How To Get Rid Of Hornworms? Top Tips

Are you looking for ways to deter or repel hornworms? Or are you seeking a guide on how to get rid of hornworms completely? Either way, this article will help you.

Notorious for devastating crops and plants, hornworms are true nightmares for farmers and gardeners. If you have a vegetable garden or an agricultural farm, you’ll likely encounter these green pests at least once. 

Hornworms are voracious eaters and need only a couple of days to destroy a plant completely. These relentless pests can eat up to 4 times their body weight every day. 

Thankfully, getting rid of these garden pests isn’t too hard. There are several ways to repel them, ranging from the manual removal of the pests to chemical treatments.

Should I Kill Tomato Hornworms?

As much as you might hate killing insects, you don’t have much choice when it comes to tomato hornworms attacking your plants. 

Remember, tomato leaves are not the only thing tomato hornworms munch on. They feed on a variety of other vegetables, too, including eggplants, potatoes, celery, etc. The nightshade plant species are particularly prone to hornworm attacks.

Ignoring a hornworm infestation in your garden can make all your work on the plants go to waste. As long as the garden has plants it can feed on; these garden pests will wreak havoc. 

The same goes for a tobacco hornworm infestation. You need to kill them as soon as you can. You can easily locate hornworms by looking for their black droppings on the plant’s leaves.

How To Get Rid of Tomato Hornworms Without Pesticides?

Gardeners often refrain from the use of pesticides, which is indeed sensible. Considering the potential side effects of pesticides on beneficial insects, they should be a last resort when natural methods fail. Let’s explore how to get rid of hornworms naturally:

1. Handpicking

Handpicking the hornworms off your plants is the simplest way to remove them. You may either feed the handpicked hornworms to birds or simply kill them yourself. 

You can easily identify tomato hornworms – they look like green caterpillars with black horns and white V-shaped markings.

2. Beneficial Insects

Releasing natural predators in your garden is an effective long-term strategy to deal with hornworms and other pests that can damage your plants or crops. Ladybugs, lacewings, and parasitic wasps are some of the beneficial insects that kill hornworms.

Parasitic wasps such as paper wasps and braconid wasps use hornworms as hosts to lay eggs. Once the eggs hatch and the baby wasps grow through the larval stages, they feed on the hornworm’s body and ultimately kill it.

3. Predatory Birds

Having more birds in your garden is a good idea not only for the ambiance but also because the birds feed on pests. Some birds, such as Baltimore orioles, downy woodpeckers, flycatchers, bluebirds, and sparrows, are voracious hornworm eaters.

Setting up birdhouses, birdbaths, and bird feeders in your garden will invite more birds and help keep the hornworm population under control.  

4. Plant Trap Crops

As an alternative to handpicking the hornworms, you can use trap plants to draw them away. Take a nightshade plant and place it near the plants infested by hornworms. 

Once the pests move to this trap plant, you can kill the pests easily or dispose of the plant altogether. Tobacco plants are particularly good for trapping hornworms.  

5. Plant Dill

Like the other trap plants mentioned earlier, dill helps draw away the hornworms. However, it deserves special mention because dill also attracts predatory insects that kill hornworms. This makes it very effective at trapping and killing hornworms naturally.        

6. Floating Row Covers

Installing floating row covers or high tunnels over your plants will bar hornworm moths from reaching them at all. 

This way, you don’t have to worry about the moths laying hornworm eggs on your plants, which could hatch into hornworms and cause an infestation. Remember to remove the covers in time for pollination.

7. Ground covers

You may also cover the ground around your plants with a layer of black plastic mulch. 

Once the hornworms pupating in the soil mature into moths, this ground cover will prevent them from coming to the surface. They’ll die without being able to lay eggs for a new generation of hornworms.

8. Use Companion Planting

Companion plants like basil, borage, parsley, and marigold repel hornworms. Some companion plants also attract pollinators and insects that prey on hornworms. Interplanting companion plants in your garden will aid in pest control.

9. Crop rotation

Rotating your crops is always a good idea, for growing the same crop on a patch of soil repeatedly can drain the necessary nutrients from the soil. 

However, it also helps control hornworm populations by removing pupae in the soil, burying them too deep, or simply making it harder for the moths to find the crops.

10.  Till the soil

While pupating in winter, hornworms may hole up in the soil. Overwintering in the soil allows them to pupate safely. By spring, the pupae will mature into adult moths and fly off. 

This is why it’s a good idea to till your soil after a harvest. Do this at the onset of winter because it exposes the hornworm pupae to cold weather and kills them.

11. Spray Homemade Cayenne Pepper Spray  

Natural homemade insect repellants like cayenne pepper spray are a great alternative to chemical pesticides. Spraying it on the plants will repel hornworms and might even kill them. You can make the spray using water, cayenne pepper, and soap.

12.  Neem oil

Neem oil is one of the most effective natural pesticides, but does neem oil kill hornworms? Yes, neem oil is very good at killing hornworms, but it can also kill other beneficial insects. Try neem oil only as a last resort before switching to chemical pesticides.

How To Kill Tomato Hornworms With Chemicals?

In case you’re dealing with a large-scale hornworm infestation, and the natural methods fail to get rid of these green worms, you may have to resort to chemical pesticides. 

Choose your pesticide carefully and use it in carefully moderated amounts. Two of the most effective pesticides you can use to repel hornworms are:

1. Bacillus Thuricide (B.T.)

More commonly known as B.T., Bacillus Thuricide is a natural chemical obtained from Bacillus Thuringiensis, a soil-dwelling bacterium. B.T. is an excellent insecticide that kills pests by paralyzing their digestive system. The hornworms eventually stop eating and die. 

B.T. also deters cabbage loopers, cabbage worms, and other caterpillars. Moreover, it is safe to use as it doesn’t harm humans, kids, or other animals. 

B.T. is not quick acting. You have to apply it several times for it to work. It’s less effective in sunlight and dries off quickly, so it might be a good idea to apply it at night.

2. Monterey Garden Insect Spray

Like B.T., Monterey Garden Insect Spray is a biopesticide made with the help of bacteria. It contains Spinosad, which is highly effective for pest control. 

Using Monterey Garden Insect Spray will help you quickly and effectively eliminate the hornworms. Besides tomato and tobacco hornworms, this pesticide is also effective against moths, flies, borers, butterflies, leaf miners, caterpillars, etc.

Mix Monterey with water as per the specifications on the label. Spray it on both the top and bottom of the plants. Make sure only to mix as much spray as is needed for one use. This insecticide is harmful to bees, so don’t use it on plants that are pollinating.

How To Prevent Tomato Hornworms

Of course, it’s better to prevent a tomato hornworm infestation altogether than work on repelling the pests later. There are various preventive measures that you could try out to protect your plants from these pests. Let’s check out some of these.

1. Try Diatomaceous Earth

Diatomaceous Earth (D.E.) is both an insecticide and a repellant. Sprinkling this powdery substance on and around your plants will help deter hornworms. 

Diatomaceous Earth has the texture of broken glass and can easily shred the small bodies of these pests. Once the D.E. enters their bodies, it will cause them to dry up and die from dehydration.

2. Use Black Plastic

This method is similar to the use of black plastic mulch as ground cover. By laying sheets of black plastic over the soil, you can trap the pupating moths in the soil and prevent them from getting out. 

Eventually, they’ll die before even getting a chance to lay new eggs. You may also use a thick layer of cardboard as an alternative to black plastic.

Frequently Asked Questions

Will Soapy Water Kill Hornworms?

Yes, soapy water is also effective at killing hornworms. Moreover, a soap and water solution won’t harm bees and other beneficial insects in your garden, which makes it a better option than insecticides. Alternatively, you may also use insecticidal soap for this purpose.

What animal eats hornworms?

A variety of small insectivorous animals, like chameleons, leopard geckos, bearded dragons, scorpions, spiders, etc., feed on hornworms.

Hornworms have a high calcium and moisture content, so they are healthy food for most smaller insects and animals. They are low in fat and also have a decent amount of protein.

Where do hornworms go during the day?

During the day, hornworms hide beneath leaves. Their green bodies are perfect camouflage and allow them to blend in with the leaves. They come out in the evening to feast on plant leaves and are much easier to spot at twilight.

Will tomato plants recover from hornworms?

Yes, even if your tomato plants have suffered a hornworm attack, they will likely recover. You may help stimulate new growth by pruning the damaged branches and leaves. When you remove the leaves, the plant will produce new ones quickly from the existing leaves’ axils.

Wrapping up

Despite their dreaded reputation, you can easily get rid of them and protect your plants from future infestations. It’s best to remove hornworms before they can mature into hawk moths ( also known as hummingbird moths)

Hawk moths would lay more eggs in the hundreds, and those can hatch into new hornworm larvae very quickly, leading to a full-blown infestation. Thank you for reading!