Question

Mr. Hyland,
We have a Japanese Maple about 3 feet tall, approx. 9 years old that has been doing generally well.  It is planted in full sun in southern Michigan.  Each year during the heat of the summer the ends of some of the leaves turn brown and curl upwardly inward.  This year almost ALL the leaves are exhibiting this problem/disease, and somewhat earlier in the summer than in the past.  I have searched upper surfaces of the leaves as well as underneath and can find no evidence of insects or canker spots.
Any suggestions?  Many Thanks.
John

Answer
The symptom known as leaf scorch results when the roots are unable to supply enough water to replace that used by the leaves. For this reason scorch is most commonly seen following dry spells, drought, or on windy sites.

The most common pattern of leaf scorch is a drying out and browning of the leaf margins  The symptom is often more severe on outer, more exposed leaves, especially on the sunward and windward sides of the tree.

Where hot drying winds occur for several days during the period of active tree growth, more severe scorch symptoms may appear. The outer parts of leaves or whole leaves dry up. Following such an episode new leaves will often form if moisture supplies to the roots are adequate.

Where hot drying winds occur for several days during the period of active tree growth, more severe scorch symptoms may appear. The outer parts of leaves or whole leaves dry up. Following such an episode new leaves will often form if moisture supplies to the roots are adequate.


Conserve soil moisture by mulching trees and shrubs with rotted leaves, bark, or other material. And if watering is necessary, be sure to water thoroughly because mulches absorb water from the surface. Light waterings will do no more than wet the mulch.