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Tomato Hornworms: How to Identify, Control, and Prevent Them

Photo Credit
Amanda Hill

Spot Them Early and Save Your Tomatoes: Expert Tips for Gardeners

Written By: Catherine Boeckmann Executive Digital Editor and Master Gardener

Big, green, and hungry—tomato hornworms can wipe out your tomato crop almost overnight. These giant caterpillars love to feast on tomato leaves and fruit, and they won’t stop there. Peppers, eggplants, and potatoes are also on their menu.

”This one is nobody’s friend if you’re a gardener and like to grow tomatoes,” says entomologist Jeff Smith, curator of the Bohart Museum of Entomology’s Lepidoptera collection.

The good news is that these pests are easy to spot once you know what to look for, and they can be controlled without resorting to harsh chemicals. In this guide, learn how to identify tomato hornworms, understand their life cycle, and discover effective natural ways to get rid of them—plus tips to keep them from coming back next year.

🐛 Hornworms munching your tomatoes? Our Almanac Garden Club members get exclusive pest guides, expert webinars, and practical tips to protect their crops. Protect Your Garden Now.

What Are Tomato Hornworms?

If you’ve ever walked out to your tomato plants and found bare stems where lush foliage used to be, chances are hornworms were at work.

  • The tomato hornworm (Manduca quinquemaculata) and the closely related tobacco hornworm (Manduca sexta) are garden pests found throughout most of the U.S. and southern Canada.
  • Both species feed on plants in the nightshade family (Solanaceae): tomatoes, eggplants, peppers, tobacco, and potatoes.
  • Because of their size and appetite, a small number of hornworms can defoliate plants quickly.

These pests are the larval stage of large night-flying moths (sphinx or hawk moths).

Tomato Hornworm crawling on a tomato vine.
Tomato troublemaker in action—meet the tomato hornworm! Photo by Amanda Hill.

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Identification

How to Identify Tomato Hornworms

Look for big, green worms on tomato plants! Hornworms are some of the largest caterpillars in the garden. Key features include:

  • Color: Pale green with V-shaped white markings along the body
  • Horn: Dark, pointed “horn” protruding from the rear
  • Camouflage: Blends almost perfectly with tomato leaves, making them tricky to spot
  • Size: Can reach up to 4–5 inches in length

Tip: Inspect your tomato plants daily. Check the undersides of leaves for eggs and watch for early signs of feeding damage.

Tomato Hornworm vs. Tobacco Hornworm

Both species damage tomato plants, but here’s how to tell them apart:

  • Tomato hornworm: White V-shaped markings; black horn
  • Tobacco hornworm: Diagonal white stripes with black spots; red horn
tobacco hornworm
Can you tell which hornworm this is? 
(It’s a tobacco hornworm! Notice the white stripes with dotted black lines and a red “horn.”) 

Signs of Tomato Hornworm Damage

  • Chewed or missing leaves, often starting at the top of the plant
  • Wilted stems and bare stalks
  • Dark green droppings (frass) on leaves or soil
  • Chewed fruit and sunscald on tomatoes (caused by loss of leaf cover)

Tomato Hornworm Life Cycle

Understanding the life cycle helps you prevent infestations:

  1. Eggs: Laid on undersides of leaves in late spring; hatch within 1 week
  2. Larvae (hornworms): Feed heavily for 3–4 weeks
  3. Pupae: Burrow into soil to overwinter in a cocoon
  4. Adult moths: Five-spotted hawk moths emerge in spring to repeat the cycle

In warmer regions, there may be two generations per year.

Tomato hornworm moth (female)
Tomato hornworm moth (female). Look out for the moths in late spring. Photo by Didier Descouens/Wikimedia Commons.

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Control and Prevention

How to Get Rid of Tomato Hornworms

1. Handpicking

  • The most effective method for small gardens:
  • Check plants daily and remove caterpillars by hand
  • Drop them in soapy water, or feed them to backyard chickens

2. Use Organic Controls

  • Bacillus thuringiensis (Bt): A safe, natural bacterium that kills young caterpillars (must be ingested).
  • Neem oil or insecticidal soap: Can work on small caterpillars, but less effective on large hornworms

3. Encourage Natural Predators

  • Parasitic wasps lay eggs on hornworms (you may see white cocoons attached)
  • Ladybugs, green lacewings, and birds also feed on eggs and larvae

If you find a hornworm covered with white cocoons, leave it—the wasps will do the control work for you

A tobacco hornworm covered with parasitic wasp eggs.
Nature’s drama! A tobacco hornworm becomes a nursery for parasitic wasps.

How to Prevent Hornworm Infestations

  • Till soil in fall or spring to destroy overwintering pupae (up to 90% mortality)
  • Rotate crops—avoid planting tomatoes in the same spot year after year
  • Use companion planting: Interplant dill or basil to deter pests; plant marigolds at borders
  • Attract  beneficial insects  by planting nectar-rich flowers

Frequently Asked Questions

Do tomato hornworms bite?
No. They look intimidating, but they cannot sting or bite humans.

What does a tomato hornworm turn into?
A large five-spotted hawk moth, also called a sphinx or hummingbird moth.

When do tomato hornworms appear?
Eggs are laid in late spring, and larvae are most destructive from June through August.

Can tomato hornworms eat other plants?
Yes. They also feed on peppers, potatoes, eggplants, and tobacco.

More Help for Gardeners: See our Garden Pest and Disease Library for tips on other common problems.

Do you have tomato hornworms? How do you handle them in the garden?

Garden Pests
About The Author
Catherine Boeckmann

Catherine Boeckmann

Executive Digital Editor and Master Gardener

Catherine Boeckmann is the Executive Digital Editor of Almanac.com, the website companion of The Old Farmer's Almanac. She covers gardening, plants, pest control, soil composition, seasonal and moon c...
Read More from Catherine Boeckmann

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Comments

<a title="View user profile." href="/author/editors">The Editors</a> Fri, 09/13/2013 - 14:35
Thanks for sharing,Denisestl. We can imagine that hornworm munching away as hornworms do. What a great purpose for these otherwise "cute" green caterpillars.
<span>Susan R</span> Sat, 09/14/2013 - 02:51
My big geraniums were striped in just a few days. I didn't think geraniums had many enemies but when I looked closer they are covered with baby horn worms. I want to just cut them way back to try and control the infestation.
<span>Tabpoole</span> Mon, 09/09/2013 - 14:04
Growing tomatoes in a container" the plant box" first time in sev. Seasons for us. In louisiana using 'heat-resistant' tom. Var.good flavor!!! Thanks for great info on hornworm...we thought damage was being done by these little orange guys w/ black legs ~ 20 that hide in a group on cool side of one tomato, on the far side of container fr my two spectacular horn worms on other end.,will use light trick tonight to find more of these green rascals. Now to find out about the orange bugs...thanks FarmersAlmanac. My husband and i are from different generations of gardening., ya'll have restored peace in our garden and marriage.
<span>Lollerwaffle</span> Thu, 06/26/2014 - 21:47
The little black bugs with orange bodies and black legs that hang out in groups of 20 or so on the underside of the leaves are milkweed assassin bugs. They're kinda awesome. You're seeing them before they're fully grown. As adults they will assassinate garden pests and suck all the body fluids of their prey. Unless they're just milkweed bugs. If they remind you more of ants, like little soldiers, they're assassin bugs and safe to keep around.
<span>George Koertzen</span> Fri, 09/13/2013 - 16:05
I have a hanging Topsy Turvy and found three of these monsters have eaten everything. I was trying to figure out how they got there but apparently they hatched on my plant.
<span>Monica Cooper</span> Fri, 09/06/2013 - 14:43
I'm battling the horned worm as well but this morning found them on my milkweed plant! I've been waiting and waiting for the monarchs to lay eggs but instead an infestation of horned worms! I'll go out and get rid of them now that I've seen a pic of the monarch worms and know that's not what's on my plant! Gardening is such work and I'd like to eat my egg plants growing and not feed the worms!
<span>D. Marcus</span> Sat, 08/24/2013 - 22:55
What can you tell me about these guys all over my lawn in Albuquerque for the past week? They are about 3" long and eating the grass and/ or spurge on my lawn. They are yellow with red and black spots with a stripe down both sides. Wish I could include photos...
<span>Roxane</span> Wed, 08/21/2013 - 07:45
I draped bird netting over my plants to keep the birds off the tomatoes and chilis, and found it has the added advantage of keeping the tomato worms away. The mesh is big enough to let the pollinating insects through, but keeps the large Mandunca moths out.
<span>Juliette Paskowitz</span> Tue, 08/20/2013 - 10:26
Now that gigantic green worms ate all of my lovely tomatoes my grandson found a huge worm in the soil After I had remove the destroyed plant. So my question is. Can I plant some other plant in this same soil and Not have these creatures destroy??
<a title="View user profile." href="/author/editors">The Editors</a> Wed, 08/21/2013 - 15:25

Tomato hornworms are the scurge of tomato growers. The larvae burrow into the soil to pupate and emerge next spring as a moth. You can plant in the same soil—but not plants of the same famiy. Practicing crop rotation, as well as introducing natural enemies (parasitic braconid wasp, for example) can help to relieve the problem.

Some folks suggest that growing your tomatoes in containers can minimize the presence of hormworms. Remember, too that crops in containers (or the soil used) also should be rotated for best results.