Beetle pitch tubes

Pine beetle pitch tubes, which can damage trees if not handled properly.

I can’t believe fall is almost here. School is starting, the air is beginning to cool, football season will soon begin and, before you know it, your wife will be harassing you to go out and buy her pumpkin spice lattes again.

But while everything else seems to be starting up, your trees will begin shutting down to prepare for the cold months, making it an ideal time to prune. In fact, in our region, October-February are the best months to prune most trees. Here are a few reasons why:

Dormant trees are inactive during the cooler months. This means pruning will not counteract the necessary growth that happens during the spring flush and summer. It causes less stress to the tree, which allows for improved healing and more robust growth the following year.

Trees are also less susceptible to insects in the fall. Pine bark beetles (similar to our infamous emerald ash borers) are highly active during the warmer months. I’ve witnessed entire stands of red pines succumb to these nefarious characters. They attack fresh pruning wounds like teenage boys do pizza. It’s best to hold off on pruning pines until these brutal buggers pass their larval stage.

Additionally, diseases and fungi are generally less active in the fall. Oaks, for example, are far more susceptible to oak wilt, which rapidly kills trees, during the hot months. In fact, some municipalities west of us forbid pruning oaks until late fall to prevent the spread of oak wilt. Fireblight, which is a bacterial disease that affects apple and pears, is wildly active during the spring and summer. If you must prune during those months you literally need to disinfect your cutting tools between each cut. In the fall? Not so. The list goes on.

Now, in any discussion regarding pruning, I must always caution you, be careful. If you cannot reach your pruning cuts from the ground, search for “tree fails” on YouTube and discover why it’s never safe to cut trees from a ladder. You may want to consider hiring a professional, particularly an ISA certified arborist who has been trained in the science of pruning.

Mike White is an ISA certified arborist and owns Treemaster LLC. If you’re interested in learning more about pruning or any other tree related issues, you’ll find him to be moderately obsessed with trees. You can reach him at