Lawn Care: Mowing around Trees

Because tree and grass roots exist together in the upper soil levels, it's important to understand that looking after one plant can actually damage the other. For example, applying fertiliser to trees is important for their growth, especially if they are fruiting trees, but the uptake of the fertiliser into nearby grass can result in greater and darker grass growth which looks very different to that on the rest of the lawn.

Some weed killers regularly used on lawns can damage trees if wrongly applied. Misapplication happens on windy days when drifting spray from the herbicide can fall on nearby trees, or alternately on very hot days when the weed killer may evaporate into the atmosphere, reforming as droplets on broad tree leaves. Always check the label before use.

Grass growing under or near trees should always be mowed at the highest recommended mowing height and it's a good idea, especially if using a strimmer, to trim back a large mulch ring around a tree, so that bare earth is showing. This means you won't be tempted to mow too close to the tree, damaging its trunk or root system, and also allows you to dump grass clippings, if you don't have a mulching mower, into the mulch space around the tree to feed it.

Watering trees and lawns together can be beneficial if done properly - on average, trees need around an inch of rain every 8-10 days and if you can match your lawn watering to this schedule, it will benefit both plants but over frequent and shallow watering can harm both.

Picture of grass and trees courtesy of Prakhar