Cherry leaf spot: how to recognise and treat it

Disease

Cherry leaf spot — Photo: Glen R. Stanosz, University of Wisconsin-Madison; Mary L. Torsello, USDA Forest Service, Public domain, Wikimedia Commons

Symptoms

Small reddish to purple round spots on the upper side of the leaves.
White to pink spore masses on the underside of the spots in wet weather.
Spotted leaves turn yellow and drop early; a badly hit tree can lose all its leaves.
Dead tissue may fall out of the spots, giving the leaves a tattered look.

Organic treatment

Pick off diseased leaves as soon as they appear and dispose of them away from the tree.
Sulfur sprays covering all the leaves reduce the disease after a bad year.

Chemical treatment

Fungicide with captan or myclobutanil from petal fall into mid-summer, alternating them; follow the label dose and pre-harvest interval.

Reference information, not a guarantee. Read and follow the label of any product: dose, safety and the days to wait before harvest.

Prevention

Rake up and remove fallen leaves in autumn, where the fungus overwinters.
Spreading nitrogen on fallen leaves in autumn helps them decompose faster.
Start protective sprays at petal fall in the season after an outbreak.

Plants it affects

Sources

Figures checked against these sources.