Jumping Worms are Headed for Washington: What you Need to Know

You have probably never heard of Asian jumping worms, but this invasive species has been quietly spreading across the United States since the 1920s.

Right now, they are already established in Oregon across six counties along the I-5 corridor, and Washington state is next in their path. They cause damage to soil, gardens, forests, and native ecosystems, but you might not even notice it.

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The good news is that they are not yet common pests in Washington State. The bad news is that once they are established, they are nearly impossible to eradicate.

What Makes Jumping Worms So Different

Asian jumping worms are not your garden-variety earthworms. They are also called crazy worms, snake worms, and Alabama jumpers, and live in the top three inches of soil. They consume every bit of organic matter they can find.

A normal earthworm improves soil structure and water retention; jumping worms do the opposite. Their castings dry into hard, gravel-like granules that repel water, destroy soil structure, and easily wash away, creating what researchers call a nutrient-poor paradox: nutrients are present in the soil but not available to be used by plants.

These worms can infest up to 17 acres in a single year on their own. Regular earthworms migrate about 30 feet per year by comparison.

They also reproduce aggressively but do not even need a mate to do so. Each worm carries both male and female reproductive organs and lays tiny cocoons that survive winter, hatch in spring, and start the whole cycle over again. Think of them like super worms.

Adults die in winter, but the mustard seed-sized cocoons in the soil are nearly invisible and extremely cold-resistant. Washington winters do not get cold enough to kill them, so they just come back in the spring.

How to Identify an Asian Jumping Worm If You Find It

Regular earthworms are brown or dark peach in color. Jumping worms are glossy gray or light brown with one or two white clitellum, the band that circles the worm's body. On a jumping worm, it is milky white, completely smooth, and flat against the body. On every other worm species, it bulges outward and is a different color, like maroon or brown. That white, flat band is a for-sure sign that you are looking at an Asian jumping worm.

They also thrash violently when bothered, can slither sideways like a snake, and can propel themselves off the ground by maybe an inch.

Their castings also give them away, making soil that looks like coffee grounds on the surface. That texture is what infested soil looks like.

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How Jumping Worms Can Spread Into Washington

Jumping worms can easily spread through potted plants, mulch, compost, shared soil, and landscaping equipment. Their egg cocoons are the size of a mustard seed and look exactly like a tiny clump of dirt.

You cannot see them with the naked eye in a bag of mulch or in the soil around a nursery plant.

Hikers can carry them on boot treads, and gardeners can spread them when they share plants between neighbors. Fishermen spread them when they use jumping worms as fish bait.

If you find them in Washington state, report it to the Washington State Department of Agriculture immediately. Oregon's I-5 corridor is infested, and Washington is next door.

This is not a distant problem, but a backyard problem that just hasn't fully arrived yet.