Controlling Garden Pests Naturally and Organically

Tomato Horn Worms

Tomato Hornworms are the larva of a huge moth called five-spotted hawkmoth. Approximate size of the moth is around the size of a hummingbird so you can’t miss them. The hawkmoth is gray-brown with yellow spots on the sides of their body.

horn-worm2_1.jpg hornworm_hawkmoth_1.jpg
Tomato Hornworm-(left) Colorado State University, Five-spotted hawkmoth (right)-Floridagardening.com

The hornworm caterpillars are pretty small at first and hard to see because of their pale green color, but they become huge – 3 1/2 to 4 inches (7-10cm) in 3-4 weeks. You can’t miss them then! They are green-brown colour with v-shaped markings on the body and unmistakable ‘horns’. Hornworm eggs are green and are laid on the underside of leaves.

Tomato Hornworm Pupa (Cocoon) hornwormegg_1.jpg
Hornworm Pupa (cocoon), Hornworm Egg (right)-Colorado State University

Hornworm Lifecycle
The five-spotted hawkmoths lay their eggs as soon as they mate after hatching. They appear in late June to August. Full grown larva (3-4 weeks feeding) wander around the garden digging themselves in where they form a pupa (brown and about 3cm long) that overwinters and hatches in the spring.

hornworm4_1.jpg
Hornworm Damage-Floridagardening.com

Hornworm Damage
Tomato Hornworms feed on leaves and stems of tomato plants. Ocassionally they will also eat the fruits later in the summer months. They also feed on peppers, eggplant and potatoes. They can defoliate a plant in just a few days. There can be two generations of tomato hornworms every year. A bunch of them can spell disaster in your garden!

How To Control Tomato Hornworms

  1. Use a liquid Bt spray like Green Step™ Caterpillar Control-
    Bt (Bacillus thuringiensis) does not harm animals, people or the environment. It paralyzes the horn worms and they die from starvation. Spray the top and bottom of the tomato plant leaves. Repeat every 5 to 7 days until you don’t see anymore worms. Bt is safe to use right up to the time of picking your tomatoes.
  2. Another all-natural environmentally friendly pesticide that is safe for use around kids and pets is Plant Guardian™ Houseplant Insecticidal Soap-
    Spraying the undersides of the leaves with an insecticidal soap mixture kills the eggs at the first sign of seeing the moths. A hard spray of water will also help if your plants are strong enough. Wiping the eggs off with alcohol on a q-tip is also effective.
  3. Introduce Parasitic Wasps into your garden-
    Parasitc Wasps (Braconid and Trichogramma) lay their eggs on the larva. If you see little white things on the worm don’t kill the worm, place it in a jar with a fresh leaf and keep feeding it until the wasps do their job. These are the cocoons of the wasp and their larva feed inside the host and will kill it. This guy below has just met his maker!
    hornworm3_1.jpg hornworm5.jpg
    Hornworm with parasite eggs (left)-Joe Boggs, Braconid Wasp (right)-Perdue University
  4. Hand Pick
    Tomato Hornworms are so big you cannot miss these guys. If you don’t want to touch them I recommend cutting them in half with the kitchen scissors. In the fall when you turn your garden pick out any pupae (cocoons) you might find and destroy them.
  5. Companion Planting
    Plant marigolds as a deterrent around or between your tomatoes. Marigolds stink to a lot of different bugs and they avoid them.

511 Responses to “Tomato Horn Worms”

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  1. 450
    Sami Says:

    What in the world would possess somebody to have a Hornworm for a pet? It’s not going to come when you call it! It won’t Sit, Stay or Roll Over. All it does is eat plants! I have a lot of lizards around my yard, they Love the hornworms. I pull the worms from the plants and put them in a dish they can’t get out of, but the lizards can get to them. I’m doing my part in helping along the “Food Chain”. :-)

  2. 449
    Hannah Says:

    Heh, yeah, I actually BOUGHT one to keep as a pet believe it or not, and, as I recently found out, it is a ton of work!!!! I got it a tomato fruit, but apparently it prefers the leaves, it’s cool though, it’s a tobacco one.

  3. 448
    Sami Says:

    I am in Florida where it is virtually impossible to just plant ANY veggies, especially tomatoes, and expect any good results. The soil is bad and every disease & bug is just waiting for the plants to come up out of the ground. The Tobacco Horned Worms are the WORST! After many hours every day, I managed to grow 4 beautiful tomatoe plants with Hundreds of beautiful healthy blooms and the foliage was awesome! Every day I would pollinate the plants and 4 weeks into my anticipation of seeing fruit, I went out to check them, and OMG!!! Foliage was gone on many limbs and I pulled off 11 Horned Worms! I had NO problem squashing each and EVERY one of them. My family is more important to me than a damn worm! :o )

  4. 447
    andrew Says:

    ok we just got a hornworm from my tomato plant and its allmost dead what do i do to get it back up? oh and i got the horn worm as a pet now :D

  5. 446
    Elaine Says:

    (to the commentors who think it’s cruel to hurt /kill these worms)

    Good God people! Get your priorities straight. These worms don’t have more rights than you. They can kill your plants. Ever had the cat “provide” for you, wake you up in the night with a huge bird sized moth in their mouth and placed on your lips, while the cat howls at you to wake up? I have and still do. It’s no fun and gross. Don a glove, pick it off, fast pitch it into the fence and don’t look back.

    (to the rest of us)
    Re: garden pests
    You’re gonna have pests.
    When they eat more than you do, then you’re going to need to do something like spray or get / encourage the meat eaters like toads, praying mantis, spiders, etc.,. (don’t kill them, ruin their webs, you get the idea) if you don’t try to control it, you WILL eventually lose your garden and food.

    Tree huggers, what about the poor plants? Sheesh!

  6. 445
    Lisa Says:

    The first thing I noticed was all the droppings on the ground…I had no idea that those huge worms were on my plants. I actually was setting out to prune my overgrown tomato plants when we discovered them…the kids had lots of fun causing them to “click” before sending them to the manure yard.

  7. 444
    Rose Says:

    I have the hornworm in my garden also. They are not in my tomato plants, They are in my moonflowers. I dont kill them either, They turn into a beautiful moth. What everyone here that has trouble with them. Ask your friends and neighbors, For seeds from there moonflowers.

  8. 443
    Sue Says:

    Ugh. I just remembered where I got my CSI instincts. I think I was a budding serial killer. My brother and I used to torture these hideous worms when we were kids. I have since redeemed myself however. I am now a teacher and plan to use the ones I picked off of my bell peppers for science. And explain why we should not torture living creatures…snicker snicker.

  9. 442
    Al Says:

    =Years ago, I would go crazy when the tomato worms appeared. Here in SoCal, our summer eve’s are relatively warm making it not only ideal for the tomato plants but for the worms also. I remember one morning I came out to find one of my tomato plant completely de-forested. It looked like a skeleton. And hiding on the underside of the naked branches were about four HUGE worms. I got so pissed off, I picked them off, placed one on a 2×4 and slammed it with the sledge hammer. I should have done what I always did before and do today which is cut them in half with scissors.
    When I smashed the worm, yep, you know it, it splatted in my face!
    Please dont use chemical to kill the worms, regardless of how safe they claim it to be, just pick them by hand and destroy them on site.

  10. 441
    Ron Says:

    Thanks for the advice about marigolds, garlic and red peppers.

    I learned to pick them and to throw them hard on the driveway. Don’t have chickens yet.

  11. 440
    Gary from Maine Says:

    So far good news! I’ve gone two whole days without seeing one worm, my plants are sprouting leaves again and my tomatoes are finally starting to turn red. Hopefully the worst is over however I’m not holding my breath! I check at least twice a day now, I’m just paranoid. Like others next year I’ll pay better attention to them and use some prevention early on..

  12. 439
    Kitty Says:

    We have 20 tomato plants ….they were big and beautiful and full one day, the next..skeletons!… we picked off 145 horn worms over one week period. The damage was done, but it looks like they will recover somewhat. In the end we resorted to dusting with ($%&^*(#$%). next year we will remember to look under the leaves from day one!

  13. 438
    Zang2nd Says:

    Went out this afternoon…Four of those suckers very nearly killed four pepper and four tomato plants overnight! 60% of the leaves were devoured, and several peppers. I’m sure the ants are going to love those juicy little bastards…

  14. 437
    Gary from Maine Says:

    I too just came across them for the first time. Wondering why my tomato plants all of a sudden looked stripped and quickly found out why. These guys were perched on the stripped branches working their way down I guess. I took some real neat picture of them eating then removed and squished them, about 9 or 10 on 4 plants. I see why they poop like they do as their bodies are full of “green” food (my plants) from head to toe. They’re like a giant fast food processor, in then out in minutes! All my worms were about 4+ inches so were very mature. I saved one for my grandson but got out by morning somewhere. Found one more (the one I had saved?) next day attached to to branches and disposed of him. Only found two real small ones two days later. I did find some copper eggs on one leave and removed them. Now wondering what I’ll be finding in the up and coming days. Nothing has touched my peppers …. yet!

  15. 436
    James Says:

    What’s more fun is having a chicken yard to toss them in. The chickens love ‘em. I find it very satisfying.

  16. 435
    Ariel Says:

    1. Thought a storm that had gone through had somehow stripped all the leaves off my plants (like tornadoes with trees) As if the 113 degree weather here hasn’t been enough to deal with.. noooo I look up and have this “thing” practically in my face…gross.. it has friends… double gross.

    2. They fight me as I am trying to pull them off… vulgar language and screaming like a little girl didn’t seem to help at all. Armed with a one glove and pliers I go in. Still won’t let go! I get frustrated and just grab them with my hand (gloved of course) and throw them in a tv dinner box.

    3. I start jumping up and down on the box in glee at my accomplishment, only to be rewarded with green slime shooting out both sides of the box. Sometimes you just can’t win.

  17. 434
    Justaworm2 Says:

    Yall, Oh my goodness, its a stinking worm!! If you didn’t kill it, or nothing else killed it, it would go out of proportion, and could do even more damage. Just kill it! Don’t be a tree hugger!! It is just a worm!! If anything feed it to the chickens so you don’t feel bad about killing a measly little worm!

  18. 433
    tj Says:

    I used a couple of my kid’s fire crackers. I haven’t seen the worms since.

  19. 432
    DNM Says:

    I got a bunch of these on my tomato plants. Everyday I diligently looked for them and picked them up. A good way to find them is notice their damage. You will see stems stripped of leaves, and you will find a worm on it or close by. After removing the worm also cut off the damaged stem.

    This way it will be easier to find new damage and new worms. If you check daily after a few days most will be gone. Also think about adding plants that attract wasps that prey on them. Other than that I don;t know what else to do to control them. This is the first time I had them and I think I did a good job controlling them. You have to get a jump on this early before they cause any big damage. I must of caught about 30 worms so far that ranged in size from 1-4 inches.

  20. 431
    Woodswoman Says:

    The hornworms may be an important part of nature’s life cycle but I think there are plenty to go around. I either pinch them or cut them up with the clippers I keep in my garden. They literally ate my bellpeppers to the core earlier this year. They defoliate the tomato plants which is really bad in this summer’s heat. I want to protect plants that I nurture and hope will produce something for ME to eat. I am appalled, however, at the gleeful and immature comments some people have posted on this subject. What’s next for them, purposely killing animals and people? Such attitudes have become a problem in our society…so sad.

  21. 430
    Justaworm Says:

    People, its a stinking worm that will eat your tomato plants and waste your money, just chop the sucker up and leave it at that! stop being tree huggers. Come on people get a life. And it hardly has a brain so it doesn’t feel much!!! I picked them off and fed them to chickens at a place I went to, they just peck them until they die, haha! I thought it was funny the way the chickens played with the worms! I am not cruel its just a worm. It’s the circle of life. Granted they are pretty cool looking but they eat the plants which is why you just kill the darn thing. Come on people get a life, I was looking at this because my grandfather wanted to know what they turned into, and I read some of the comments and was like come on you people!! Anyway its just a worm kill it!!

  22. 429
    Linda Says:

    My garden is surrounded with marigolds. The hornworms didn’t care.

  23. 428
    sunshine Says:

    So I just read that using garlic powder and red pepper flakes works at keeping “the big green monsters” out of your garden,is this true? I have 15 tomatoe plants and they are all pretty much dead. I have one near my back door and I did see a couple of the worms and picked them off but I did not see any in my actual garden. I must have overlooked them perhaps cuz they have been ate up by something and there are no leaves left just stems. I’m very confused and I’m not sure at this point that I can save my plants but for next year if garlic and pepper flakes works I will certaintly give it a try.

  24. 427
    Dawn Says:

    Thank you for this info! I was just out in the garden today tending to the plants and almost put my hand on one of the little guys! Wasn’t sure what they were until I started to google about them. I found a few on my plants, I have an all natural organic pesticide (safe around pets and children) that I may try spraying this evening after the sun is off the plants. I am going to pick the ones off I see but my plants are really big and I won’t be able to find all I am sure.

  25. 426
    Janice Says:

    Running over, squishing the caterpillars is a ‘deeply environmentally aware’ solution?! Deeply disturbed is more like it. Right – no pesticides. They morph into these amazing, large, beautiful moths! I just trimmed the non-budded 6- 10 inches of tomato plant with accompanying caterpillars (22!) and took them across the stream into a shady wooded area on our property. Don’t know if that will be a place where they can continue their life cycle without my garden, or if they’ll be back, or what. I have just 16 plants – hand-picking wouldn’t work in a bigger garden.

  26. 425
    cody Says:

    this ones to cool to kill..got him in a jar and no wasp..feed him a new leaf every other day…

  27. 424
    Pat Lynch Says:

    Do these moths lay their eggs before you buy the tomato plant or when they are in my garden? I have never seen this moth. Last year for the first time, I bought tomato plants at a Blue Seal. These worms decimated the plants. I bought tomato plants at the same place again (shame on me) and my husband just removed SIX worms. I have never had them before in the 10 years I have lived here!

  28. 423
    JHR Says:

    Here’s a method my deeply environmentally aware friend taught me back in the 70′s. He was a vegetarian, Buddist, surgical nurse living with my sister in Denver. Had a rather large garden with maybe a dozen tomato plants. One day when I was visiting he asked me to help him get rid of his hornworms. I had never seen one before. He entered the garden armed with a surgical clamp and grabbed each worn by the scruff of it’s neck and tossed it onto the adjacent driveway. When he was done there were about 25 of the critters on the driveway, all making their way back to the garden. Then he went into the house and came out with the keys to my sister’s 230 horsepower V8 plymouth and proceeded to run over them with it. It took several passes to get them all. He explained that he didn’t believe in pesticides.

  29. 422
    Linda Powers Says:

    I have hornworms on
    my tomatos Is there anything that kills the worms but well not hurt all the honey bees that are all over my garden?

  30. 421
    Kathy Says:

    I agree with Lila Lyons…How can anyone torture anything like the examples given. That is obsurd..they are living creatures and getting eaten alive is morbid. Stick netting on the plants…good grief…how cruel can you people be…and i think they are beautiful.

  31. 420
    stephanie Says:

    i have seen these worms before, not only on tomato plants and the like, but also on moonflower leaves. i have 2 plants, a big boy and a beef master, and found my first worms today. big ones! 14 of ‘em! to those of you that have only found a few, KEEP LOOKING!!! remember, moths don’t lay “a few” eggs!:)

  32. 419
    Lila Lyons-Werner Says:

    I am so glad to see so many people on here with a heart. The idea of torturing ANYTHING to death by starvation or being eaten alive by parasites seems ludicrous to me. I read that planting Marigolds around the plants will keep them away too. I’m going to try that and maybe the garlic too.

  33. 418
    Lara Jenkins Says:

    I understand that people want to keep these guys off of their plants but the whole wasp thing just seems so cruel!! Kill them quick if you are going to do it at all.

  34. 417
    Babs Says:

    We only have two plants, Early Girls and Sweet 100′s. We started
    seeing evidence of these worms yesterday, so far we have found 6. 5 were on the early girl. Very small. Should I expect more? This is crazy…

  35. 416
    Denise Says:

    Hi Everyone,

    I found a different way to control these guys. I drape black bird netting over my tomato plants. The bees can still get in, but the moths lay their eggs on the netting and the bright green color makes them really visible. I remove the eggs whenever I find them…..usually around the time of the new moon. I am sure i miss a few, but the harm one or two larvae can do is not huge. Feed them to my chickens when I do find them. They absolutely love them!

  36. 415
    Rosemary Says:

    My husband just killed a big fat one that was feasting on my mater plants. Ick.. they’re so fat and squishy! I’m thinking saline fluid or super glue, lol.

  37. 414
    Adam Says:

    I just found huge hornworm on one of m Roma tomato plants today. Luckily my handheldbug zapper (a 3.3 million volt stun gun) make short work of it. Hopefully I won’t see too many more since I only have 6 plants total. I’ll have to try the red pepper flakes. I have raised beds and we use cayenne pepper to keep th dog out of them and it worked pretty well.

  38. 413
    melissa Says:

    Can anyone help me???? I have over 300 tomato plants. I have what I think to be “alternaria canker” and “horn worms”. I don’t want to spray but I can’t pick every infected leaf off of 300 plants. I need help!

  39. 412
    Albert Dziennik Says:

    I use tat bug bombs like you use inside the home to fumigate. Turn the can upside down and aim while slightly pushing the button in (not enough to lock it in the on postion, though). The worms drop off to the ground and die. Plus the leaves are coated with the pyrmithrin. Permithrin is a by product of the chrysanthimum so it’s okay. The stuff quickly works on the worms nerve center and causes inability of the worm to continue to eat or live. It works almost instantly for quick relief. The fogger also goes deep into the plant with ease for total protection. Spray as often as needed throughout the season. You can get the foggers at Walmart, Kmart, Family Dollar etc. Doom to the parasitic worms!!!!

  40. 411
    Rebecca Carroll Says:

    We have them all over our Tomato Plants and We would like to kill them so they won’t kill our Tomato plant

  41. 410
    Laura Says:

    Last fall, I found lots of hornworms on plants at the edge of the pond in my packyard. My husband usually keeps the weeds trimmed pretty well but left some of the plants the caterpillars were eating. I put two of the caterpillars in bug boxes about half full of dirt and fed them leaves. After a couple of weeks, the caterpillars burrowed into the dirt and made their chrysili. They emerged and turned out to be pink-spotted hawkmoths. I released them onto the moonflowers in my front garden. My grandkids and I really enjoyed watching the caterpillars. This year, I found some tomato hornworms on my tomato and pepper plants. I was able to spot them right after they had hatched by seeing their frass on the plant’s leaves. I picked them off by hand and also removed some of their eggs. I may keep one or two caterpillars to watch the cycle again, but I wish I could put them on other plants outside. I like the moths, but I don’t like the caterpillars eating my tomatoes.

  42. 409
    alvin Says:

    where to acquire hornworm chow?

  43. 408
    amy bean Says:

    I don’t want to kill the hornworm on my tomato plants. i read one post which said you can get hornworm “chow”. where can i get it? (quickly, before it eats my entire plant!) thanks.

  44. 407
    Sharon Says:

    For those that thought watching these delightful creatures is good for children, you are absolutely correct. Any time that we can give children hands-on experiences with nature is a plus. These can actually easily be purchased from a company, Mullberry Farms for use as reptile food. As a science teacher I use them in my class. They are easily grown, require little care and you can also get hornworm chow so they are not eating your tomato plants to pieces. Place them in a container of your choice, however there needs to be ventilation so that they can breath and so that mold does not grow on the food that you are feeding them. Because they are very hardy, the children can actually hold them without damaging them unless of course they squeeze them and well that is another experiment in itself. The chow makes it easy and you can have them all year around. I have found that putting them in a warm place (the same with silk worms) that they grow much faster. I use a warming lamp such as I use with reptiles with a low wat bulb and it warms the aquarium nicely – on a timer so that it simulates day and night (for the off times I have a red lamp) well anyway they grow beautifully with little loss. Once the moths emerge you can actuall keep the cycle going if you can feed the moths – they need to eat soon after hatching and warming their body. If you have a chance to do this with chidlren it is wonderful.

  45. 406
    Cheryl OKeefe Says:

    Is there any way to get them? I have been growing tomatoes every year but I havent seen one for about 15 years. My daughter wants to see them so bad.

  46. 405
    cyBrew Says:

    <> I use cactus around, or near the base of the plants you want to save!

  47. 404
    ted in yakima Says:

    Dorothy

    And every time you do that you introduce another group of kids to real science in action, and to the mystery of life and the beauty of the incredible Creation we all enjoy.

    What a wonderful example of turning “Lemons into Lemonade”

  48. 403
    Dorothy Says:

    As a preschool teacher we had a garden kept by our maintance man. He would bring me three or four of these gorgeous creatures for my kids to watch. If you want to keep them and study the life cycle do this: Get a plastic cage or tank from a pet store about 12 or 15 inches long and 10 inches deep. Size will Depend on how many you have. The best kind to raise are the ones that you find which are hudge! I mean BIG! That means they are ready to go into the ground where the form a crysalis. Keep them on top of the soil in your tank for a day or two by feeding them fresh leaves everyday and a green tomato or the fruit of the plant you found them on.

    If you have too many in a single cage they get nasty and will die so give them room (maybe only two/tank). Oh yes, fill the cage with about four inches of loose soil(soil mixed with some sand to avoid soil from becoming compacted) After a day or two they will drop off the leaves and dig into the ground. They do this at night so I have never seen them dig. They are just gone the next morning. If you dig you will find them. But leave them after you have confirmed they did indeed bury themselves. After 3 weeks you can empty the soil and you will find the dark brown chrysalis. It is very exciting to imagine how this fleshy green thing turns into this hard shell encasement.

    In 4 to 5 weeks depending on the room temperture you will come to in your room find a hudge brown moth trying to flutter. This is a really exciting moment for children and adults. The whole school is watching and waiting for this moment. We take the tank outside and I lift him out and put on my hand and they shake their wings causing their “blood” to circulate through out their wings. And they fly away. Its amazing!

    Before that

  49. 402
    Patty Says:

    LindaLu,

    What do you do if you have a dog who digs everything insight? The idea is great for my front yard, but I have a Jack Russell who picks trangerines off my tree and buries them EVERYWHERE. Have tried commercial products only to burn the life out of the plants. Any ideas? BTW, I found another critter on my bell pepper plant yesterday. Man, those things don’t quit.

  50. 401
    LindaLu Says:

    This was my 1st experience w/these big green monsters… Yuk! But not wanting to use any pesticides, I plucked off all the ones I cld see – gave ‘em to the chickens, who were fightin’ over ‘em – I went back outside and got some red pepper flakes and garlic powder and sprinkled that all around the base of my nearly stripped clean jalapenio and bell pepper plants (no tomatoes – but they were in full force over on my daughter’s tomatoes across the driveway!) and I sprinkled some of the garlic and red pepper flakes on the leaves too. I thought the plants were goners, but the leaves grew back just as lush, w/lots of wonderful bellpeppers and jalapenos, and NO MORE HORNWOMRS! But I am going to dig around in the raised bed just before winter hits and seek out any pupae – and next spring I’m gonna use the garlic/pepper flakes on the soil before I see any cuz I just know they’re down there somewhere!

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