How to Get Rid of Hornworms on Tomato Plants

Hornworms are easy to spot because of their size.

Tomato hornworms are large worms that consume the foliage of tomato plants, along with eggplants and potatoes. The adult moths lay eggs on both sides of tomato leaves during the spring. Once the eggs hatch, the larvae consume the plant and then burrow into the soil. The most effective method of getting rid of hornworms is to pick them off your plants by hand and drown them in soapy water, according to the University of Minnesota.

Things You'll Need

• Bucket
• Warm water
• 1/4 cup liquid dish soap
• Insecticidal soap
• Garden tiller

Instructions

1. Pick off any hornworm eggs you find on your tomato plants in the late spring. The eggs are oval and are yellow or light green.

2. Pick off any hornworm larvae you find on the tomato plants. Begin checking the plants for larvae one week after you find eggs. Any eggs you miss will hatch around that time.

3. Fill a bucket with warm water and add 1/4 cup liquid dish soap. When you pick off the hornworms, drop them in the bucket to drown. Do not pick off hornworms that appear to have white horns coming out of their backs. These hornworms are hosting beneficial parasitic wasps that will hatch and kill any other hornworms present.

4. Spray the tomato plants with an insecticidal soap, covering the entire plant, according to the package directions. The soap will kill any hornworms you may have missed. Repeat the application until you stop seeing hornworm activity.

5. Use a garden tiller to till the soil to a depth of 12 inches immediately after your last harvest of the summer. The tilling will kill most of the hornworms that burrowed into the soil.

References

• University of Minnesota: Tomato Hornworms in Home Garden
• University of Minnesota VegeEdge: Tomato Hornworm