Pruning at this time of year will severely weaken the plants. This is disastrous for the plants and all the hard work you did during the year to make your landscape beautiful.
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.
Pruning evergreen bushes is best done in late March or early April before new growth begins. Light pruning can also happen in late June or early July. Avoid pruning evergreen shrubs in the fall, since they are more 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.
Do not prune deciduous shrubs in late summer. 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.
Late spring, early fall, or winter (when the hedges are fully dormant) are the best times for pruning hedges. Don't prune hedges during very hot, dry weather, and prune well before your first frost date.
Prune all evergreens, except pine, before new growth starts in the spring or during the semidormant period in mid-summer. When pruning, follow the general branching pattern to maintain the natural shape. Remove dead, diseased, or broken branches anytime.
Using a sharp hedge trimmer, shear back up to three inches of new growth. Shearing annually will maintain shape and form and is also a technique for controlling size. Using a sharp hand pruner, cut off one half the length of all new candles in early spring. Tip pruning will encourage dense growth for a full plant.
DON'T prune during fall.
No matter what type of shrub you have, fall pruning can stimulate late-season growth that may not have enough time to harden. This can weaken and damage the plant—especially if there's an early frost. Instead, wait until winter and trim bushes when the plant is in deep dormancy.
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.
Winter is usually the best time.
If you live in an area with distinct winters, the time when shrubs have lost their leaves and become dormant is an excellent time to prune them. Without the leaves, you can easily see the branching structure of the shrub and decide what to cut.
You probably already know just how fast shrubs grow and start to look messy. If you wait too long, your shrubs will start to become an eyesore. Pruning less of the plant but more frequently is by far the best for the overall health of it. We recommend every other month, which comes out to be five times per year.
Rejuvenation pruning is typically done only every three to five years, usually when the shrub starts to look overgrown or stops flowering. Cutting off all the stems and leaves is a huge stressor to the plant so it's best not to do it too often.
One surefire tip: don't prune evergreens in late summer or fall. Pruning late in the growing season leaves plants susceptible to winter damage. The calendar isn't a factor when cutting out dead, broken, or diseased evergreen foliage.
Large evergreen trees do not respond well to topping. The removal of the upper main stem through topping opens the tree to internal decay, disease or damaging insects; it also removes the most productive portion of the tree.
Pruning Too Early
If you prune too early in the season, there's a good chance you'll snip the buds right off their branches, which means no flowers in the spring. Before you cut, do a little research, like with our pruning guide, or just wait to trim until the plant has finished blooming for the year.
Late winter or very early spring is best, to avoid trimming the hedge during its peak growing season. Always try to cut a hedge back after the flowering season. Getting the timing right will ensure that when you do cut the hedge, the shape will remain visible for longer.
What are the most popular evergreen shrubs? Some of the most common evergreen shrubs include arborvitae, boxwood, false cypress, holly, juniper, wintercreeper, azalea and rhododendron.
Plants are more brittle in cold temperatures. Messing around with them may cause branches to snap and split unintentionally. It's minor, but it could impact the look of a plant or create a haven for insects and diseases later. Don't prune when the temperature falls below 25°F.