7 Natural Ways to Effectively Get Rid of Tomato Hornworms
It can be very stressful to suddenly wake up to a tomato plant getting decimated pretty much overnight, especially if you spent months growing it. One of the common suspects for such damage is tomato hornworms. Here is a full list of ways for you to get rid of them naturally!
Tomato hornworms can naturally be removed from plants without the use of chemical pesticides by 1) handpicking them, 2) hosing them down, 3), tilling the soil, 4) buying trap crops, 5) introducing predators, 6) applying diatomaceous earth, and 7) using organic pesticides. Only apply pesticides as a last resort for serious infestations.
As pesky as they are, fattened-up tomato hornworms turn into hawk moths once adults. But before they provide any benefit to your gardener by pollinating plants, they can quickly eat up your tomato plants!
1. Handpicking
The most effective way to naturally get rid of tomato hornworms is to simply handpick them from affected plants. Caught worms can then be disposed of or set free far away.
Here’s the thing, I know that there are home gardeners that love plants but hate bugs.
The thought of having to manually pick up each pesky hornworm off of tomato plants can be incredibly off-putting for some (in my case I love most insects, except cockroaches). Keep in mind that they neither sting nor bite, they just wriggle so no reason to be scared!
Learn about other common pests that damage tomato plants!
You don’t even have to touch them directly to remove them. Simply putting on thick gloves before plucking them by hand, should do just the trick. But you may need to do this more than once if you have multiple tomatoes next to each other.
For most cases, handpicking hornworms from plants is enough to stop them from causing further damage to tomato plants, especially if there are only a few of them.
Spot them easier by inspecting your tomatoes late in the afternoon or early in the evening with some black lights. They’ll practically glow with the light, making them quick to see.
Once all the tomato hornworms in your garden have been successfully caught, the decision of killing or letting them live ultimately falls on you.
You can end their misery by simply placing them in a bucket of soapy water, feeding them to birds like chickens, or using them as bait for fishing. Alternatively, you could take them far away from your property before letting them live out their short lives.
If you’re still undecided, simply placed them all in an old plastic container or glass jar.
2. Hosing Down
Tomato plants can be hosed down to naturally remove hornworms. Do this early in the morning to allow the plant to dry completely by the afternoon. Handheld sprays and water guns can also be used.
Frankly, having to handpick each tomato hornworm can be a tedious task if you have tons of tomato plants—of varying cultivars and varieties. Adding water into the equation makes them stick out more from the physical agitation.
Now, if you don’t want to spend hours checking underneath every leaf to make sure you don’t leave any eggs or young larvae behind, give your plants a good hosing down!
You could also hit the tomato hornworms you can see on the plant with water from a spray bottle to make them fall off.
To make it more fun, ask your younger siblings or kids to take them down using water guns—you could make a game out of it!
When you’re done, you can collect fallen bugs with a broom and dustpan. Don’t leave them right next to your tomatoes after shooting them down with your hose, sprayer, or water gun.
Otherwise, they can easily climb back up and continue feasting on the tender leaves, buds, and even fruits of your tomato plants!
3. Tilling the Soil
Get rid of tomato hornworm larvae and pupae naturally by tilling the soil after each harvest and at the start of spring before the plants resume actively growing.
This is one of my favorite ways to get rid of most, if not all, hornworms hiding in their gardens.
More specifically, soil tillage is a great solution for people with recurring hornworm problems in the garden, especially when the first two options don’t work well enough.
You see, mature tomato hornworms burrow into the ground so that they can pupate. The good thing is, they stay quite shallow underneath the soil-dwelling
Mature tomato hornworm larvae only burrow to about 4–6 inches (10–15 cm) of soil so tillage is an effective way of naturally killing up 90% of them!
Ideally, you should till your after every harvest for this to be truly effective. Then, at the start of spring do it again to get rid of hornworms overwintering in your soil—regardless if you are growing annuals or perennials.
4. Buying Trap Crops
Buy and place trap crops such as jimsonweed and tobacco near tomato plants to attract hornworms away from the tomatoes, naturally preventing further damage.
If you don’t have any other plants that can host tomato hornworms yet, then now is the perfect time to buy some, even in a pot to place nearby your tomato planted in the soil if outside.
When dealing with ongoing hornworm issues, you need to have mature plants. Otherwise, your tomato may be fully eaten up before the plants grow.
Common trap crops for tomato hornworms include:
- Horsenettle
- Jimsonweed
- Moonflower
- Nightshade
- Tobacco
Although other plants such as eggplants, peppers, and potatoes are also part of the Solanum genus and can be considered hosts, I wouldn’t place them near affected tomatoes.
Because while they may stop devouring your tomatoes, they’ll still devour the leaves and fruits of these plants. So it’s best no choose non-fruiting trap plants to get rid of hornworms.
Just don’t forget that you will still need to eventually physically remove or spray pesticides onto tomato hornworms even after they are on trap crops. If you don’t, they’ll end up returning to your tomatoes again once they’ve demolished all your available trap crops.
5. Introducing Predators
Despite being a bit more difficult to put into practice, attracting and/or introducing natural predators of tomato hornworms such as birds and wasps can efficiently help get rid of them will little direct intervention.
Because tomato hornworms are juicy soft-bodied caterpillars, there are a lot of predators that can keep them in check for you.
For instance, having bird feeders and baths in the garden can help you lure blackbirds, bluejays, finches, mockingbirds, robins, and other bigger carnivorous birds.
It will also serve you well to add plants that will attract beneficial insects to feed on pesky tomato hornworms so that you don’t have to pick and kill them yourself. More on this in a bit.
Aside from these, you can also buy and release natural predatory insects such as ladybugs (here on Amazon). Buy them from online shops or local gardening stores.
Below are some insects that can help get rid of and manage tomato hornworms:
- Braconid wasps
- Green lacewings
- Hyposoter wasps
- Ladybugs or ladybeetles
- Paper wasps
- Trichogammid wasps
These insects will feast on tomato hornworms in different stages of their life. So it’s best to have a few, if not all, of them in your garden. Just remember not to use any pesticides that may kill these helpful little critters!
What are the white capsules on tomato hornworms?
The white capsule-looking things on tomato hornworms are the egg sacs of the parasitic braconid wasps. Once found, they should be left alone and not discarded as the wasp larvae will feed on and kill hornworms from the inside. Doing so will also ensure a constant population of these natural predators in home gardens for natural pest control.
6. Applying Diatomaceous Earth
Gardeners can naturally remove and kill tomato hornworms without using pesticides by applying diatomaceous earth on affected plants. However, this can also kill beneficial insects such as honeybees.
Even though it feels like fine powder, diatomaceous earth is made of thousands—if not millions—of tiny abrasive fossilized shells of aquatic plants referred to as diatoms.
I like using the packaged diatomaceous earth from Amazon below. You can even buy it with a duster for a couple more bucks.
You don’t have to look hard to find packs of it. Local hardware stores and garden centers normally sell them. Then just place them in a regular salt shaker or use a sifter to apply them to your hornworm-infested tomatoes.
Diatomaceous earth works by wounding soft-bodied insects such as tomato hornworms, resulting in the loss of their bodily liquids. Despite not being poisonous, ingesting it also causes them to dry out from the inside before dying.
Make sure to wear a mask while doing this to avoid inhaling it. Also, you could moisten the undersides of leaves by spraying some water on them and then putting some diatomaceous earth. Let it dry after that and it’ll do its job.
I’ve also heard of other people using all-purpose flour, ground black pepper, as well as cayenne pepper for this. However, people share mixed results and I couldn’t see any evidence to support this.
With the spices, I could see some logic to them acting as irritants but I’m not too sure that they can effectively remove tomato hornworms.
7. Using Organic Pesticides
In cases where there are roughly more than 2 tomato hornworms per plant, an organic pesticide like Bacillus thuringiensis or spinosad can be used to naturally get rid of them. This is rarely ever necessary for small-scale vegetable gardens.
When none of the earlier methods have gotten rid of the tomato hornworms, and you still see 2 or more feasting on each plant, it’s time to consider using a naturally derive pesticide. This is because just 2 hornworms can completely defoliate tomato plants in only a day or so.
Now, if you’ve already thought about this you’ve probably seen a lot of DIY recipes for tomato hornworm sprays using things like chili peppers, garlic, neem oil, and castile soap.
Find out which pests you can successfully repel neem oil with!
They are, however, not as effective as biological pesticides containing either Bacillus thuringiensis (Bt) or spinosad. Both of these are natural soil-borne bacteria that can be very toxic to insects like tomato hornworms.
If you’re lucky enough to spot newly hatched and young tomato hornworms, use the kurstaki strain of Bacillius thuringiensis. The larvae will die after ingesting it. This works with many other troublesome caterpillars too, including cabbage worms.
Directly spritz ready-to-use Bacillus thuringiensis sprays or dilute concentrates like the one below from Amazon. Make sure to follow the manufacturer’s instructions for dilution!
Now, if you spot larger hornworms or you’re dealing with serious infestations, spinosad (here on Monterey) would be the better option. It can help you deal with hornworms through ingestion or direct contact with treated tomato plants.
Spinosad affects the nervous systems of insect pests like tomato hornworms. This bacteria paralyzes and inevitably kills them.
How to Avoid Pesky Tomato Hornworms (5 Tricks!)
Avoid having hornworms infest tomato plants with 1) regular checking, 2) weeding, 3) companion planting, 4) crop rotation, and 5) small and big plant covers.
Being home gardeners, it can be difficult to control and resolve serious tomato hornworm infestation—especially if you’re also busy taking care of your family and doing your job. So in this case, as the old saying goes, prevention is better than cure!
1. Checking
The best way to prevent tomato hornworms from wreaking havoc in your garden is to regularly check on your plants. By doing this, you’re more likely to nip the issue in the bud and avoid having to deal with serious cases of hornworm infestations.
Check for their tiny eggs (0.04–0.08 in or 1–2 cm) underneath the leaves of your tomato plants. Hawk moths will typically lay 1–5 eggs on a plant per visit.
Start doing this early in spring. If you aren’t able to spot them early on, you may see their larvae popping up around July to August.
2. Weeding
It’s also important to remove weeds around your tomato plants—regardless if they’re in pots, raised beds, or directly in the ground.
Weeding regularly makes sure that there is little to no place for hawk moths to lay their eggs, thereby stopping potential tomato hornworm problems.
3. Companion Planting
Growing plants that attract natural enemies of tomato hornworms, including a variety of predatory wasps, will help you prevent having to experience major plant and fruit damage.
The best companion plants for tomatoes to repel hornworms are;
- Angelica
- Basil
- Borage
- Catnip
- Carrot
- Celery
- Chives
- Coriander
- Dill
- Garlic
- Horehound
- Marigold
- Mint
- Onions
- Parsley
- Parsnip
- Tansy
Place these around your tomato plants so that these live plants can act as natural repellents for hornworms and many other problematic pests.
4. Crop Rotation
Another great preventive measure for tomato hornworms is crop rotation, especially with larger home and vegetable gardens.
Similar to intercropping and companion planting, crop rotation helps draw in beneficial insects and repel unwanted damaging ones.
Moving your tomato plants around the garden also lessens the likelihood of having tomato hornworms repeatedly, year after year. Just make sure not to replace their old spots with other hornworm hosts such as eggplants and peppers!
5. Plant Covers
If you want to go for a time-saving and more practical way to prevent getting tomato hornworms on your plants, then having physical barriers will be efficient.
You could use regular plant covers for individual tomatoes, especially potted ones—whether they’re kept indoors or outdoors. I’ve also seen some home gardeners make their own covers out of cheesecloth and fine plastic mesh.
But if you have dozens of different tomatoes growing at the same time, look into buying and building a mini greenhouse.
FAQs
Are black lights effective for getting rid of tomato hornworms?
Even though black light traps attract hawk moths, adult tomato hornworms, they are not as effective in removing the young and mature larvae from the plants they are infesting. But they can be used for preventing future infestations as capture moths can’t lay their eggs under the leaves of tomato plants. Such traps can also harm beneficial insects.
Can you compost tomato hornworms?
It is not recommended to add tomato hornworms to compost piles. Though some gardeners report having done so successfully without any issues, it’s best to simply get rid of tomato hornworms completely to prevent reinfestations.
Where do tomato hornworms go during the day?
Tomato hornworm larvae typically hide during the day underneath the leaves. Because of this, they’re hard to find without close inspection, especially since their green coloration allows them to blend in with plants. But early in the morning and late in the afternoon, they will go out to eat. They may also be found through their dark droppings.
Summary of Natural Ways to Get Rid of Tomato Hornworms
For the most part, physical methods of removal are enough to solve tomato hornworm problems. They can be picked from affected plants by hand, hosed down with water, or killed when the soil is tilled. Buying trap crops can also stop them from defoliating tomato plants.
With more serious cases of tomato hornworm infestations, gardeners can introduce natural predatory insects like ladybugs and wasps or apply diatomaceous earth on affected plants.
The use of pesticides, even organic ones, is only necessary when more than 2 hornworms are present on each tomato plant. The two most effective naturally derived pesticides are Bacillus thuringiensis and spinosad.
Sources
- “Tomato hornworms in home gardens” by Jeffrey Hahn and Suzanne Wold-Burkness in the University of Minnesota Extension
- “Hornworms” by Russell Groves in the University of Wisconsin-Madison Division of Extension
- “Hornworms” by n/a in the Statewide Integrated Pest Management Program, University of California Agriculture and Natural Resources
- “Tomato Hornworm and Tobacco Hornworm” by Nick Volesky and Marion Murray in the Utah State University Extension
- “My Nemesis” by Mary B. Gabbard in Agriculture and Natural Resources, University of California
- “Bacillus thuringiensis (Bt) kurstaki and israelensis strains” by n/a in the Missouri Botanical Garden
- “Alternative Pesticide Options for The Home Gardener” by Andrew Brischke, Bob Clotworthy, Jeff Schalau, Hattie Braun, and Michael Wierda in The University of Arizona Cooperative Extension
