Marianne's Response
Yellow and blackening of Rose of Sharon
This has been going on for years, one rose of sharon bush in particular, especially when stressed, e.g. heat, (well watered but not drowning) starts to get all the leave spotted, holes develop, black spots, yellowing. It is usually solved by removing, slowly, all the leaves, allowing all new fresh green leaves to come out and it stays nice, sometimes for the rest of the season. Suggestions, analysis?
Posted by theodore jaffe on August 28, 2019
Marianne's Response
Sounds like a classic response to stress - leaf blight is a fungus that overwinters in the soil and moves in when a plant has a low defense due to stress and moisture on the foliage. Try watering with a soaker hose so foliage stays dry and clean up all fallen foliage in the fall. Then use a wood chip mulch all around the base of the shrub to both seal in moisture and block any of the disease spores from splashing up onto the plant during watering or rain storms. I think your Rose of Sharon will be much happier next summer with a mulch around the roots. Keep growing, Marianne Binetti
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