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Rose Bushes Summer Yellowing: Black Spot on Grafted Roses

Philadelphia roses: leaves yellow and drop late July-August, return by September. Annual cycle.

Cause

Black spot on grafted hybrid roses. Old/antique roses on own roots shed infected leaves and regrow clean—less care. Neem oil works on antiques; unsure on grafted hybrids. Grafted roses need specific sprays (often toxic).

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