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Quick guide to insects and diseases of broccoli, cabbage and cauliflower

Quick facts

  • This page highlights non-chemical practices to prevent or manage common insect and disease problems of broccoli, cabbage and cauliflower. 
  • These insects and diseases are common on many plants in the cabbage family, including kale, radish, turnip, rutabaga, Brussels sprouts, arugula, collards and mustard greens.
  • For more detailed information follow the links in each section.
  • Click on an image to enlarge it.
  • See Growing healthy vegetables for more detailed information on how to keep your garden disease and pest free.

Black rot and gray leaf spot

  • Do not save seed from infected plants.
  • Purchase high-quality seed. Some companies certify seed to be disease-free.
  • Use drip irrigation.
  • Space plants for good air movement and drying.
  • Do not work in plants when wet.
  • Control weeds in and around crops.
  • Remove and destroy or bury infected plants after harvest.
  • Do not plant members of the cabbage family in the same location for 3-4 years.

Cabbage maggots

  • Do not use animal or green manure in spring.
  • Delay planting cabbage family vegetables (until after June 1).
  • Remove and destroy host plants in the fall.
  • Cover plants with a row cover (lightweight fabric) in spring.
  • When using row covers, do not plant vegetables in the cabbage family in the same area two years in a row.

More information on cabbage maggots.


Green stems sliced off at their base
  • Remove weeds and plant residue.
  • Till garden before planting.
  • Place cardboard collars or aluminum foil around plant stems when planting transplants.

More information on cutworms.

Flea beetles

  • Plant as late as possible.
  • Control weeds and remove old plants.
  • Cover plants with a row cover (lightweight fabric) until harvest.

More information on flea beetles.

Cabbage loopers and cabbage worms

  • Destroy old plants after harvest.
  • Handpick caterpillars and place them in a container of soapy water.
  • Cover plants with a row cover (lightweight fabric) until harvest.

More information on cabbage loopers and cabbageworms.

Authors: Michelle Grabowski and Jeffrey Hahn, former Extension educators

Reviewed in 2021

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