The first thing worth understanding about pruning is that trees do not heal. They seal. A wound does not knit back together like skin. The tree walls the damage off and grows around it, and the wound stays inside the trunk for the rest of the tree's life. That is why the position and the size of a cut matter so much.
Start with the purpose
Pruning should only ever be done with a specific purpose in mind. Clearance from a roof. Removing deadwood. Reducing wind load. Building structure into a young tree. If you cannot name the reason for a cut before you make it, do not make it.
Every leaf you remove is photosynthetic potential the tree no longer has. Take too much and you have not tidied the tree, you have put it into deficit, and it will respond with a stress flush of weak growth that undoes the work.
Where the cut goes
Cut just outside the branch collar, the slightly swollen ring where the branch meets the trunk. That collar contains the tissue that does the sealing. Cut into it and you have opened the trunk. Leave a long stub and nothing seals at all, so the stub dies back and rot walks straight in.
On anything with weight, use a three cut method: an undercut first to stop the bark tearing, a top cut further out to drop the limb, then a clean final cut at the collar. Skipping the undercut is how you strip a metre of bark off a trunk in a second.
The minimum, always
The rule that has been handed down through this family, and that the standard now says in more words, is this: proper pruning can help a tree in many ways, but it should always be done with the minimum amount of live tissue removed. Less is almost always the right answer.
Not sure about a tree on your place? Send a photo. There is no charge for an opinion. Anthony, TreeX
