Club root affects vegetables and flowers in the cabbage family. Plants infected by the fungus wilt during the heat of the day, and older leaves yellow and drop. Roots are distorted and swollen. Avoid club root by choosing resistant cultivars and raising your own seedlings. The fungus has spores that can persist in soil for many years. If you’ve had past club root problems, adjust the soil pH to at least 6.8 before planting susceptible crops.