Answer: Roots surface as they grow in diameter, forcing what was a thin, shallow root above the surface. They also surface as erosion washes away soil, exposing the roots. This exposes them to significant damage from lawnmowers.
There is no way to stop roots from surfacing, unless it would be a matter of redirecting water causing soil erosion. The best solution is to add soil to the area beneath the tree where the surfacing roots are found. If you are covering a considerable portion of the area beneath the branch spread, about 2-3 inches of soil is all you should add the first year. More can be added next year if needed. If only small areas are to be covered, you can increase the amount of soil added the first year.
If you have St. Augustine grass growing under the tree, several inches of soil will likely kill it. You can either add soil and then resod, or add soil in small amounts (approx. 1/2 inch at a time) beginning in spring when the turf is actively growing. Allow the turf to recover and then add more.
Thanks for the question!
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