Invasive Worms Are Spreading Across the U.S.—How to Identify Them and Protect Your Garden

The Invasive Worm Threat Harming U.S. Gardens and Forests

A new species of invasive earthworms is spreading across the United States—and while they may look harmless, their impact on gardens and ecosystems is anything but. Commonly referred to as jumping worms, these fast-moving creatures are disrupting soil quality, harming plant life, and raising concerns among gardeners and scientists alike.

This guide explains what jumping worms are, how to recognize them, and the steps you can take to help stop their spread.

What Are Jumping Worms?

Jumping worms—also known as Asian jumping worms, Amynthas worms, or snake worms—originate from East Asia. They were unintentionally introduced into the U.S. through soil, mulch, and potted plants. Today, they are found throughout the Midwest, Northeast, and are expanding into southern and western states.

Unlike common earthworms, jumping worms move vigorously when touched, writhing and twisting in a snake-like fashion. They also feed on surface-level organic matter rapidly, leaving behind a coarse, nutrient-poor soil that resembles used coffee grounds.

How to Identify Jumping Worms

Look for these signs in your garden:

• Soil texture: Loose, grainy, and coffee ground-like soil.

• Worm appearance:

  • Gray-brown to black color

  • Up to 8 inches long

  • Highly active when handled

  • Smooth, light-colored band (clitellum) closer to the head than in native earthworms

Why Jumping Worms Are a Concern

Though small, jumping worms can cause widespread ecological disruption. Here’s how:

• Deplete soil nutrients by consuming organic matter too quickly

• Damage plant roots, which affects garden and forest health

• Disrupt beneficial microbes and fungi in the soil

• Outcompete native earthworm species, reducing biodiversity

As they spread, they increase the risk of erosion and reduce the soil’s ability to retain water and support vegetation.

How They Spread

Jumping worms reproduce without a mate, producing cocoons that can overwinter and hatch in spring. These cocoons are tiny and often travel undetected in:

• Mulch, compost, and soil

• Potted plants from nurseries or plant swaps

• Soil stuck to gardening tools, boots, or equipment

This makes human activity a primary factor in their spread.

What to Do If You Find Them

If you suspect jumping worms are in your yard, follow these steps:

1. Test your soil: Mix 1/3 cup of ground mustard seed with 1 gallon of water. Pour over a small area. Worms will rise to the surface if present.

2. Remove them: Collect the worms in a sealed bag. Freeze the bag overnight or dispose of it in the trash.

3. Treat the soil: Cover affected areas with black plastic in full sun for several days (solarizing) to heat and kill eggs and worms.

4. Disinfect tools: Clean your tools and footwear after working in affected areas.

5. Buy responsibly: Source compost, mulch, and plants from certified suppliers who screen for invasive species.

How You Can Help

Fighting the spread of jumping worms requires public awareness and coordinated action. You can:

• Report sightings to your local agriculture extension office or invasive species network

• Share information with fellow gardeners and landscapers

• Support native plant landscaping, which encourages healthier soil ecosystems

• Participate in local workshops or clean-up events

Conclusion: Protecting Your Soil Starts with Awareness

Jumping worms may be relatively new to the U.S., but their impact is already being felt in backyards, parks, and forests. With early detection and proper prevention, you can help limit their spread and protect native plant and soil life.

Every effort counts—and your garden can be part of the solution.