Arborist InsightsPruningTrees

Katsura tree with too many leaves

By May 5, 2017 No Comments

“Every year this tree makes too many leaves.” That is a direct quote from the strata owner whose patio looked out on a nice Katsura tree specimen (Cercidiphyllum japonicum). I almost laughed. The tree makes too many leaves every year? Really? I talked to her politely and agreed that some thinning cuts were in order. But too many leaves? That deserved a blog post.

Thinning cuts

On a multi-stemmed tree like this one, thinning cuts are totally fine. Just pick a branch that rubs or crosses with others and remove it. You should be able to create some openings in the crown while still preserving a natural tree look. I didn’t have any trouble with this. It was easy to see crowded spots.

Just remember not to go too crazy. You can always come back next year. I made a few cuts on every tree and assessed it before taking more. And I will assess it again once the trees leaf out.

Too many leaves

This is a joke. Trees know what to do. We can’t tell them how many leaves to produce. What’s the big deal with leaves?

Trees use leaves as factories to make food from sunlight through photosynthesis. This is a free service which produces oxygen for us and removes carbon dioxide from the air. This process also releases water which affects local climate. Without leaves the tree can’t survive.

Once the food is made it is distributed throughout the tree. Upper branches can act as storage sites which is why pruning during drought can starve a tree. Under drought conditions, leaf openings called stomata close to prevent moisture loss. This, in turn, means that carbon dioxide can’t enter therefore food production stops. Then, here comes a landscaper with strata orders to prune trees. As he removes some of the upper branches, he removes food that was stored in them. Boom. Starvation ensues.

Leaves also serve as food for various animals and they act as cover for birds. For example, caterpillars munch on young leaves and are in turn eaten by birds.

Leaves also look great in the fall as they turn color. This katsura tree is no exception.

Too many leaves? Not likely. Let the tree do its thing.


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