All that hard work – and it is paying off. Your vegetable garden looks perfect – except for the caterpillars that are feeding on your tomatoes, lettuce, cabbage, collard greens, kale, fresh herbs and beans – most likely these are corn earworms. If you notice that new shoots are chewed off at the base – cutworms are responsible for that. They may be small – but they do eat a lot – even flowers. Tent caterpillars are the ones that spin web masses in trees and can completely defoliate a tree.
Caterpillars are the larvae of moths and butterflies. There are several different species. For instance – the pale green caterpillars that have stripes running down their backs are cabbage loopers that munch on collard greens, kale and lettuce leaves. They are the larvae of brown and green moths.
Trying to get rid of caterpillars organically is possible. For instance, plant your garden early and make sure it is fertilized and well taken care of and you have beaten the caterpillars to the punch. Place cardboard around the base of all your plants.
You can hand pick the caterpillars out of the garden, but even if you remove 20 from your lettuce today, by tomorrow you can find another 20 more. And you run the risk of not getting them all and having no plants left the next day. Using an old coffee can or ice cream bucket, fill half way up with water and squirt in about ¼ cup of dish detergent. Pluck them off and place in the solution to drown. And remember to check under the leaves where they hide.
If hand-picking is not for you, try placing sticky bands around the base of the plants or spray with an organic pesticide. There are biodegradable or organic pesticides that are out there that are non-toxic. Just read the labels carefully before using.
You can always leave them alone and let them eat what they want and you settle for the rest. They usually eat the outer leaves and leave the rest alone – except with herbs – they won’t leave you any. I don’t feel that sharing my garden with caterpillars is something I would like to do. I wouldn’t want to find one that made its way into a salad!
You could always introduce a predatory pest into your garden, such as lizards, frogs or wasps. That will control the caterpillar population for sure.
Try some good organic gardening methods that will give you healthy plants and naturally fight off pests. Rotate your crops, plant a companion plant, do not plant your vegetables in rows, or build up your soil by adding compost and mulch.
Bacillus thuringiensis (BT) can be used for controlling caterpillars. It’s probably the number one way of getting rid of caterpillars. It’s a bacteria that infects and kills caterpillars by destroying the lining of the guts. It is effective only on caterpillars and will not harm anything else. Just spray on foliage and let them eat it. Be sure to buy BTK (the “K” stands for kurstaki).
If you have tent caterpillars in a tree, get a good long stick and pound a few nails in it and scrape the nest right out of the tree. Poke the stick into the nest and start spinning and scraping. Do this either early in the morning or late at night when they are in their nest. If you can reach by pruning, pull the branches down and saw off. Dispose of as you see fit. Burning is one option. Place in an aluminum trash can and set on fire with a bottle of charcoal lighter fluid.
Neem oil is a natural oil from the neem tree that can get rid of caterpillars immediately. The taste so bad that when sprayed on foods the caterpillars eat, they won’t touch it. They would rather starve.
Pyrethrins are also effective when sprayed. Look for Take down and Rotenone-Pyrethrin Spray.
An insecticidal soap will dissolve the protective layer, or “cuticle” of insects, destroys cell membranes causing cell contents to spill out. Try Safer Insecticidal Soap and Garden Safe.
To prevent caterpillars, spray your trees with dormant oil in late fall or winter to suffocate the insects that are lying dormant in the bark. Use Eco-Oil and All Seasons Horticultural & Dormant Spray Oil. You can also use duct tape or aluminum foil and make a band around the trunk of a tree and coat it with petroleum jelly, or Tree Tanglefood Pest Barrier.