Pruning. It's not for idiots.

Pruning is a complicated subject. People have differing ideas on it. There are tons of different plants that do not follow the general rules. It's very easy to do it wrong. You have to know your plant. It also helps if you know a little bit of botany.  Anyway, I'm going to attempt to give you some basics on trees.

1. Trees don't heal, they seal. When you cut a branch off a tree, it does not heal itself. There will always be a "wound". The tree will do it's best to seal the wound, but it can't seal if the pruning is done wrong. A tree that has an open wound will be prey for pests, more vulnerable to weather, and can have structural weakness. Structural weakness is a big deal if you have a large tree next to your house in a wind storm. Trees with pests can be unsightly, annoying, and of course, die. Dead trees are sad.

2. Pruning for the purpose of shaping a tree, should be done slowly. Meaning, not all at once, and maybe even spanning across several seasons. If you want a specific shape for a tree, you also need to be consistent. If you can help it, don't let branches get really big before you prune them. Take care of an issue while the branch is small. The bigger the branch, the bigger the wound. Plus your tree will look weird for a while if half of it is suddenly missing. In my opinion, the best pruners, don't leave a large mark. A tree should look healthier with pruning, not butchered. Doing it at the right time, in the right way, your tree won't even notice, nor will your neighbors. As a general rule, do not prune more than 1/3 of a tree at a time.

3. Pruning away too much of a tree, wreaks havoc. We have all seen trees that have most every branch cut off, until there is basically just a trunk left. A trunk covered in wounds (Umbrella catalpas are the only tree, in my area ((that I'm aware of)), for which that is prudent).  A mature tree, that is suddenly stripped of all it's branches will not be able to sustain it's root system for long. It will try. It will try so hard that you will see tons of tiny little shoots springing up all around the cut in an effort to gain more access to photosynthesis. These little shoots, if left to grow will overwhelm the integrity of the branch. It will not be structurally balanced. All those little shoots will be coming up from the same angle, same spot, and compete with each other for space. That area will become a dangerous weak spot. Not to mention, the tree now looks hideous. Now if you have done this and are panicking, don't lose hope. With carefully timed pruning, and precisely the right cuts, there is a good chance you can save your tree. And with time, it might even get it's looks back. Just get someone who knows their stuff, to help.

4. The right cut in the right place is essential. For the tree to seal the wound it has to have it's collar intact. The collar is sometimes very visible, like a swelling at the trunk. Sometimes it's not, and you will need to make an educated decision. At this point, I think some pictures are necessary to explain better.


The collar is what will eventually seal off the wound. No collar, no seal. Bad. If you cannot see the collar, here is a picture with some math.




You'll want to make sure you fully understand this concept before you make a cut. It might take some practice. Err on the side of not cutting off enough. You can always add another cut, but you cannot put it back if you take off too much. If you took wood shop, you probably know this.

5. There is more to pruning than what I've shown here. These are just the basics of tree pruning.  It's also important to know which branch to cut off, what buds are, predicting new growth, when to prune, pruning for fruit, and lots more. But this seems like a decent start and my kids want dinner, so I'm out. I hope this helps.