You wander out to the garden to pick some fresh tomatoes. You find small black droppings on the leaves of your tomato plant. The leaves are gone, but the stem remains. Looks like you probably have tomato worms. Tomato worms feast on the leaves of your tomato plants, which will lead to the plant dying.
The tomato hornworm (Manduca quinquemaculata) is a large caterpillar that can grow to be up to 6 inches long and almost an inch in diameter. They eat a variety of vegetables from the Solanaceae family of plants, such as eggplant, peppers, and potatoes.
The caterpillar, when allowed will become the five-spotted hawkmoth. The hawkmoth is yellow and black spotted body and gray wings with a muted design.
Spotting The Tomato Hornworms on the Plant
The first way is to check to see if you spot the caterpillars themselves on the plant. Hornworms can be tough to spot at first because they are very well camouflaged. Their coloring tends to blend in very well with the leaves. Be sure to check very closely. Be sure to check under the bottom sides of leaves too. This is one of their great hiding places.
If you have seen defoliated plants, but don’t see the hornworms, know they are there. A natural way to find them is to mix up a batch of liquid castile soap and warm water. Place ¼ cup of the soap into a spray bottle that is at least 16 ounces. Spray the tomato plants with the dissolved solution. The hornworms do not like the soapy mixture. They try to get out of the way, and this makes it easier for you to spot them.
Removing and Disposing of Tomato Hornworms
If you do find hornworms on any of your plants in the garden, remove them quickly. Using gloves or hormworm tongs, pick them off, and drop them into a bucket of soapy water. Gloves, tongs, or other hands off pulling methods are recommended hornworms can give off a dark liquid when picking them off the plant.
Go chickens? They consider it a treat if you feed them the worms.
You can also step on them. If you are a little squeamish about stepping on them, you can also use a large rock to kill them. If this is still a little too much for you, get a large coffee can and put a little gas, or kerosene in it. Drop the hornworms into the can. Once they are dead, you can pick them out, and toss them in the trash. You can reuse the can of kerosene all summer long.
Natural Ways To Rid Your Garden of the Tomato Worm
The best natural predator of the tomato horn worm is the Braconid and Trichogramma wasps. These tiny wasps lay their eggs on the worm, and the eggs use the worms for food as they hatch. The tomato worms are used as a sort of nursery for the wasp eggs. As they hatch, they feed on the worm, which kills it. Don’t worry, these wasps don’t bother with people. Once they hatch, you would never notice them. To invite these wasps into your garden, plant herbs and flowers such as dill, clover, sweet alyssum, and fennel. If you use these plants in your garden as companion plants, the wasps will come and lay eggs.
Tomato worms love dill. Predator wasps love dill. By planting dill plants near your tomatoes, it will deter the worms, and attract the wasps. You will save your prized tomatoes. The light foliage of the dill also makes it easier to find the hornworms.
Other Natural Methods of Controlling Worms
Be sure to always rotate your crops in the garden every year. Never plant tomatoes or any member of the nightshade family in the same place every year.
Cover the soil around your tomatoes with a black plastic. Covering the soil can help prevent the laying of eggs on your plant.
Natural Insecticide for Tomato Worms
If you are looking for a natural insecticide to kill those nasty tomato hornworms, look no further than your rhubarb plants. Rhubarb leaves contain oxalic acid which kills the worm. Wearing thick rubber gloves, make a strong tea or infusion from the leaves. Heat leaves for about 25 minutes. Strain out the leaves, and pour the liquid into a 32 ounce bottle. Spray the tomato plant before it flowers. You can also spray around the base of the plant. Be sure not to spray the fruit. Be sure not to reuse the vessels you use to make this, for cooking or eating. Oxalic acid can be very dangerous when taken internally. Oxalic acid, when taken internally by humans, or pets can be fatal.