Scorch (leaf)
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Scorch (Leaf)
 Leaf scorch can be caused by many adverse environmental conditions, including soil compaction, transplant shock, nutrient deficiency, drought, salt toxicity and herbicide injury. Leaf scorch is common in the Northeast United States due to cold soils and slow root growth. The loss of leaves is seldom immediately fatal, but conditions causing leaf scorch should be corrected if possible over time, they can cause the decline or death of the tree or shrub. Plants under stress are subject to secondary problems such as attack by insects or diseases. Susceptible Plants- include horse chestnuts, maples, and wide range of woody and herbaceous plants. Symptoms- of leaf scorch due to environmental causes include browning of the leaf margins and yellowing or darkening of tissues between the main leaf veins. As the condition progresses, entire leaves may dry up, turn brown and become brittle. Leaves sometimes wilt rapidly, usually remaining a pale green color even when dried out. Damage is usually more pronounced on the upper, windward or southern side of trees. Plants may lose many leaves prematurely during late summer and exhibit some twig dieback. Prevention and Control- To help prevent leaf scorch, prune sprouts and diseased areas. Maintain vigor through proper watering and fertilizing. Water deeply to encourage deep root systems that enable trees to withstand environmental stress such as drought and winter desiccation. Check soil moisture at least 12 inches down--if it is rather dry, water trees slowly and deeply, allowing water to penetrate at least two feet. Deep-water the entire area under the canopy, one and one-half to three times farther than the branches--95% of the roots of most trees, including tall evergreens and large deciduous trees, is found in the top 18 inches of soil in this extended area. Sufficient moisture will help keep the trees vigorous enough to withstand pest attacks, as well as help prevent winter injury. It is very important to deep-water trees and shrubs at least twice a year, especially in areas where the water table is far below the soil surface or on sites exposed to wind; water every fall, after leaves turn autumn color but before the ground freezes, and again in spring as soon as the ground thaws to replenish dehydrated roots. Trees suffering from drought can be selectively pruned to reduce transpiration (the loss of water due to evaporation through the leaves). Drought occurs when transpiration exceeds the plant's ability to supply water through the roots. Avoid frequent, light watering as well as watering only at the base of the tree trunk helps prevent leaf scorch..
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