Scalping Injury

About Scalping Injury

Scalping happens when a mower cuts grass down to or below the crown — the growing point at the base of the plant where the shoots emerge. Once you cut below the crown, there is no green tissue left. The scalped area looks brown and dead, and whether it recovers depends entirely on when it happens. At 75 degrees in spring or fall, a scalped spot will recover. The crown is still alive, and the plant has enough growth energy and favorable temperatures to push new shoots. In summer, scalping kills the grass — the combination of mechanical stress plus heat stress plus the loss of all photosynthetic tissue is more than the plant can survive. The wider your mowing deck, the more aggressive the scalp can be. A wide deck can straddle a small hill completely, with each tire sitting on the low sides while the peak of the hill gets shaved down to the crown underneath the center of the deck. This is one of the most common ways mowing services accidentally damage fescue lawns in Middle Tennessee — the operator does not even realize it is happening because the tire wheels are on level ground. The fix is straightforward. Use a narrower mowing deck if your lawn has significant undulations. Roll out high spots with a heavy roller to reduce the peaks over time. Raise the mowing height — an extra half inch of buffer prevents most scalps. And remember the one-third rule: never remove more than one-third of the grass blade height in a single mowing pass. Scalping plus a violation of the one-third rule compounds the stress — the plant converts its deepest roots into carbohydrates to regrow the lost shoot material, losing the very roots that provide the deepest water access and cooling during summer drought.

Scalping Injury (N/A) is an abiotic disorder — a non-living, environmental cause of plant damage — commonly encountered in Middle Tennessee, including Columbia, Thompson's Station, Spring Hill, and the surrounding areas. This entry is part of our Abiotic Disorders Library.

Unlike diseases caused by fungi or bacteria, abiotic disorders cannot be treated with pesticides. Correct diagnosis is essential — our UT Certified Lawn Care Professional can evaluate your lawn or landscape and recommend the right corrective action.