cherry leaf spot

Symptoms

Small (1-3mm) purple-brown spots on upper leaf surfaces, spots fall out leaving shothole appearance, yellowing + premature drop of heavily-spotted leaves from June onward, defoliated trees by August in epidemic years, occasional fruit lesions and stem infections.

Plants affected

• sweet cherry
• sour cherry

Easily confused with

• cherry powdery mildew

  How to tell them apart: Blumeriella jaapii (cherry leaf spot) shows tiny, distinct purple to reddish-brown spots scattered across the UPPER leaf surface; the spots are firm, flat and well-defined, and their centres often dry out and drop away to leave clean 'shot holes'. On the underside, look for whitish to pinkish spore masses sitting inside those same spots in damp weather. Heavy infection turns whole leaves yellow and causes early leaf drop, often from the lower canopy upward. Podosphaera clandestina (cherry powdery mildew) instead forms a raised, white, felty, powdery COATING that wipes off with a finger, mostly on young leaves and shoot tips; affected leaves curl, blister and become distorted rather than spotted, and you never see clean holes punched through them.

• Japanese beetle

  How to tell them apart: On sweet cherry, Popillia japonica (Japanese beetle) chews the green tissue BETWEEN the veins, leaving a lace-like, skeletonized leaf with the fine vein network intact; damage is irregular and ragged, concentrated on sun-exposed upper foliage. Look for the insect itself: shiny metallic-green beetles with coppery wing covers, often feeding in clusters. Blumeriella jaapii (cherry leaf spot) makes small (1-3 mm) round purple-to-brown spots that later dry and drop out, leaving clean, circular 'shot-holes' with smooth edges; leaves turn yellow and fall heavily in mid-summer, and tiny white spore masses appear on the underside in damp weather. No insects and no skeletonization are present with the fungus. Popillia japonica is an EU-quarantine pest under Regulation (EU) 2019/2072 — if you find the beetles or this skeletonizing damage, report it to your national plant protection organisation (NPPO) immediately.

Common questions

How do I recognise cherry leaf spot on sweet cherry?

Small (1-3mm) purple-brown spots on upper leaf surfaces, spots fall out leaving shothole appearance, yellowing + premature drop of heavily-spotted leaves from June onward, defoliated trees by August in epidemic years, occasional fruit lesions and stem infections.

Do I have to report cherry leaf spot?

No. cherry leaf spot is not a notifiable organism, so there is nothing to report to an authority. Treat it as a normal garden problem.

How is cherry leaf spot treated?

Mainly with biological and cultural measures — removing affected material, changing the conditions that favour it, and treating with agents approved in your country. The exact steps and their timing depend on the plant, the season and where you live: Dr. Phyto works them out in a free diagnosis.