Lawn Mower Damage to Red Maples: Assessment and Care

Circumferential bark damage from lawn equipment is a leading cause of young tree decline. The bark at ground level on your 9–11-year-old red maples has split and sloughed off—this is mechanical girdling.

Assessing Survival

• Partial girdling (damage <50% around trunk): Tree can survive with care.
• Full girdling (bark lost all the way around): Tree will die—phloem (food transport) is severed.
• Lichens and insects are secondary colonizers, not the cause.

Immediate Care

1. Stop mower damage: Create a 3–4 ft mulch ring around each tree.
2. Water consistently: 1 inch per week (use a pan to measure). No fertilizer.
3. Do not paint/wrap wounds—research shows this traps moisture and delays healing.
4. Monitor for borers: Stressed trees attract them. Spray trunk with permethrin or bifenthrin in spring if you see sawdust or holes.

Professional Evaluation

Contact the Alabama Forestry Commission (Derrick Heckman, Springville office) for a free on-site assessment. They can determine girdling extent and long-term prognosis.

Trees with partial damage often survive for years but remain stressed. Prevention—mulch rings and careful mowing—is the only real cure.