Exposed tree roots can be frustrating. They interrupt lawns, create tripping hazards, and make mowing difficult. It is a common instinct to want to cover those roots with soil and replant grass to create a smooth surface. Unfortunately, adding soil over exposed tree roots often does more harm than good and can seriously compromise the health and stability of a tree.
Why Adding Soil Is a Problem
Tree roots are not buried randomly underground. The majority of a tree’s critical feeder roots live in the top 6 to 12 inches of soil, where oxygen, water, and nutrients are most available. When soil is piled on top of those roots, it restricts airflow and alters moisture levels, essentially suffocating them.
Even a few inches of added soil can cause long-term stress. Roots that are buried too deeply may begin to decline or rot, reducing the tree’s ability to take up water and nutrients. Over time, this stress can lead to thinning canopies, increased susceptibility to pests and disease, and in severe cases, tree failure.
Adding soil also changes the grade around the trunk, which can trap moisture against the bark. This creates ideal conditions for fungal diseases and decay, especially at the root flare where the trunk meets the ground. A healthy tree should always have its root flare visible.
Why Exposed Roots Happen in the First Place
Exposed roots are often a sign of natural growth rather than a problem. As trees mature, their root systems expand outward and upward. Soil erosion, heavy foot traffic, improper irrigation, or previous grading changes can also reveal roots that were always close to the surface.
Some tree species, particularly maples, oaks, and beeches, naturally develop shallow root systems. Trying to force these trees to conform to a perfectly flat lawn usually leads to ongoing maintenance issues and declining tree health.
What to Do Instead
Mulch Properly
A thin layer of mulch is one of the best solutions. Apply 2 to 3 inches of mulch over the exposed roots, keeping it pulled back from the trunk. Mulch protects roots, moderates soil temperature, and improves moisture retention without cutting off oxygen.
Adjust Lawn Expectations
Grass struggles under mature trees due to shade and root competition. Rather than fighting it, consider transitioning turf areas into mulched beds, shade-tolerant groundcovers, or naturalized planting zones.
Use Groundcovers Instead of Turf
Plants like mondo grass, liriope, sedges, or native woodland plants can coexist with surface roots far better than turfgrass. These options reduce mowing challenges while improving the overall look of the landscape.
Install Stepping Stones or Paths
If exposed roots are creating trip hazards, strategically placed stepping stones or pathways can provide safe access without disturbing the root system.
Consult a Professional Before Grading
If erosion or drainage issues are worsening root exposure, professional evaluation is essential. Improper grading solutions can damage roots and destabilize the tree.
Protect the Tree First
Mature trees are valuable assets that take decades to replace. Covering exposed roots with soil may seem like a quick fix, but it often leads to long-term decline. By choosing solutions that work with the tree rather than against it, you protect its health while creating a safer, more attractive landscape.
If you are unsure how to address exposed roots on your property, a professional assessment can help identify the safest and most effective approach.