How To Protect Tomato Plants From Hornworms
“Hornworms” is a common but misleading moniker for larval hawk moth caterpillars. Proper naming aside, hornworms are brutal pests, and they can wreak havoc on the tomato plants in your garden. You’re not alone if you’d like to protect your tomato plants from hornworms.
Manually remove large hornworms you find and drop them into a dish of soapy water to kill them. If you’d rather not touch them, you can spray them with neem oil or insecticidal soap. Till the soil around your tomato plants to kill hornworm pupae and prevent them from emerging.
Hornworms can’t harm you, but they’ll keep damaging your tomato plants until you do something about it. Follow along as we explore how to protect tomato plants from hornworms and how to quickly get rid of them.
How To Get Rid Of Hornworms On Tomato Plants
1. Manually Remove Them
This may not work if you’re squeamish, but you can protect tomato plants from hornworms by removing them by hand. Hornworms are big and distinct and easy to see, but sometimes, they blend in with the leaves, so you may need to inspect the tomato plants closely to find hornworms. While they can’t hurt you, you should at least wear gloves before handling them.
Before going outside, fill a bucket or a dish with mild soap and warm water. Manually remove the hornworms and drop them into the dish to kill them. Repeat this process indefinitely until you no longer find hornworms. You may miss some larvae, so make sure to look at the underside of the leaves. Check tomato plants early in the morning to find as many hornworms as possible.
2. Attract Ladybugs
Ladybugs may look cute and harmless, but they’re actually fierce predators and may be your best bet to protect tomato plants from hornworms. While you can buy ladybugs, you can also easily attract them to your garden in many climates. Ladybugs won’t prey upon mature hornworms, but they will eat the larvae on your tomato plants. This will prevent larval hornworms from maturing and damaging the plants.
You can attract ladybugs by planting pollen-rich plants, like marigolds, dill, calendula, and yarrow, in your garden. It’s also a good idea to install a fountain or place some water dishes near the tomato plants. Don’t use pesticides in the garden, or else ladybugs and other beneficial insects will avoid the area.
3. Spray With Neem Oil
Neem oil is easily the best natural insecticide, and many would argue that it’s the only one you should use. After all, commercial insecticides can harm you, your plants, your pets, and the environment. This oil comes from the neem tree, and is processed into an organic vegetable oil. You can use neem oil to disrupt or kill over 200 types of pests, all without harming your plants. Neem oil typically kills insects on contact, and it doesn’t take much.
The key is to put 1-2 teaspoons of neem oil in a spray bottle or bucket with ½ teaspoon of dish soap and a quart of water. Thoroughly mix the solution, then spray the affected tomato plants. Target areas where hornworms are most active, and don’t forget to spray the undersides of the leaves. That way, you can also kill the larvae before they mature.
4. Till The Soil
Hornworms use tomato plants as hosts, and then burrow into the soil when they mature. They go as deep as 6”, where they can then lie dormant for a while. You can protect tomato plants by tilling the soil to stop the pupae from emerging later. Tilling involves turning over the soil and aerating it to improve moisture retention and keep weeds at bay. Early spring is the best time to till the soil, but you can also do it during early autumn.
By tilling the soil, you can destroy the dormant pupae overwintering in the ground. That way, they won’t have the chance to surface and wreak havoc on your tomato plants. Even if you don’t kill them, you’ll at least expose them and leave the hornworms vulnerable to the elements. You should till the soil in your garden at least once per year.
5. Attract Braconid Wasps
You may be thinking, “Why would I attract wasps to my garden?”, and that’s a fair sentiment. However, braconid wasps aren’t exactly like the wasps you’re probably imagining right now. Braconid wasps rarely sting humans, but they love to kill hornworms. You and your pets are safe from braconid wasps, but the hornworms on your tomato plants are in extreme danger.
That’s because braconid wasps act as parasitoids and lay eggs inside of hornworms. Eventually, the larvae will hatch and eat the hornworm. The best way to attract braconid wasps is to plant cilantro, parsley, dill, fennel, yarrow, daisies, and sunflowers. They’re more active in areas with wetlands and lots of crops. Braconid wasps won’t immediately destroy the hornworm population, but they will help protect your tomatoes and other crops.
6. Grow Companion Plants
Hawk moths, which produce hornworms, have a strong sense of smell. You can use that to your advantage by growing aromatic plants to deter hawk moths, and ultimately, hornworms. You can stop hawk moths from producing hornworms on your tomato plants by growing basil and marigolds. These plants are aromatic enough to deter many pests while also sprucing up your garden. Starflower, also known as borage, can also help protect your tomato plants from hornworms.
The key is to grow aromatic plants as close to your tomatoes as possible. Luckily, most of these plants can also deter other pests and attract beneficial predators. However, you may want to treat your tomato plants with neem oil while you wait for your new plants to grow. That way, you won’t have to worry about hornworms destroying your tomato plants.
7. Set Up A Bird Bath And Bird Feeder
Many people attract birds to enjoy their natural beauty. Others attract birds to their yards to get rid of pests such as hornworms. Birds are fierce predators, and they can help protect your tomato plants from hornworms. The easiest way to attract birds is to set up a bird feeder and a bird bath. Put some black oil sunflower seeds in your bird feeder to attract as many birds as possible.
That said, research which birds are most active in your area and attract them with their favorite food. Install your new feeder and bird bath near your tomato plants for the best results. It’s also a good idea to plant some shrubs to create a comfortable atmosphere for the birds. Otherwise, they may feel vulnerable to predators.
8. Use Insecticidal Soap
Insecticidal soap is a natural substance derived from plant and animal oils and fats. This unique pesticide can kill bugs by breaking down their waxy armor and dehydrating them. That said, you must be careful because insecticidal soap can damage tomato plants and other crops. However, it shouldn’t kill your tomato plant like other pesticides would.
That’s especially true if you’re careful and mostly apply the soap in spots where hornworms are most active. Keep in mind that it may be difficult to kill large hornworms with insecticidal soap. The smaller hornworms and larvae will likely die shortly after being exposed. Be as direct as possible, because the soap won’t kill the hornworms unless you hit them with it.
How Long Do Hornworms Live?
Hornworms live up to 4 weeks before entering the pupal stage. It takes them roughly 50 days to go from the larval stage to becoming a hawk moth. That’s why you must act so quickly, as having more hawk moths around will only yield more hornworms.
At one point, you may notice fewer hornworms on your tomato plants and think they have left. However, there’s a good chance they entered the pupal stage and burrowed into the soil. You can’t count on hornworms and hawk moths to die naturally, so don’t try to wait out their lifespan.
Summing It Up
Manually remove large hornworms whenever possible and spray the rest with neem oil or insecticidal soap. It’s also a good idea to attract predators, like ladybugs, braconid wasps, and birds, to control the hornworm population. Plants, like dill, fennel, basil, marigolds, and starflowers, can also help get rid of tomato hornworms.
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Nick Durante is a professional writer with a primary focus on home improvement. When he is not writing about home improvement or taking on projects around the house, he likes to read and create art. He is always looking towards the newest trends in home improvement.
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