I prune a lot of neighborhood trees, but I've come to a small problem. Some people like their weeping willows high enough that they can walk underneath without brushing it. I have been doing this by hedge trimming the stems at seven feet.
Now I hear that this greatly shortens the life of the tree, as compared with an unpruned tree. Is this true, and if so, is there a better way to prune it?
Improper pruning can shorten a tree's life. However you would have to work really hard to damage a willow with bad pruning. Here's why:
If you continue to use a hedge trimmer at the seven foot level you will cause the tree to develop a mass of new growth at that height. It would be better practice and more aesthetically pleasing to use a pole pruner to deliver a series of graduated cuts at various heights. This will yield a wide band of new growth instead of a ribbon at one height.
Edit: @David You are right. Trimming with a hedge trimmer is essentially pollarding. However all the cuts are at the same height and, if continued for years, will produce a thick mass of branches. Traditional pollarding creates quite a different look.
I read somewhere to cut all branches that are under 6' from the ground off the main trunk. This allows for sitting under the tree. I am growing mine this way. I like the natural length of the branches. Perhaps this is something your client would consider. Just a thought.
I had a willow at my old house. From time to time we would just prune from the ground, reaching up as high as we could and clipping whatever branches (thin whips really) were hanging down. We did not notice thicker growth at that level from doing that. It looked nice, we could walk under it, and because it was on the front lawn, keeping the branches from dangling right to the ground meant more light in our house, and we could see the street.
We used to joke that the willow was self pruning because in any kind of storm it would shed branches onto the lawn like crazy.
