Clubroot is a fungal disease that causes finger-like swellings on the roots of the members of the Cabbage family – hence the alternative name, ‘finger-and-toe’. It occurs frequently on wet, acid soils but very seldom on limy soils. Affected plants are stunted and fail to develop. Spores can survive in the soil for many years.
Improving drainage, and applying lime to raise the pH to over pH7 are two ways to reduce the disease.