Maple Trees & Sun Damage
Although it seems impossible, maple trees can be damaged by the sun. Sun scald is likely during the winter months when the weather is dry and the maple tree is weakened to the elements. Bark temperature that sinks low will kill active tissue in the tree, making sun scald a reality.
Sun scald is indicated on a tree's bark by long, sunken areas of dead bark that will appear cracked or dead. During the winter, the sun may heat the bark. When temperatures drop suddenly, during a snowstorm or when a cloud passes, the temperature drops again, causing the bark to break apart.
Newly planted maples and maples that are left unprotected from sun require wrapping with a commercial tree wrap, plastic wrap or light-colored material to reflect heat and sunlight. Wrap application is needed in late fall when the temperatures begin to drop. Removal after the last frost in the spring prevents bark from sinking inward.
Sun scald should be removed using a sharp knife. Damaged bark cut away following the shape of the scald will prevent rotting and disease infection. Corners of the wound require rounding off to remove all incidences of burn. Wound dressings may cause moisture collection, so wounds should be left naked. Spraying fungicide inside the wound prevents infection.
Leaf scorch is a condition where the foliage on the tree turns yellow, then brown. This is caused by dry winds or periods of intense sun, then cooling. Water is drained from the leaves faster than they can be replaced, making the leaf die. Unfavorable growing conditions such as exposure and dry soil make the sun damage worse.
Leaf Scorch Control
Leaf scorch, once visible on the tree, has already run its course. Preventive measures are possible to prevent further, more serious damage. Deep watering of the maple roots will prevent water loss, especially during dry winters. Slow-release fertilization in the fall, around September, will provide the right amount of nutrients for the maple throughout the winter.