01 Aug Pests in the Garden: Tomato Hornworms
An inevitable part of managing a garden is dealing with pests, and we’re no stranger to them here at ifarm. We recently found several tobacco hornworms in our tomato plants, seen in the picture above. Tobacco and tomato hornworms differ in coloration, but have the same diets and life cycle. These large, green caterpillars can destroy tomato plants, along with any plant in the Solanaceae family. This includes peppers, potatoes, tobacco, eggplant and even the poisonous Jimsonweed. Even just a few caterpillars can do a lot of damage to your plants.
The Hornworm Life Cycle
A hornworm is the larval stage of the Sphinx Moth, a large and showy moth also known as a hawk moth. These caterpillars begin as eggs, laid by parent moths on the underside of leaves. When they hatch, they eat whatever they can reach and grow steadily larger until they are ready to form a cocoon. To do this, they bury into the ground, and remain there through the winter. In spring, they emerge as large moths, feed on flower nectar, and lay their own eggs to restart the cycle.
Managing Tomato Hornworms
The first, and perhaps hardest, step of managing hornworms in your garden is finding them. They are very well camouflaged, and blend in perfectly with green leaves. It’s often easier to find them based on the presence of their droppings, called frass. And because they are so large, the easiest way to get rid of them is handpicking. They can hold onto leaves surprisingly well, so you may need to cut off whatever branch they are clinging to. You can then drop them in a bucket of soap and water to kill them. Or, like me, you can keep one as a short-term pet in a small enclosure. If fed a steady diet of tomato leaves, they can survive in captivity until they are ready to overwinter in a cocoon. But do not release them as moths, as they will lay eggs and cause more problems in your garden.
Permaculture offers many techniques for managing pests without the use of harmful pesticides. To learn more, attend one of our Permaculture workshops, like our Companion Planting Workshop on August 17th.
For more information about hornworms, and how to manage them naturally, check out the links below.