Bacterial Leaf Spot
Risk near you, next 48h
See whether your local forecast favours this disease right now.
When it strikes
Treat, then re-check in 5–7 days
Pick off the worst material, apply the organic option below, and look again after five to seven days. If the spread continued, escalate rather than repeating the same treatment.
Rain and irrigation splash
Water splashing off soil and infected leaves carries it upward and along the row. Watering at the base and mulching the soil surface break the route.
It carries over to next season in soil, debris or seed — which is why rotation matters here, not just treatment.
Keep out of the compost
This survives a garden heap. Bag it for municipal green waste, which is composted industrially at temperatures a garden heap cannot reach, or burn it where that is permitted.
When and where to look
Scout the planting while temperatures hold between 22°C and 32°C, with humidity above 80%, after rain or heavy dew, while the leaves are still wet. Risk builds after roughly 6 unbroken hours of those conditions, so the morning after such a night is the moment to look.
The signs that lead here
Full problem lists for these crops
About
Bacterial leaf spot (Xanthomonas and Pseudomonas) affects peppers, tomatoes, stone fruit and leafy greens in warm, wet, splashy weather, spreading fast through rain and overhead irrigation.
Symptoms
Small, dark, water-soaked angular spots often with yellow halos that may drop out to leave a shot-hole; scabby raised lesions on fruit; defoliation in severe cases.
Organic Treatment
Remove infected leaves, avoid working among wet plants, mulch to stop splash, and apply copper preventively. Use clean, hot-water-treated seed.
Chemical Treatment
Copper combined with mancozeb; rotate to limit copper-resistant strains.
Prevention
Start with certified disease-free seed and transplants, rotate crops, water at the base, and avoid handling wet foliage.
Crops at risk
Related problems
Bacterial Leaf Spot risk by location
Each location has a month-by-month profile computed from the weather archive: how many hours a year actually meet this disease’s thresholds.