WHAT IS LAWNMOWER BLIGHT? HOW CAN YOU PREVENT IT?
If you've never heard the term "lawnmower blight" before, you might be guessing it's something that affects your lawn. But it's not. Lawnmower blight has to do with your trees, and it can shorten their lifespan and make them more susceptible to disease and pests.
So what is lawnmower blight? And how can you avoid it?
Lawnmower blight is the injuries that trees sustain around the base of the trunk from being repeatedly rubbed by the edges of a lawnmower or from the strings of trimming blades of a lawn trimmer.
While we can compare the bark of trees and shrubs to our skin, in that it protects the tree from the elements like skin does, it does not heal the same way. Our body generates new skin cells to heal over injuries, leaving a scar sometimes. When a tree develops a wound, the bark cannot regenerate new bark cells to replace the damaged ones. If a section of bark is removed or damaged, it opens up the tree's body to the weather, pests, and diseases.
Bark protects all the inner layers of the tree, the phloem, cambium, xylem, sapwood, and heartwood. Each of these different layers is important to the health of the tree. The xylem and phloem layers transport nutrients and water in sap, up through the tree and out to the branches and leaves. If the bark is damaged, the cells in that area die, and the flow of the sap is interrupted.
Repeated damage, even just a small wound, could eventually cause the tree to die prematurely, either from the tree's inability to transport sap or because it may get infected with a disease or infested with pests at the site of the wound.
HOW DO TREES GET LAWNMOWER BLIGHT
Lawnmower blight happens when the lawnmower's metal edges or strings of your lawn trimmer repeatedly rub or hit against the trunk of a tree in the same spot. It can also happen if a lawnmower mows over an exposed section of a root.
Trees are particularly susceptible to damage when they are young, especially in the spring, when they're just starting to put out new growth. The worst part about lawnmower blight is that the injury site is usually injured repeatedly because we have to mow our lawns pretty frequently in Indiana. If the wound goes all the way around the tree, which is common when removing weeds with a lawn trimmer, it can kill the tree super fast, as it stops any sap from being able to get up the tree at all.
HOW TO PREVENT LAWNMOWER BLIGHT
It's essential to be careful when mowing around your trees so that you don't injure them, especially when they're younger. It's important for whoever is responsible for mowing the lawn to understand what causes lawnmower blight, so they can avoid causing it.
There is an easy way to keep your trees safe: simply give each tree a thick layer of mulch or decorative gravel over the root area. The mulch will keep lawnmowers a safe distance away from the trunk and roots of your tree. Mulch also has other benefits for your trees, like helping to retain soil moisture, and regulating soil temperature.
It may still be tempting to use a lawn trimmer to remove weeds and suckers around the base of a tree, but it is much safer to remove them by hand. Once your tree is more mature, weeds will have a harder time growing under it due to the tree using up the majority of water in the area, and blocks out most of the sun.
Trees are an investment in your landscape. Don't let careless mowing destroy your investment. When your trees are young, a little careful TLC will help them grow strong and healthy, to keep your yard beautiful for years.