Blackleg on broccoli leafDark lesions on stems of cabbage-family plants are an early symptom of this fungal disease. Lesions may also appear on roots at or just below the soil surface. Cabbage, broccoli, turnip and Brussels sprouts are the most susceptible crops. Infected plants usually wilt and die. Symptoms may appear at any time in the plant?s growth cycle.

The fungal spores are spread by rain, wind, and human activity. Black leg is most common in cool, moist conditions. The fungus overwinters in seed and plant debris.

Prevention and Control

  • Plant disease-free seeds and plants.
  • Set up a four-year rotation of cabbage-family plants in your garden if space allows.
  • Space plants widely to promote drying of foliage.
  • Avoid touching plants when they are wet.
  • Mow or remove cabbage-family weeds growing in or near your garden.
  • Remove diseased plants. Compost infected plant material only if compost temperature reaches at least 150 degrees F. for several days.

Last updated: 03/18/2024