Everyone has experienced the unpleasant klunk and jerk associated with running a lawn mower over an exposed tree root. Hey, how sharp does that blade even have to be, right?
But exposed tree roots are more than just a problem for your mower blade. Tree roots don’t just rise up out of the soil like tentacles. The soil erodes away from them for a variety of reasons.
How Tree Roots Become Exposed
Most people are not aware that most tree roots live right underneath the surface of the soil where the moisture and nutrients are most plentiful.
As the tree grows, those roots become bigger and thicker. In some cases, they grow so large they do rise above the surface. Maples, for instance, are rather notorious for this. But usually what happens is that the grass under the tree gets too much shade, and also competes heavily with the tree’s roots for water. This results in a no-win situation for the grass, and eventually it starts to fail.
The trouble is, the thick network of grassroots, combined with the dense thatch from the lawn clippings, is mostly what keeps the topsoil intact. As that stuff breaks down, the topsoil blows or washes away, leaving naked tree roots behind.
How to Handle Exposed Tree Roots
Despite what you might think, it is not the best plan to simply add a bunch of dirt over the roots. For one thing, this makes your lawn even lumpier. For another, without the grass to hold it there, it will soon wash away as well.
You could try reseeding, but it’s unlikely to catch, since the problem that killed the previous grass (ie, the tree) still exists. So the best thing to do is to mulch.
Yup. For once, the best thing to do is also the easiest. Rather than babying spindly grass seedlings, you can dump a bunch of mulch in a neat circle and never have to mow there again.
The best mulch is technically pine straw (dead pine needles) but it’s not terribly easy to find commercially, although you could ask your neighbors. The reason it’s good is because it lets the moisture through. A mature tree doesn’t need any help keeping moisture sequestered, and sponge-like mulches could potentially harbor mold.
But, if you can’t find pine straw, double shredded mulch (in a relatively thin layer) or bark nuggets (in a thicker layer) are acceptable alternatives.
Never feel that sickening thunk-crunch again!