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Quick guide to insects and diseases of tomatoes

Quick facts

  • This page highlights non-chemical practices to prevent or manage common insect and disease problems of tomatoes. 
  • 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.

Leaf spot and fruit rot diseases

Septoria leaf spot
  • Plant tomatoes where no tomatoes, potatoes, peppers or eggplants have been for the past 3-4 years.
  • Keep tomato leaves as dry as possible.
    • Water with drip irrigation or a soaker hose.
    • Water in the morning so leaves dry quickly in the sun.
    • Stake or cage plants.
    • Space plants so that air flows between them.
  • Mulch all exposed soil with plastic or organic mulch.
  • Scout tomato plants once a week.
    • Look at lower leaves for leaf spots.
    • Remove infected leaves and rotten fruit from the garden.
  • Remove or bury tomato plants at the end of the season.

More information on early blight of tomato.

More information on bacterial spot of tomato.

Blossom end rot

  • Irrigate to keep soil moisture even.
  • Mulch the soil to maintain soil moisture.
  • Don't use too much fertilizer, especially nitrogen.
  • Avoid damaging roots. Don't dig or cultivate for weeds close to the plant.

More information on blossom end rot.

Viral diseases

  • Remove and destroy infected plants.
  • Remove weeds in the field.
  • Clean tools and hands after touching infected plants.

More information on tomato viruses.

Cutworms

  • 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.
  • Cover plants with a row cover (light weight fabric — remove when tomatoes are flowering).
  • Plant a trap crop, like radish, before tomatoes.

More information on flea beetles.

Reviewed in 2019

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