It is hard to not see a tomato hornworm because of their color and size. This worm is not one you want around your garden.
It will strip the leaves off a tomato plant in just one afternoon. Although they are hard to get rid of, it is not impossible and organic methods work very well to free your garden from these voracious worms. It just takes a little work on your part.
Tomato hornworms are also called tobacco hornworms they also eat tobacco leaves. They consume foliage from some peppers, eggplant and potatoes (members of the nightshade family). Hornworms are a striking-looking caterpillar that turns into a moth gray and brown moth.
They are a bright spring green grow up to 6 inches long and can be 1 inch in diameter. Their body is segmented with dots on the side and they have a little orangish colored hook at their end giving them the name of “hornworm”.
Caterpillars hatch in early summer and feed for about 4 to 6 weeks. The cocoon overwinters, hidden in the soil. The moth comes out in early springs and starts laying eggs.
Finding the Hornworm
Check plants every day for an infestation. You will know if there is one because you will see chewed leaves with just veins being left. The worms are the same green as your tomato leaves so you really have to look for them.
Check the tops and bottoms of the leaves and look on the ground for droppings that look like tiny rabbit droppings; dark brown to black pellets. If you spray your plants with soapy water, the hornworm will wiggle around in convulsive style and you will be able to see them. If you touch a hornworm, they tend to turn around in your hand and eject dark brown to black liquid. Wear gloves.
Organic Methods Of Destruction
There are several methods of organic destruction of these pests that will not hurt anything and your crop will remain chemical free.
Hand Picking is the most common way to get rid of hornworm although this is time consuming and there always seems to be another hornworm under the next leaf. As said before, wear garden or plastic gloves to pick them because they will squirt you with their nasty liquid.
You can use tweezers if you prefer not to touch them. Throw them in a bucket of soapy water and proceed to squish them. Put them on the ground, put a board over top and step on it if you don’t have the nerve to squish with your fingers. Some people even use them as bait for fishing.
Beneficial Insects are a possibility to control tomato hornworm. Parasitic wasps lay their eggs on the hornworm backs and these eggs hatch and the larvae attach themselves and eat the hornworm alive.
If you every see a green hornworm with little white sacks sticking up like a porcupine, that is the baby wasps in cocoons dining on the hornworm. Avoid killing hornworms with the cocoons on their back because you want those baby wasps to mature.
Other Beneficial Predators include robins and mocking birds. They love to dine on tomato hornworm so be sure to put some bird baths and bird feeders around the vegetable garden to keep them coming back.
Make your own repellent by soaking 6 cloves of crushed garlic in 1-gallon water with a few squirts of dishwashing liquid and 1 teaspoon cayenne pepper. Strain out the garlic after 2 days and put the solution in a spray bottle that attaches to your hose to dilute the solution. Spray every week and after a heavy rain. Hornworm will not go near your plants.
Plant a large patch of dill in your garden but far away from the plants hornworm eats. This is used as a diversion. Hornworms love dill and they might stay away from your tomatoes and peppers.
Bacillus thringiensis (BT) is an organic pesticide that is safely used around vegetable. Mix it with water per the package instruction and spray it on tomatoes, peppers, eggplant and potatoes. When eaten by the hornworm, it causes loss of appetite and it will die. This substance only kills insects that eat leaves so your bees will be fine.
It is possible to prevent infestations of tomato hornworm several ways. It takes some vigilance and persistence, but it pays off in the end.
When tilling in the spring, where nightshade species grew the year before, look for pupae of the hornworm. They look like brown sacs that are torpedo shaped and tube-like. Have fun trying to catch them, but if you do, treat them as you do the caterpillar by throwing them in soapy water and squishing them.
Rotate your crops in your vegetable garden and avoid planting nightshade vegetables in the same spot every year. Instead of planting tomatoes and peppers on the south side of the garden, switch this year to the east side.
Cover the garden under nightshade plants with black plastic mulch. The moth will have a hard time getting through the plastic to mature and lay more eggs. It will be trapped in the ground and die.
Tomato hornworm is controlled in several different ways picking them off to using beneficial insects and other predators to mixing up your own safe pesticide. Don’t hesitate to combine methods because hornworms are crafty.
You may need two, three or even four methods to keep them from eating the foliage in your garden. With persistence, you will have a great harvest and enough vegetables to can or freeze and keep you through the winter.