Answer: Maples are prone to leaf scorch which is a cultural problem rather than a disease. Daconil is a fungicide, which will prevent fungal infections but won't correct the problem of drought or heat stress. Instead of treating with Daconil, try the following cultural controls:
When watering, wet the entire root zone. Apply water once each week. Overwatering can stress the tree. Provide good drainage and avoid soil compaction. Avoid reflected heat by not planting close to buildings or paved surfaces. Don't use rock or black plastic as mulches (which can reflect heat and damage the tender leaves). Finally, don't overfertilize. If you recognize any of the above elements that may be causing stress to your red maple, correct them and the leaves should stop turning brown at the margins.
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