How To Get Rid Of Green Caterpillars

If you’re seeing holes in your leaves and small green worms on your plants, you need to learn how to get rid of green caterpillars. These hungry pests can quickly damage your garden, but you don’t need harsh chemicals to stop them.

This guide will show you effective natural control methods that are safe for your plants, your family, and the good bugs in your garden. We’ll cover everything from simple hand-picking to homemade sprays and clever garden tricks.

Before you start, it’s helpful to know what you’re dealing with. “Green caterpillar” is a general term for the larval stage of several moths and butterflies. Common ones include cabbage loopers, tomato hornworms, and inchworms. Identifying the exact type can help you target your efforts, but many natural methods work against all of them.

Start With Inspection and Hand-Picking

This is the most immediate and effective method for a light infestation. Go out to your garden in the early morning or evening when caterpillars are most active.

Wear garden gloves if you prefer.
Check the undersides of leaves, along stems, and near new growth.
Drop any caterpillars you find into a bucket of soapy water. They will drown quickly.

Do this daily for a week to break their breeding cycle. It’s suprisingly effective for larger caterpillars like hornworms.

Introduce Beneficial Insects and Animals

Nature provides its own pest control. You can attract or buy insects that prey on caterpillars.

Birds: Put up bird feeders and a birdbath to invite them into your garden. Chickadees and sparrows are especially helpful.
Parasitic Wasps: These tiny, non-stinging wasps lay eggs on caterpillars. You can attract them by planting nectar-rich flowers like dill, fennel, and yarrow.
Ladybugs & Lacewings: Their larvae consume caterpillar eggs and young larvae.

Use a Natural Bacterial Spray: Bt (Bacillus thuringiensis)

Bt is a naturally occurring soil bacteria that is completely organic and highly specific. It only affects caterpillars and is harmless to other insects, pets, and people.

Buy Bt kurstaki (Bt-k) from a garden center.
Mix it with water according to the package directions.
Spray it thoroughly on the leaves of affected plants, especially the undersides.
Caterpillars ingest the bacteria and stop feeding within hours.

Reapply after rain or every 7-10 days as needed. It’s one of the most reliable tools you have.

Apply Diatomaceous Earth

Diatomaceous earth (DE) is a fine powder made from fossilized algae. It feels soft to us, but it’s sharp on a microscopic level, damaging the exoskeleton of soft-bodied insects like caterpillars, causing them to dehydrate.

Use food-grade DE only.
Dust a thin layer on dry leaves where caterpillars crawl.
Reapply after watering or rain, as it washes off easily.
Wear a mask when applying to avoid inhaling the dust.

Make Homemade Pepper & Garlic Sprays

These sprays create a taste and smell barrier that repels many pests. Here’s a simple recipe:

Blend 2-3 hot peppers and a full bulb of garlic with 2 cups of water.
Strain the mixture into a spray bottle.
Add a teaspoon of liquid castile soap (this helps the spray stick to leaves).
Test on a small part of the plant first, then spray liberally.

Remember to reapply frequently, especialy after it rains. Avoid spraying on very hot, sunny days to prevent leaf burn.

Neem Oil: A Dual-Action Solution

Neem oil is a versatile plant-based oil. It works as both a repellent and an insect growth regulator, meaning it can disrupt a caterpillar’s life cycle.

Mix neem oil concentrate with water and a little soap as an emulsifier. Spray it on all plant surfaces every 7-14 days. It works best as a preventative measure.

Set Up Physical Barriers

Stopping caterpillars from reaching your plants is a foolproof strategy.

Floating Row Covers: Lightweight fabric placed over plants blocks moths from laying eggs. Secure the edges tightly with soil or pins.
Cardboard Collars: For stem-based plants, make a collar from cardboard or aluminum foil and place it around the base to deter cutworms.
Copper Tape: Some gardeners find that copper tape around pots or raised beds deters slugs and some crawling insects.

Practice Companion Planting

Some plants naturally repel pests with their strong scents. Interplant them with your vulnerable crops.

Plant herbs like sage, rosemary, and mint near cabbages and broccoli.
Marigolds and nasturtiums are famous for repelling a variety of pests and can act as a “trap crop,” attracting caterpillars away from your main vegetables.
Onions and garlic scattered through the garden can also help mask the scent of your other plants.

Keep Your Garden Clean and Tilled

Good garden hygiene removes the places where pests hide and overwinter.

In the fall, remove all dead plant debris where pupae might hide. Turn the soil in late fall to expose any buried pupae to birds and cold weather. Rotate your crops each year to prevent pests from building up in the soil.

FAQ: Natural Green Caterpillar Control

What kills caterpillars naturally?

Hand-picking, Bt (Bacillus thuringiensis) spray, and diatomaceous earth are three of the most effective natural killers. Encouraging birds and predatory insects also provides long-term control.

How do I keep green caterpillars off my plants?

Prevention is key. Use floating row covers as a physical barrier, practice companion planting with strong-smelling herbs, and apply neem oil or homemade garlic sprays regularly to deter egg-laying moths.

Will soapy water kill caterpillars?

Yes, a direct spray of soapy water can kill smaller caterpillars by suffocating them. A mix of 2 tablespoons of liquid soap per gallon of water can be used. It’s less effective on larger, hairier caterpillars and needs to contact the insect directly.

What is the fastest way to get rid of caterpillars?

For a sudden, visible infestation, hand-picking is the fastest immediate action. For broader, ongoing control, spraying Bt is the quickest and most thorough natural solution, as it stops feeding rapidly.

Are any green caterpillars good for the garden?

Yes! Some green caterpillars turn into beneficial pollinators like butterflies. For example, the green caterpillar of the Black Swallowtail butterfly feeds on parsley, dill, and fennel. If you can, relocate these instead of destroying them, if they’re not causing major damage.

Managing green caterpillars naturally requires a bit of patience and consistency, but it’s very achievable. Start with the simplest methods like inspection and hand-picking. Combine that with a strong preventative strategy using barriers and companion plants. For tougher cases, keep Bt or neem oil ready. By working with nature’s systems, you can protect your garden and enjoy a healthy, chemical-free harvest all season long.