Clubroot
Disease A soil-borne disease of brassicas that causes swollen, distorted roots.
What to look for
Stunted plants with leaves that wilt on hot days, often with a purple tinge. The roots are swollen and knobbly. Spores can live in the soil for up to 20 years.
When: Spring to autumn, worst in wet, acid soil.
How to prevent it
- Test the soil and lime it to a pH of 7 or above before planting brassicas.
- Buy plants from trusted sources, or raise your own in pots.
- Plant brassicas as larger pot-raised plants.
- Choose clubroot-resistant varieties.
- Clean boots, tools and pots to avoid spreading soil from infected beds.
How to deal with it
- There is no cure, so lift and bin affected plants and do not compost them.
- If you have clubroot, grow non-brassica crops in that soil or use resistant varieties and raised beds with clean soil.
- Remember that radish, swede, turnip, mooli and wallflowers also host it.
Crops it affects
If you choose to use any treatment, use only products approved for UK home gardens, follow the label and avoid spraying open flowers. See all pests and diseases.