning. Those that are experiencing drought stress should not be pruned.
Don't prune too late in northern regions.
In areas with cold winters, avoid pruning after the middle of August. If you prune too late, you may stimulate new growth that would not have time to grow thick, protective bark before the killing frosts of winter.
Don't Prune in Late Summer and Fall
Pruning shrubs in August or early September may encourage a late flush of growth. This new growth may not harden sufficiently before the arrival of cold weather and be susceptible to winter injury.
"They heal much better when we prune in the heat. They do recover quicker," says McCue, a master gardener for 10 years. When pruning a young desert tree, leave shoots growing low on the trunk for one year to strengthen it. Cut those shoots soon after to avoid creating a multi-trunk tree.
Helps Control Disease
Some trees, like oaks, should only be pruned during the dormant season because they are especially susceptible to oak wilt disease, which is known to spread extremely fast in the spring and summer.
Pruning to remove damaged, dead or diseased parts can be done at any time of the year. Most trees and shrubs, especially those that flower on current season's new growth should be pruned in late winter or early spring before the onset of new growth. (March-April).
Generally, the best time to prune or trim trees and shrubs is during the winter months. From November through March, most trees are dormant which makes it the ideal time for the following reasons: Trees are less susceptible to insects or disease.
The period between the full and new moon (third and fourth quarters) is best for harvesting, slowing growth, etc.
If you realize that your plant is root bound in the middle of Winter, it doesn't mean it's the right time to root prune it! All “invasive plant procedures” such as; repotting, pruning and root pruning need to be done in Spring, (Summer is OK too).
Prune shrubs that flower before mid-June after they flower. For these spring-blooming beauties, remove the largest stems, cutting them back to the ground. This causes the plant to push out new growth from both the crown and all remaining stems.
April, May and June are not good months to prune because deciduous trees need to use their stored energy to produce new leaves instead of healing wounds. Also, pruning during warmer spring months encourages the spread of diseases such as Oak Wilt and damage by pests such as Emerald Ash Borer.
When is the Best Time of Year to Prune Trees? There is never a bad time to remove dead, damaged or diseased branches. But most trees benefit from pruning in mid to late winter. Pruning during dormancy encourages new growth as soon as the weather begins to warm.
Cut too much and you'll risk nutritional deficiencies or branches that are too weak to tolerate the wind or fend off diseases or insect invasions. Over pruning and topping can permanently disfigure your trees, or even kill them. Further, a tree's foliage is important for protecting it against excessive sun exposure.
Trees are susceptible to stress just like any other creature, and removing their branches does cause damage to the tree. When the tree is dormant, however, less sap is lost and, since they are dormant as well, insects and fungus are less likely to further damage the tree.
Lack of foliage and large numbers of wounds will make your tree vulnerable to pests and disease. Over pruning can kill your tree over time. Although it's impossible to fix damage from too much pruning, there are some things that you can do to support your tree moving forward.
Overgrown trees can pose a serious risk to your property and your family. Dead or damaged branches can fall and cause damage to your home or car or even injure someone. In addition, overgrown trees can block sunlight and views and can even damage foundations or driveways.
According to gardening expert Mike McGrath, author of Mike McGrath's Book of Compost, and radio host of the show You Bet Your Garden, the rule of pruning is that you should NOT prune in fall. That's right, nothing and no exceptions.
If you want to prune in fall, wait until trees drop their leaves and are dormant—usually October or November. After leaf drop, you can see the tree's structure and identify disease and insect problems more easily.
Many commonly butchered shrubs and trees bloom in spring. This means that they've already formed their flower buds. So if you go crazy with the loppers and wail away on a spring-bloomer during the fall, you just might cut off the flower buds and that means no spring blooms.
An improper cut like a flush cut (cutting too close to the trunk) or a stub cut (cutting too far from the trunk) can cause irreversible damage to a tree. A flush cut removes the branch collar and leaves a large wound in the side of the tree that won't heal properly.