Why Winter Is The Time To Trim Most Trees
If your tree has a limb that's dangling and about to break, you can trim that off regardless of the time of year. Similarly, if a tree has storm damage, prompt trimming is usually appropriate. However, if the need for trimming is not so immediate, winter is usually the best time to have a tree trimmed. Here are a few reasons why.
Less sap is flowing.
Trees use a fluid called sap to deliver nutrients and water up to the branches and leaves. This sap runs quickly in the spring and summer when the tree is actively growing. (The tree's tissues need more water and nutrients to grow.) If you trim a tree when the sap is really flowing, a good deal of sap will leech out. While this won't be life-ending for the tree, it is a waste of resources. If you can instead wait and trim the tree in the winter or early spring, the sap will be thicker and won't be flowing as readily. So, the tree will lose fewer resources when you trim it.
Fungi are not as prominent.
Fungal infections are a big concern for trees. Some, like anthracnose, are rather minor, but they still make a tree look ugly as they cause spots on the leaves. Others, like oak wilt, will kill the tree within a few years. You want to protect your tree from fungal diseases, and trimming in the winter helps do that. There are far fewer fungal spores floating around in the winter, so your tree's trim wounds are far less likely to become infected. If the tree you're trimming already has a fungal disease, trimming it in the winter can help prevent the disease from spreading to other branches.
You're not removing new growth.
Imagine being a tree and putting lots of resources towards growing new branches, only to have those branches removed a few weeks later. This is what you're doing if you trim a tree in the spring or summer. If you instead trim in the winter, you won't be removing that new growth. Rather, you'll be removing less viable branches so your tree will have even more resources to dedicate to new, healthy growth when spring comes.
If it's an emergency, trim your tree regardless of the time of year. But in non-emergency cases, trimming in the winter or very early spring, at the latest, is the way to go.
Contact a local tree trimming company to learn more.