How should I prune a weeping willow without shortening the life of the tree?

Question

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?

Pollarding is an attractive and historical approach – David LeBauer Apr 29 '12 at 02:35 — David LeBauer, Apr 29 '12 at 02:35
@David yeah, but I don't know what the people would think. – J. Musser Apr 30 '12 at 01:17 — J. Musser, Apr 30 '12 at 01:17

score 10 · Accepted Answer · edited Dec 26 '17 at 00:26

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:

Willows grow fast
they will bud from old wood, even really old wood
they are a messy tree, commonly dropping leaves and branches
they are used to breaks or cuts in the branch structure
willows have been coppiced for centuries. If that kind of hard pruning doesn't kill them off bad pruning is not likely to either. See here for a detailed discussion on pruning for look with willows

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.

The hedge trimmer at 7 ft could have the nice effect of pollarding — David LeBauer, Apr 29 '12 at 02:44

score 4 · Answer 2 · answered Sep 26 '12 at 17:43

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.

score 4 · Answer 3 · answered Jul 26 '13 at 12:36

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.

How should I prune a weeping willow without shortening the life of the tree?

3 Answers3