September always feels like a season of transition. School has started back up, football games are back to being a weekly weekend ritual, and I am looking forward to cooler weather even though that may be weeks away. In the landscape, it’s also the time when many homeowners look at their yards and get the itch to tidy things up. Shrubs may be shaggy, trees have low-hanging limbs, and spent blooms tempt you to reach for the pruners.
But before you start cutting, it’s worth knowing what pruning in September really means for your plants. According to Texas A&M AgriLife Extension, the timing of pruning can make a big difference in plant health and next year’s performance.
Heavy pruning even now carries some risk. September in East Texas often brings a mix of lingering heat and the occasional early cool front. When you make big pruning cuts late in the growing season, you stimulate tender new growth. The problem is that the large limbs are helping roots have enough stores for the winter. Conversely, pruning now could stimulate new shoot growth that may not have time to harden off before our first frosts arrive. This leaves plants vulnerable to cold damage and stress going into winter.
That’s why AgriLife experts and others across the country recommend saving most major pruning for the dormant season—late winter through very early spring. During dormancy, plants aren’t actively pushing out new growth, and wounds can heal quickly once spring growth begins.
But what about those dead limbs or that one limb that hits my car when I pull in the drive? Light, corrective pruning is always acceptable. This includes removing dead, broken, or diseased branches. Also cutting out limbs that are rubbing or crossing each other. And certainly, eliminating water sprouts or suckers at the base of trees.
For ornamental trees like crape myrtles, it’s fine to snip off old flower heads if you want to improve appearance. Just resist the urge to make large heading cuts – what some call “crape murder.” Save reshaping or thinning for winter.
Fruit trees should also be left mostly alone at this time. The fruit tree’s current leaf canopy is helping the roots store up for a productive spring emergence. While light thinning for air circulation is okay, the major pruning that shapes peaches, plums, and pears is best done while they’re dormant.
The most important pause should be on any of your spring blooming shrubs. Shrubs like azalea, camellia, spirea, and hydrangea set their flower buds the summer before their next spring’s bloom. If you prune them now, you’re not just removing ragged growth—you’re cutting off next year’s flowers. For those plants from which you want (and expect) the most blooms, even dormant season pruning would be a huge mistake. Hold off until right after they finish blooming in spring before doing any shaping.
Below are some helpful tips that research and seasoned gardening experts suggest. First, use clean, sharp tools to reduce injury and prevent disease spread. Next, make cuts just outside the branch collar (that swollen area at the base of a branch). This helps the plant seal off wounds naturally. Finally, as you are pruning, step back often to avoid over-pruning—it’s easy to take too much without realizing it. Your pruning decisions will shape your trees and shrubs for years to come and require careful evaluation.
September is a month for restraint with your hand pruners and loppers. Go ahead and clean up diseased branches or low hanging hazards but hold off on the major shaping until winter. By pruning with the seasons in mind, you’ll set your trees and shrubs up for better health and stronger growth in the years ahead.
