Maple trees—especially young, newly planted ones—are prone to winter sunscald. This injury appears as cracking or peeling bark on the southwest side of the trunk. It occurs when winter sun warms the bark during the day, followed by rapid nighttime cooling that damages the living tissue underneath.
Quick Sunscald Treatment & Care Tips
- Keep trees evenly watered through the growing season
- Mulch 2–3 inches around the root zone, away from the trunk
- Wrap trunks in late fall and remove wraps in early spring
- Protect stressed trees from borers in early spring
Watering & Mulching
Keep the tree evenly watered through the growing season. Water deeply during hot, dry periods and mulch 2–3″ around the root zone, keeping mulch a few inches away from the trunk.
Care & Protection
Do not peel or cut away damaged bark. The tree will compartmentalize the wound over time. Avoid pruning paints or sealants—they trap moisture, slow natural healing, and may increase decay. Wrap the trunk in late fall and remove the wrap in early spring to prevent further injury during winter.
Healing Expectations
Recovery depends on how much of the trunk circumference is affected:
- Less than 25% damage: Most trees recover fully with proper care.
- 25–50% damage: Trees often survive but may have slowed growth; protective care is important.
- Over 50% damage: Long-term health and structural strength may be compromised.
Fungal Growths
White, shell-like fungal growths may appear on areas already killed by sunscald. These fungi grow only on dead tissue and do not spread into healthy wood. Do not scrape them off. Focus on good watering, mulching, and overall tree health. If fungal growth covers large sections or appears on major limbs, seek professional evaluation.
Insect & Borer Protection
Stressed trees are more attractive to borers. Apply a systemic insecticide such as Ferti-lome Tree & Shrub Drench in early spring to help protect weakened bark. Follow label directions.
Fertilizing
Feed lightly in spring and again in November to support recovery and root strength heading into winter. Avoid heavy summer fertilization.
With proper watering, fertilizing, and consistent winter protection, most maples recover well from mild to moderate sunscald.