Raspberry Cane Blight
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 12°C and 26°C, with humidity above 85%, after rain or heavy dew, while the leaves are still wet. Risk builds after roughly 8 unbroken hours of those conditions, so the morning after such a night is the moment to look.
Rule these out first
Same category, and at least one host crop in common — so they are genuinely confusable in the same part of the garden.
The signs that lead here
Full problem lists for these crops
About
Cane blight (Leptosphaeria coniothyrium) enters raspberry canes through wounds — cane midge damage, careless tying, hoe cuts — and then kills the cane from that point upwards. It is the usual explanation when a healthy-looking row suddenly dies back the summer after planting.
Symptoms
Leaves on one cane wilt and die while neighbouring canes look fine. The base of the cane turns dark brown and brittle, and the bark cracks and peels away to show grey fungal growth beneath. Affected canes snap off cleanly at the base.
Organic Treatment
Cut affected canes right out below soil level and burn or bag them. Disinfect secateurs between cuts. Avoid hoeing near the crowns and tie canes loosely with soft twine so the bark is never chafed.
Chemical Treatment
No effective garden fungicide. Controlling raspberry cane midge — whose larval tunnels are the main entry wound — with an approved insecticide at bud burst indirectly reduces blight.
Prevention
Plant certified virus-free canes into free-draining soil, never into an old raspberry bed. Keep the row narrow, avoid any mechanical damage to cane bases, and remove spent canes cleanly at ground level every year.
Crops at risk
Related problems
Raspberry Cane Blight 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.