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How To Stop Tomato Hornworms From Damaging Your Vegetable Plants

As summer arrives and your garden plants begins to grow, it’s time to start thinking about tomato hornworms, and more importantly, stopping them before they cause serious damage to your crops.

Tomato and tobacco hornworms are notorious for devouring foliage, stems and even the fruit of tomato plants. But they also attack and destroy pepper, eggplant, and even potato plants as well.

Unfortunately, if left unchecked, they can seriously impact a garden’s health and production levels. Knowing how to stop them all begins with understanding their life cycle, and knowing how and when they attack.

The Tomato & Tobacco Hornworm

There are actually two types of common hornworms, the tobacco hornworm, and the tomato hornworm, and unfortunately, both varieties need to be stopped.

Tobacco hornworms have a small red spike protruding from the top of their body, and 7 white stripes. Tomato hornworms, on the other hand, have a brown spike on top and 8 stripes.

The moth stage of tomato and tobacco hornworms. The moths can hover and fly much like a hummingbirds does.

Hornworms begin their life cycle as a moth emerging from a pupa state in the ground in early spring. The moths are magnificently large creatures, and are incredibly adept at flying.

Once they emerge, they feed on the nectar of flowering plants. As they do, time, they also deposit tiny eggs on the foliage of young, tender vegetable plants. Once laid, the eggs hatch within days into the catepillar (hornworm) stage.

Not only does the cycle occur in the spring, but it can also happen a few more times suring the summer too! And unless stopped, the hornworm damage begins!

How To Stop Tomato Hornworms In The Garden

The best line of defense for controlling tomato hornworms and their damage is early detection.

larva in ground
Tomato hornworms bury in the ground to become a moth in their adult stage. They can have two to three life cycles during the summer.

The moths, with their lightening fast flying habits, are nearly impossible to catch. That leaves finding them early on plants as the best line of defense for stopping tomato hornworms. And that can certainly be tricky!

Although both species adult hornworms can reach lengths of up to four inches, they can still be hard to spot. Their body is perfectly camouflaged to blend in with the green foliage, and they seem to become one with the plants.

But there are a few secrets to making finding and removing hornworms a bit easier.

The Keys To Spotting and Stopping Tomato Hornworms

stopping tomato hornworms
Hornworms can be hard to spot with their translucent green bodies.

Daily patrols of your garden to look for damage and signs is the real key to stopping tomato hornworms. A hornworm can and will devour large portions of a plant in a single day.

As you walk, look for the two most common signs that a hornworm is present – plant damage, and the presence of green manure.

Hornworms will chew and strip the limbs and foliage. If you spot the nubs of a branch, there is likely a hornworm nearby. An even better way to find and stop tomato hornworms earlier is to look for their manure on the leaves of plants. Small, green lumps indicate fresh manure, and the nearby presence of a tomato hornworm.

tomato hornworm damage
Stripped leaves and stems are the tell-tale signs a hornworm is near.

If you spot the manure, scan the nearby branches and leaves, and you are sure to find a tomato hornworm lurking.

The Black Light Method To Find & Stop Tomato Hornworms

Another great method for finding hornworms involves the simple use of a black light at night. The translucent body of the hornworm glows bright green under a black light.

black light
A simple black light flashlight can make spotting and stopping hornworms a breeze.

Simply take a nighttime stroll through your garden using an inexpensive black light flashlight. As you shine the light on your plants, the hornworms light up, making them easy to spot and remove. (Product Link : Letion UV LED Blacklight)

It can certainly be a far easier method for stopping tomato hornworms than trying to find their camouflaged bodies during the day!

Wasps And Hornworms

There is a bit of natural help in stopping hornworms as well, and it comes from the paper wasps that frequent the garden.

This hornworm has been used as a host by the paper wasp to lay it’s eggs. Wasps are a big help in controlling hornworm damage.

Braconid, or common paper wasps actually deposit their eggs on the back of hornworms, and it eventually destroys the hornworm as they hatch. If you spot a hornworm with white eggs on its back, it is a sure sign you are getting a little help from your wasp friends!

Here is to stopping tomato hornworms from damaging your vegetable plants – for more information on controlling pests in the garden, check out our Garden Pests section on the blog.

This Is My Garden is a website dedicated to spreading the love and knowledge of gardening around the world. We publish two new garden articles each week. This article may contain affiliate links.