Although most roots tend to grow (and stay) underground, sometimes those belonging to trees can make their way to the surface. This is not something you see out in the woods, unless you are walking along a trail and stumble upon some. However, it is possible for tree roots to emerge from your lawn.
Here’s what to do–and equally important, what to avoid–if you have visible tree roots in your lawn.
Officially, these are known as “surface roots,” and if they’ve emerged from underground and spread across part of your lawn they not only pose a safety hazard (providing something else for people to trip over), but they also make it difficult to cut your grass. What’s the deal with these roots? And why are they not on the right side of the ground, according to
Diana Alfuth, a horticulture educator at the University of Wisconsin-Madison’s Agriculture Institute, most large, mature trees can develop surface roots, but it’s especially common in species like poplar, willow and silver maple.
Typically, most of a tree’s roots grow horizontally in the top four to 15 inches of the soil, allowing them to remain protected underground, but close enough to benefit from the oxygen that permeates the surface of the soil. The roots will eventually move closer to the surface when the soil becomes dense, heavy, or does not drain well.
“Each year a tree’s roots get thicker, just like the trunk does, and eventually they can break the surface and be visible in the lawn,” Alfuth writes. “Erosion of soil over a root system is another cause of surface roots.”
Avoid doing anything that will damage a tree’s roots, including:
- Attempting to dig them up
- Cutting, chopping, or pruning them
- Using a rototiller on them or the adjacent areas
- Running them over with a lawnmower or tractor
If you are adamant about reclaiming that area for your lawn, the key to making it possible is protecting the tree’s surface roots. One way to do this is to spread a shallow layer of topsoil around and over the exposed roots–enough so they’re covered by about a half inch of dirt.
Be careful not to cover the surface roots in too much soil, though–that can end up suffocating the tree, either damaging or killing it. Keep in mind that the tree’s roots could grow back to the surface and you will likely need to do it again.
You can also stop trying to grow grass in that part of your yard, and cover the area in mulch or wood chips instead. Another option would be creating a clear border around the surface roots using larger rocks or bricks, and letting the roots do their thing.