Club Root UK

Club root (Plasmodiophora brassicae) is a soil-borne disease that deforms brassica roots and persists in soil for 20+ years. There is no cure — prevention is everything.

Disease information verified against RHS guidance by the SoilCommander Growing Team.

Symptoms

• Plants wilt during the day even when soil is moist, then partially recover at night
• Stunted, yellow-green leaves
• Lifting infected plants reveals swollen, distorted ‘club-like’ roots
• In severe cases plants collapse and die before cropping

How It Spreads

Club root spores survive in soil for 20–25 years and are spread by: water movement; contaminated tools or boots; bringing in infected soil or transplants. One infected plant can release billions of spores into the soil.

Prevention

• Raise soil pH to 7.0+: club root thrives in acidic soil; lime the bed in autumn and retest before sowing. Raising pH doesn’t eliminate the disease but significantly reduces its severity
• Rotate brassicas: never grow brassicas in the same ground for more than one year in four
• Choose resistant varieties: Kilaton F1 (cabbage), Clapton F1 (cabbage), Caraflex F1, and Supervisor F1 (swede) have strong club root resistance
• Raise transplants in deep pots: starting brassicas in 9cm deep individual pots gives them a strong root system before planting out, helping them outgrow mild infection
• Don’t bring in soil: avoid using soil from other gardens or buying bare-root brassica transplants from unknown sources
• Clean tools: disinfect all tools that have been in contact with infected soil before using in other beds

See all disease guides: Garden Problems UK