Mulching trees to stop grass growth


The trees we planted back in February are doing well, but the grass has been growing a lot because there aren’t any sheep in the field anymore. Left unmanaged, the grass would grow very tall and possibly impede the growth of the trees. We’ve had two sprays of glyphosate herbicide on the grass around the trees to keep it down, but I don’t like spraying too much because of the adverse impact it might have on the rest of the ecosystem, and the risk that it might damage the trees. Also, although the herbicide kills the grass, the dead grass doesn’t disappear. I wonder what effect this build up of dead grass will have on what grows there next year. As a more long term solution, I’ve been mulching around the trees with wood chips. This is very labour intensive, but it’s clear from observation that an application of mulch is much more effective than spraying over the long term.

The effects of glyphosate herbicide on the grass

First, the grass has to be cut around the tree, so the mulch will sit and not slide off. I’ve been using long-handled garden shears to do this. This is the part of the process which takes the most time.

A freshly cut area of grass around a tree

Then, the mulch can be added around the tree. I’ve been making a layer about 2-3 inches thick. It’s important that the mulch isn’t piled up around the tree, because this can encourage fungal diseases at the base of the tree.

An application of mulch around a tree

I’ve been noting down on my new stem map which trees have been mulched, so I can see whether it decreases mortality over the next few years.

Using the Kawasaki Mule to transport the wood chips has greatly reduced the amount of labour, as it can drive down the rows of trees, which are only 2.5 m apart.

Wood chips in the back of the Mule