Crown Gall
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.
Tools, hands and cuttings
It travels on secateurs, stakes, gloves and propagation material. Work through healthy plants first and disinfect tools between plants.
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 20°C and 30°C, with humidity above 60%.
The signs that lead here
Full problem lists for these crops
About
Crown gall (Agrobacterium tumefaciens) is a soil-borne bacterium that induces tumour-like galls on roots and stems of roses, fruit trees, grapes and many woody plants, entering through wounds.
Symptoms
Rounded, rough, woody galls at the soil line, on roots, or on stems, starting soft and cream-coloured then hardening and darkening; reduced vigour and stunting.
Organic Treatment
Remove and destroy severely affected plants; on minor galls, excise and treat wounds. Dip new roots in a Agrobacterium radiobacter K84 biocontrol before planting.
Chemical Treatment
No curative chemical; the K84 biological preventive is the standard protection for susceptible nursery stock.
Prevention
Buy clean nursery stock, avoid wounding roots and stems, treat susceptible plants with K84 at planting, and don't replant galled sites.
Crops at risk
Related problems
Crown Gall 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.