By Bobkfler
United States 
On one of my photinia plants, the leaves have large reddish brown patches, sometimes covering most of the leaf. I only water them once a week. What could these patches be?
27 Jun, 2012
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« What could the brown spots on my honeysuckle and clematis leaves be?
Entomosporium leaf spot is , I believe, the technical term for the spots on your leaves. Remove them and any that fall and spray the plant with a fungicide spray. Bushes or hedges that are subject to this leaf spot are best sprayed when the leaves are young as a preventative measure and repeated every 10 days or so. The mature leaves then should then be OK.
These shrubs like an open position with good air circulation. Position is often the source of the problem rather than water or lack of water.
27 Jun, 2012