How Do Hornworms Get on Tomato Plants?

Tomato plants are a favorite food source of hornworms, which are large, green, caterpillar-like insects that can devour entire leaves and fruits within a matter of days. If left unchecked, hornworms can quickly decimate a tomato plant, making it important for gardeners to be aware of how these pests get on tomato plants in the first place.

Hornworm Life Cycle

Before understanding how hornworms get on tomato plants, it's important to understand their life cycle. Hornworms start as eggs laid on tomato plant leaves. These eggs hatch into tiny caterpillars, which grow quickly over the course of 3-4 weeks, up to 4 inches in length. Once they reach maturity, they burrow into the soil to pupate before emerging as a moth.

How Do Hornworms Get on Tomato Plants?

There are a few ways that hornworms can get on tomato plants:

From adult moths: Adult moths lay eggs on tomato plant leaves, which hatch into caterpillars that eventually become hornworms.

From neighboring gardens: If a neighboring garden has hornworms, they can easily travel to your garden through natural migration or on light breezes.

Through contaminated soil or mulch: Hornworm eggs can also hitch a ride in soil or mulch that's brought into your garden, even if it comes from a seemingly insect-free source.

No matter how hornworms get on your tomato plants, it's important to take action quickly to prevent widespread damage.

How to Prevent Hornworms on Tomato Plants

Preventing hornworms on your tomato plants is the best course of action. Here are some tips to keep hornworms away:

Use floating row covers: These lightweight covers can be placed over tomato plants to prevent adult moths from laying their eggs. Be sure to remove the covers once the plants start to flower, so that the bees can pollinate them.

Bring in beneficial insects: Certain insects like braconid wasps can be introduced to your garden to help control hornworm populations.

Handpick hornworms: If you notice hornworms on your tomato plants, you can pick them off by hand and destroy them.

Rotate crops: Hornworm eggs can remain in the soil during the winter, so it's important to rotate crops to prevent re-infestations.

If you do notice a hornworm infestation on your tomato plants, it's important to act quickly to prevent widespread damage. With the right strategies, you can keep your tomato plants healthy and productive throughout the growing season.