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Rid Your Garden of Tomato Hornworm Caterpillars – Naturally!


All spring you worked your perfect yoga-sculpted butt off to ensure your organic garden would be successful. It’s summer and your garden harvesting is in full swing. While weeding your garden’s tomato bed, you notice a gigantic, horned green caterpillar clinging to one of your beautiful tomato plants.

Blech – right? These creepy green monstrosities are unappealing to the eye and deadly to your garden.

Tomato hornworms (Manduca quinquemaculata) – also referred to as tobacco hornworms – love tomato plants (they also fancy peppers, eggplants and potatoes) as much as you love organic dark chocolate. The tomato pests chow down on plants producing green fruit and one worm can take down your organic foliage and fruit in one night.

Any good gardener knows (and who are we kidding; you're the best gardener on the block) that the first line of garden defense is to know your enemy.

Crash course in Hornworm-ology

The tomato hornworm is a caterpillar that’s native to the United States. The pest can grow up to 4-inches long and its horn is ornamental. If a hornworm matures, it becomes a large moth that pollinates night blooming flowers.

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From the Organic Authority Files

Get a Handle on the Situation

You can carefully go through your garden by hand and remove any hornworms you find. If the thought of touching these green beasts gives you the heebie-jeebies, slide on your gardening gloves and grab the pest, or grasp the worm with a pair of tweezers. Sure, you can kill the hornworm in a bucket of soapy water or save it for fish bait for that family camping trip you've planned later this month (ah -- vacation!). Or, you can let nature do the work (see below)!

Call in Tomato Hornworm Fighting Friends

Everyone and everything has an enemy. This truth is no different for our garden’s archenemy. Small, parasitic wasps (trichogramma) lay eggs on tomato hornworms' backs that eventually hatch into larvae, create cocoons and eat the hornworm for nourishment. Yes. Nature is gross, but these wasps are essential in ridding your plants of these pesky caterpillars. Never kill a hornworm with small, rice-sized pellets in its back. Let those wasps hatch and naturally rid your garden of these pests.

Wasp Friendly Foliage

Mike McGrath, question of the week answerer from Gardens Alive!, a company that sells environmentally responsible gardening products, suggests planting foliage that attracts parasitic wasps.

"(The wasps) like a little nectar and pollen to cleanse their palates in between caterpillar meals, especially from tiny flowers that grow in umbrella-like clusters, like dill, fennel, Queen Anne’s lace and biennials like carrots and parsley left in the garden for a second year. They also like compound, daisy-like flowers, tansy, spearmint, clover, sweet alyssum and many others.”

You’re now hip to how to control the tomato hornworm population in your garden. Now, it’s time to move on to more important tasks. Start prepping those worm-free tomatoes for the Hale Kale Salad you’re cooking for tonight’s dinner party. Hop to it!

image: hornworm

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