Pruning is an important part of garden maintenance, and often a vital role in a plant’s health. Removing dead, diseased, or crossing limbs keeps our branching friends strong and healthy. Not to mention, a tidied look enhances their natural beauty! The best time for pruning will ultimately depend on what type of plant you have. Take a look at our helpful pruning calendar to keep your trees and shrubs healthy and happy.
FALL
There’s something about the barren branches of fall that’s enticing to gardeners. With the leaves resting on the ground, instead of covering the tree, it may seem like the perfect time to do your shaping. However, pruning in the fall can often be detrimental to the tree, so leave your pruning tools in the shed and focus on the raking! Cutting branches of deciduous or fruiting trees in the fall may actually stimulate new growth. This forces the tree to use energy and resources for growth that it should reserve for its winter dormancy. The biggest exception to this rule is with Elm trees. Dutch Elm disease is a fungal disease, spread by the Elm Bark beetle. Trees are easily infected when they bare open wounds from pruning. Elm Bark beetles are most active during the spring and summer months , so it’s recommended to avoid pruning at these otherwise-popular trimming times. For this reason, pruning Elms in the fall or winter is acceptable. (Make sure to sanitize pruners with a 50-50 bleach/water solution to prevent the spread of disease between trees.)
WINTER
If you can’t prune in the fall, then surely our unpredictable Pennsylvania winters are out of the question, right? Actually, not quite! While we don’t want to send you out into the snow or freezing rain, pruning during dormancy is actually a common practice.
Pruning in late winter will prepare your trees for vigorous growth and blooming in the spring. Shrubs that bud in the spring and bloom in the summer, such as potentilla, will produce more branches and ample flowers after a winter trim. Winter pruning is especially important for sap-producing trees, as their open wounds are especially inviting to diseases like fire blight in the spring and summer.
SPRING
Pruning comes naturally to those who enjoy spring cleaning. The difference is that this time, you can actually act on your urge to tidy! Many spring-blooming shrubs bloom on the last year’s wood, meaning their buds are set during the previous summer. First, enjoy the beauty of your forsythia, lilacs, and rhododendrons, and then prune them just after their flowers fade. This ensures new growth before the summer, when next year’s buds will set.
While it’s best to prune fruit trees while dormant, you may need to prune damaged branches or remove overly abundant fruit to prevent damage to the tree. By culling some fruit, you’ll improve the quality of the remaining fruit, as it receives more energy and sunlight for the fruit to develop. Remember, though, that some fruiting trees, such as apples or cherries, flower on the previous year’s wood, so be careful when pruning.
Birch and maple can be safely pruned in the late winter, but if you want to avoid their sappy mess, you may also opt for a late spring/early summer trim. Be careful not to cut away more than a quarter of their open leaves, though. Any non-flowering shrubs or trees may be pruned at any time (except for fall, of course).
You shouldn’t have to wonder if you’re risking your plant’s health whenever you prune. With the help of our pruning calendar, you can confidently trim your trees with the knowledge that you’re simply maintaining their health and encouraging growth.