August is an excellent month for pruning many shrubs and trees in the landscape, just ahead of the fall growth spurt. It's also a perfect time for pruning backyard fruit trees for size control. Removing excess growth now instead of waiting until January will help keep fruit trees smaller.
Pruning and training
Prune wisteria and climbing shrubs such as Pyracantha after flowering. Hebes and lavenders can be given a light prune after flowering. Rambling roses can be pruned now, once they have finished flowering. Give hedges a final trim over now.
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.
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.
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.
Late summer or early fall pruning causes vigorous re-growth of tissue, which in some cases may not harden off by the time winter arrives, leading to possible cold damage to the new growth.
Pruning Trees in Summer: Cut Conservatively
If you prune to excess in summer, next year, your trees may not be as full. Summer pruning takes away from the tree's total number of leaves, and fewer leaves mean less food flowing throughout the tree for next year's growth.
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.
The best season to prune trees is while they are dormant, or generally between November and March. This means waiting for them to lose their foliage and cease growth, but before forming buds. For fruit trees such as the apple tree, prune in late winter.
If you've got a fruit tree, summer pruning will promotes more blossoms (and more fruit!) the following spring. Fruit will mature better in sunlight, so allowing air and sun to reach the fruit will boost its size and sweetness.
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.
Did you know that if you prune too late in the season, you stimulate new growth, which will not have time to harden off before the first frost, which will be coming soon to our neck of the woods. This can weaken and damage the plant, so its best to leave the pruning until spring.
Choose the Right Time
Likewise, prune in the early morning or late afternoon to avoid the newly cut ends of branches becoming scorched by the hot sun. Wait 48 hours after rain to prune, to allow plants to dry out and avoid fungal diseases. When pruning, make cuts just above leaf nodes, or buds.
Summer pruning is best done in August-September, when the majority of branches have set a terminal bud.
Pruning in summer may encourage vigor. In summertime, weak tree growth should be pinched or pruned back about 3 inches from the end of each soft, leafy shoot. This can be repeated again in late summer if rapid side-shoot growth occurs.
By not cutting back the statuesque achilleas, eryngiums, perennial astilbes, sedums, alliums and many ornamental grasses, you can enjoy their structure against a winter sky. The sight of their stems silvered with frost adds a whole new level of interest to the garden.
The rule on fall pruning is, generally speaking, don't prune in fall. But there are a few trimming tasks you can take on with confidence, provided you approach the job with self-control and a plan. The timing window for these pruning chores is from Thanksgiving to the New Year.
In early fall, pruning wounds close more slowly and plants are more at risk for fungal diseases than at other times of year. For most trees, the best time for major pruning is late winter to early spring because wounds close faster.
DON'T prune during fall.
This can weaken and damage the plant—especially if there's an early frost.
Don't shear the branches of spring flowering shrubs (Forsythia, Lilac, New Mexico Privet, Spirea, Flowering Quince, and others). These shrubs produce flowers on last year's wood, so removing old growth will reduce or prevent flowering. These plants should be pruned immediately after they are done blooming.
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.
As a general rule, prune spring-blooming trees immediately after they flower. Prune trees that bloom in the summer or fall in late winter or early spring before the end of their dormancy. Routine pruning of dead or dying branches can be done at any time.
Summer pruning involves cutting back new shoots to allow light to reach the fruit. New shoots are stiff and woody along their bottom third, with dark green leaves and a cluster of leaves at the base.