If you’re wondering how to get rid of tomato hornworms naturally from your home garden, this post is for you! Here are six different organic methods and best practices for eliminating these destructive pests, plus natural prevention tips and tricks to break the tomato hornworm life cycle to try to keep them from returning next year.

Understanding Natural Tomato Hornworm Control in Your Vegetable Garden

Tomato hornworms are nasty looking HUGE green worms. They are some of the largest caterpillars in North America, getting up to 4 inches long with their vicious appearance!

Don’t worry though – these large green caterpillars aren’t likely to bite or sting you, but they will cause significant damage to your tomato plants and other nightshade plants when they invade your organic garden with their voracious appetite.

Welcome to the HOW TO KILL GARDEN PESTS SERIES! 

Who knew gardeners could take such pleasure in murdering annoying garden pests. If you garden, you’ll want to check out on the posts in this HOW TO KILL series. I’m adding new posts to this series each week, so subscribe to my newsletter if you want to know when they’re ready!

• How to Kill Cucumber Beetles
• How to Kill Potato Beetles
• Murdering Japanese Beetles
• How to Kill Cabbage Worms
• How to Kill Tomato Hornworms
• Controlling and Preventing Squash Bugs
• How to Get Rid of Squash Vine Borers

Identifying Tomato and Tobacco Hornworms in Your Garden

There are actually two hornworms that attack tomatoes: 

1. Tomato hornworm, Manduca quinquemaculata
2. Tobacco hornworm, Manduca sexta

They look pretty similar. They’re both huge, nasty beasts that cause extensive damage to members of the nightshade family: tomatoes, potatoes, eggplants, and peppers. The easiest way to tell them apart is by their horn.

What are Tomato Hornworms?

Tomato hornworms have a black horn and v-shaped white markings on their abdomen. These tomato worms are supposed to be more common in the Northern United States and Southern Canada, and require effective natural control. Their large size and green color help them blend perfectly with tomato leaves.

What are Tobacco Hornworms?

Tobacco hornworms have a red horn and white stripes – diagonal lines – on their abdomens. That means, most of the hornworms I have in my garden are actually tobacco hornworms and not tomato hornworms, even though tobacco hornworms are supposed to be more common in southern states.

Honestly, it doesn’t much matter which type you have. If you find these large caterpillars, you need to get rid of tomato hornworms naturally before they completely defoliate your plants. Both types are terrible garden pests that can destroy an entire tomato plant overnight.

The Destructive Life Cycle of Garden Hornworms

The adult forms of hornworms are known as sphinx moths or hawk moths, types of hummingbird moths. These large moths are actually beneficial pollinators in their adult form, but their larvae stage is devastating to gardens.

These adult moths emerge toward the end of the season in late spring where they mate and lay eggs at night on plant leaves over the next 20 to 30 days. A female moth can lay up to 2000 hornworm eggs!

The eggs will hatch in less than a week, becoming tiny caterpillars that begin eating tomato leaves. If tomato leaves are not available or they have been consumed, the hornworm larvae will eat related veggies for up to one month until they reach full size.

The hornworm will then pupate after burrowing into the garden soil for another week where it will emerge as a sphinx moth ready to mate and lay more eggs. Multiple generations per season are common, especially in optimal conditions during early summer.

Hornworm pupae are big, brown, and look a bit like a cigar. I find some every year in my garden and I am quick to feed them to the chickens!

What Damage Do Tomato & Tobacco Hornworms Cause?

The dreaded tomato hornworm causes complete and utter destruction. It will strip missing leaves overnight off any nightshade plant. An infestation can defoliate entire plant rows killing the tomato crop, making preventative measures essential for your home garden.

Natural Methods to Get Rid of Tomato Hornworms

Companion Plants to Help with Hornworms

Companion planting is always good to have in the vegetable garden to help deter harmful pests and attract good ones.

Dill plants, basil and marigolds are excellent companion plants for hornworm deterrent to help hide tomato plants from eggs being laid. That said, I have these plant species around my tomato plants every year and I still get hornworms.

Using Trap Crops for Hornworms

Tomato hornworms see everything as their favorite food. If you want to try trap crops, you could plant a tomato you have no interest in along the edges of the garden in the hopes that the moths will lay eggs on the trap crop. Honestly, as in life, there’s no guarantee that will actually happen.

Organic Solutions for Tomato Hornworm Control

Hand Picking Hornworms

Hand picking the hornworms and dropping them into a bucket of soapy water is the fastest natural treatment and often the most effective way to address a tomato hornworm problem. If you see any hornworm eggs – squash them with or without gloves on, or remove the leaves you see the eggs hatching on.

Personally, I don’t like to touch hornworms, so I break/cut the leaf off and drop it into a pail of soapy water or save them for my chickens.

Hornworms hide very well among the leaves so it is always easier to spray the leaves with a foliar spray or water first. They’ll start to move around making it easier to find and hand pick them.

The best time for a hornworm hunt is in the early morning when they’re more active and visible on your tomato plants. Handpicking these large green caterpillars is my best solution for getting rid of these pests naturally. I take sick delight in watching my chickens fight over them!

Using UV Lights to Find Hornworms

A lot of people have mentioned using UV flashlights to find hornworms at night – apparently they glow! I’ve never tried this because UV lights used to be quite expensive. 

Now that they’re affordable I might give it a shot! But honestly, with slow diligence, it’s not hard to find tomato hornworm caterpillars during the day.

Hornworm Poop

One way to more easily find hornworms is to look for their black droppings. This green / black pellet poop is quite large and obvious. When you see it, you know there’s a tomato hornworm nearby on your plant leaves.

bT Spray for Hornworms

Spraying the leaves and soil with Bacillus thuringiensis (Bt) Spray as soon as you notice the young caterpillars is also a good bet at beating them.

Use Bt and spray the leaves and soil to help kill the hornworms off. Bacillus thuringiensis is a bacteria that infects and kills caterpillars like cabbage worms. It’s approved for organic gardening and provides an effective natural control of hornworms without resorting to chemical insecticides.

Bt spray is quick to handle caterpillar issues as the bacteria keeps on going. An added benefit is it is nontoxic to mammals and bees. However, Bt WILL kill ALL caterpillars (including Monarchs) so be careful when spraying it. If you have the space you can support monarchs by creating a safe space for them far away from any overspray.

Following packaging directions, I mix a small amount into a spray bottle and spray it on leaves. You can also syringe some up and stick it directly into any spots that show where one has bored into your garden plants.

Soapy Water Spray

You can also mix up your own insecticidal soap spray as an organic solution. Add a bit of cayenne pepper to really make those caterpillars die. This natural pesticide is effective against small caterpillars and should only be used as a last resort.

Using Diatomaceous Earth to Kill Hornworms

 If you want to use diatomaceous earth to kill pests, you’ll need the food grade version. Food Grade Diatomaceous Earth is helpful for a lot of pests. It’s nontoxic and works best in dry conditions.

To use DE to naturally control hornworms, sprinkle the DE around the plant – keep it out of blooms if possible. When the hornwoms walk through it, it will enter their body at the rear end and start to dry them out.

DE has pros and cons. The pros are it’s effective at killing bugs. The cons are – it can harm bees. Another con is that you really need to wear a dust mask when applying it to keep your lungs safe.

Eco-Friendly Ways to Break the Tomato Hornworm Lifecycle

Not only is knowing how to get rid of tomato hornworms naturally important, but figuring out how to break the lifecycle so you can prevent tomato hornworm infestations in the future is also helpful. Here are a few things you can try to break the hornworm life cycle so they leave your vegetable garden alone.

Beneficial Nematodes 

Drench the garden soil with beneficial nematodes to kill the pupating larvae during summer or the overwintering pupa. As it enters the soil will attack and kill them to prevent them from coming back out. I have been using beneficial nematodes in my garden for a couple years now and am seeing good results with them as a natural pest control method.

Crop Rotation

A good garden practice is to use crop rotation to help keep pests at bay. A good recommendation is that you should only plant the same crops in the same area once every three years.

That said, I don’t usually follow this guidance because I let volunteers grow. Feeding with good compost helps replenish nutrients when crops are regrown in an area.

However, crop rotation helps disrupt pest life cycle by interrupting their food supply. A good rotation for tomatoes is to plant nitrogen fixing beans there the next year.

Row Covers

Using row covers in early summer can prevent adult moths from laying eggs on your tomato plants in the first place. This preventative measure can be one of the best ways to avoid a tomato hornworm problem altogether.

Tilling the Soil

If you had a huge infestation last year, you can try tilling the soil.  It has been shown to kill the overwintering pupae. I don’t really like to till my soil so I haven’t tried this myself.

Sustainable Practices to Control Hornworms in the Future

Attract natural predators and helpful beneficial insects to help control hornworms in your vegetable garden. Predatory insects include:

• Parasitic wasps (braconid wasps and paper wasps)
• Lady beetles
• Green lacewings

Plant a beneficial nursery of flowers and herbs that beneficial insects like to help attract them to your garden. These predatory insects are often the only thing needed for natural control in a balanced garden ecosystem.

Parasitic Wasps 

Parasitic wasps are a powerful biological control method for naturally eliminating hornworms. Braconid wasps lay wasp eggs under the skin of the hornworms where the wasp larvae consume the hornworm from the inside out.

Parasitic wasps are crazy to watch – I almost feel sorry for hornworms when I see them infected with those little white cocoons. Almost. LOL

Remember never kill the hornworm with white cocoons on it! You want these parasitic wasps to hatch and lay more eggs on more hornworms.

Other Natural Solutions

Neem oil can be used as an organic pesticide on your tomato plants to deter adult moths from laying eggs. Apply it in the evening to avoid harming beneficial pollinators during the day.

And that’s what I know about how to get rid of tomato hornworms naturally! Using these organic methods and natural prevention techniques will help you protect your tomato plants while maintaining an eco-friendly garden. Gardening means we’re always learning and trying new things! Including learning how to effectively deal with garden pests using natural solutions.

Have you had Tomato Hornworms in your vegetable garden? What was get rid of tomato hornworms naturally?