How to Prevent and Get Rid of Cabbage Worms Organically

Cabbage worms can wreak havoc on your garden, especially if you grow plants from the brassica family like cabbage, kale, broccoli, and collards. If you’ve ever spotted small green worms munching through your leaves, you know how frustrating it can be. But don’t worry—you can prevent and get rid of cabbage worms organically with a few simple strategies.

Understanding Cabbage Worms

Cabbage worms are the larvae of small white butterflies, often called cabbage moths. They lay eggs on brassica leaves, and when the larvae hatch, they start feeding on the foliage. Left unchecked, they can completely ruin your crops.

The first time I encountered cabbage worms was on my kale plants. I had just planted them in May, and by June, I noticed tiny holes spreading across the leaves. Finding those worms tucked inside the curly kale was nearly impossible. My husband joked that it was “extra protein,” but I just couldn’t stomach the thought of eating them!

That’s when I set out to find natural ways to keep them away—and after much trial and error, I’ve found methods that truly work.

How to Prevent Cabbage Worms Naturally

1. Use Row Covers for Protection

One of the best ways to prevent cabbage worms is by using floating row covers. These lightweight fabric covers create a barrier that prevents moths from laying eggs on your plants. However, they must be used properly to be effective:

• Ensure the row cover has no holes. If you find small tears, use duct tape to repair them. Too many holes mean it’s time to replace the cover.
• Pin down the edges securely. I’ve used landscape pins, rocks, PVC clips, and metal clips—my personal favorite is these metal clips for a tight seal.
• Monitor for wind exposure. If the row cover is loose or lifted by wind, moths can slip in and lay eggs. Make sure it’s secured tightly!

2. Plant Early to Stay Ahead of Pests

Timing your planting can also reduce cabbage worm infestations. I start my brassica seedlings indoors 12 weeks before the last frost and transplant them outdoors 8 weeks before the last frost, covering them with row covers immediately. This allows the plants to grow and mature before cabbage moths become active.

⭐ Pro Tip: Since early spring can still bring frosty nights, use a medium weight row cover to create a microclimate that stays about 5°F warmer than the outside air. If a hard frost is expected, place a plastic sheet over the row cover for extra insulation.

3. Choose Fast Maturing Varieties

Another key to avoiding cabbage worms is choosing varieties that mature quickly. The longer a plant takes to grow, the more time it’s exposed to pests.

For cabbage, my top choices are:

• Golden Acre – Forms compact, quick-growing heads.
• Red Express – Produces small, flavorful red cabbage with minimal pest damage.

These varieties are ready for harvest sooner, meaning they have less exposure to cabbage moths and worms.

What If You Already Have Cabbage Worms?

If you notice signs of cabbage worms (holes in leaves, frass, or the worms themselves), here’s how to get rid of them organically:

• Handpicking: The simplest method is to manually remove worms. Check the underside of leaves and pick off any larvae you see.
• Neem Oil Spray: A natural insecticide that repels pests without harming beneficial insects.
• Diatomaceous Earth: Sprinkle food grade diatomaceous earth on plant leaves to deter and dehydrate worms.
• Companion Planting: Grow plants like thyme, dill, or marigolds nearby to deter cabbage moths.

Why I Avoid BT (Bacillus thuringiensis)

BT is a commonly used organic pesticide that targets cabbage worms. While it’s considered safe, I personally prefer not to spray my plants if I don’t have to. With the right prevention methods—row covers, early planting, and variety selection—you can successfully grow brassicas without relying on pesticides.

Cabbage worms can be a challenge, but with proper prevention and organic treatment methods, you can keep them under control and enjoy healthy, vibrant plants.

Key Takeaways:

• Use row covers for protection.
• Plant early in the season to avoid peak moth activity.
• Choose fast-maturing cabbage and broccoli varieties.
• If worms appear, handpick, apply neem oil, or use diatomaceous earth.

With these organic strategies, you can get rid of cabbage worms naturally and keep your garden thriving! Happy gardening from Sow Haven!