Brown spots on hydrangea leaves: causes and fixes

The most common causes of brown spots on hydrangea leaves are sun scorch (brown edges, worst in hot afternoons), Cercospora leaf spot (tan-brown circles with purple halos), and bacterial leaf spot (angular, water-soaked spots that turn brown). All are typically cosmetic — they lo

By Thomas Joseph Published 2026-06-11 Updated 2026-06-13 Reviewed by Thomas Joseph 7 min read

Hydrangea leaves develop brown spots for several different reasons, and the appearance of the spots — their size, shape, position on the leaf, and the presence or absence of halos — are the diagnostic clues that point toward the right response.

Quick diagnostic table

Brown spot pattern	Location	Additional clues	Most likely cause
Brown leaf edges/margins	Lower and outer leaves	Worse in heat; crinkled edges	Sun scorch or salt damage
Circular tan-brown spots, purple halos	Any leaf, lower first	Small-medium circles; may coalesce	Cercospora leaf spot
Angular, water-soaked then brown	Any leaf	Bounded by veins; irregular	Bacterial leaf spot
Large irregular brown patches	Top of plant	Sudden appearance after dry period	Drought stress
Brown spotting on flowers	Flowers only	White/gray mold on wet flowers	Botrytis blight
Tan to brown papery spots, no halo	Any location	Spots dry out and fall out	Anthracnose

Reader questions

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Are brown spots on hydrangea leaves dangerous to the plant?

Per NC State Extension, "leaf spot diseases of hydrangea are cosmetic in most cases and do not threaten the long-term health of established plants." Heavy defoliation from Cercospora leaf spot weakens the plant somewhat, but the root system and crown remain viable and the plant re-foliates normally the following season.

How do I tell Cercospora from anthracnose on hydrangea?

Cercospora spots are circular with a distinctive purple-red halo around a tan center. Anthracnose spots tend to be more irregular, larger, and may cause the spot centers to dry out and fall out, creating a "shot-hole" appearance. Per NC State Extension, "laboratory confirmation is necessary for a definitive diagnosis of hydrangea leaf spot diseases."

Why does my white-flowered hydrangea have brown flowers, not brown leaves?

Brown flower discoloration is usually botrytis blight or age-related browning rather than leaf spot diseases. All hydrangea flowers brown as they age — this is natural. Botrytis causes faster browning combined with gray mold, occurring in cool, wet weather.

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Brown spots on hydrangea leaves: causes and fixes

Quick diagnostic table

Brown spots on hydrangea leaves: causes and fixes

Quick diagnostic table

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