Jumping Worms In Your Garden | Jung Seed's Gardening Blog

In my first job after college, I was working in someone’s garden and noticed something odd. The soil in their garden resembled coffee grounds and had an unusual, soft texture. Eventually, I found the cause of this mystery: Jumping worms.

Like other worms, jumping worms play a role in the health and structure of soil. However, their vigorous diet is causing problems in gardens across the eastern U.S.

With their large appetite, these worms remove organic matter from the soil and reduce the amount of nutrients available for the plants. In the forest, areas with jumping worms often have bare soil and less plant growth. And they have the same impact in gardens.

Note: Most earthworms in the Midwest are not native, but they’re still beneficial for gardens in moderation. Jumping worms are more aggressive and will create problems with soil structure and plant growth.

Life Cycle of Jumping Worms

There are still unknowns about the life of a Jumping worm, but we know their general life cycle. Depending on your location, the timing of these events will vary, but here’s generally what to expect.

April – May: The cocoons (overwintered eggs) hatch but are usually not visible.
Late May – June: Adults appear in small numbers but are often not noticed until later in summer.
August – September: Sightings of jumping worms are most common in these months.
October – November: The adults are killed by frost while the cocoons overwinter in the ground.

How To Identify Jumping Worms

Up close view of a jumping worm Photo credit: Nancy Knauss

At first glance, these worms look like other worms. But there are differences you can use to spot them. As the name suggests, these worms squirm and move quickly if disturbed. And when they move, their bodies have an “S” pattern similar to snakes.

Another way to spot them is by looking at the collar-like ring on their body, called clitellum. This smooth ring fully wraps around the body, is cloudy-white, and is found on the upper third of the body toward the head. In contrast, other earthworms have a ring with a more swelled appearance, like a saddle. Also, the ring doesn’t fully wrap around the body of other earthworms.

The soil can also be a clue. As jumping worms eat the organic matter, they leave droppings (castings) that look like coffee grounds and have a spongy texture. While other worms move deep into the soil, jumping worms prefer staying near the soil surface in the top few inches of soil.

If you suspect jumping worms are in the garden, a simple test can confirm your suspicion. To perform this test, mix 1/3 of a cup of ground mustard with a gallon of water in a watering can. Take the water and pour it on top of the soil (this will irritate the adult jumping worms and cause them to rise to the surface). Mustard is great for bringing them to the surface, but it won’t kill them.

Managing Jumping Worms

The best way to remove jumping worms is still unknown, but a few options are available. Currently, research is being done to find chemical treatments for jumping worms. But, there are physical methods that may work.

An established population can’t be fully eradicated but can be managed.

Hand-Picking

Hand-picking can be effective for getting rid of adult worms. Once the worms are removed, seal them in a trash bag. However, this still leaves the worm cocoons in the soil, which are hard to spot.

Solarization

Another option is solarization, which kills the adults and cocoons by heating the soil. Here are the steps for solarization.

Step 1: Find a sheet of clear plastic and place the sheet in a sunny area. Ideally, the sheet will be 10-15 feet long.

Step 2: Take a layer of soil (no more than 6-8” deep), compost, or mulch and spread it on the sheet.

Step 3: Wrap the plastic over the top of your soil and leave it in place for at least 3 days. According to the University of Vermont, the soil can reach over 150°F if the right weather conditions exist. There is variation in the time required to kill the cocoons, but 3 days is a good length if the weather is warm and sunny.

It’s tempting to just lay plastic over the garden, but the soil won’t become warm enough to kill the worms. When the soil warms up, the worms dig deeper and find cooler soil.

Also, if you find jumping worms in your garden, report the sighting to your local Department of Natural Resources or Extension office.

Jumping Worm Prevention

Since these worms are hard to remove, it’s best to keep them out of the garden. Here are tips for preventing them.

Create your own compost. Jumping worms often spread through infected compost that is brought to a garden. Making your own will reduce the risk of worms coming into your garden from somewhere else.
Solarize purchased compost. If you’re buying compost from a supplier, consider using the solar method to treat any worms that may be present. For bagged compost, leave the bags in a warm, sunny area for 3 days.
Inspect plants before moving or sharing them with friends. As you remove the plants, look at the soil and root ball for signs of jumping worms. If something looks off, leave the plants in place.
If you’re a fisherman, don’t release unused bait into the water or woods. Put those worms into the trash.
Inspect plants before purchasing. Whether buying from a garden center or a plant sale, inspect the plant for signs of “coffee-ground” soil.
Wash any pots used for starting transplants.
Never purchase jumping Worms for any reason. Healthy soil will often attract earthworms, but jumping worms are not desirable.
Share information about jumping worms with other gardeners to raise awareness of this invasive worm.

If you find jumping worms in your garden, there’s no need to panic. While our knowledge of these worms is limited, researchers continue to find answers that will lead to more treatment options in the future.

How To Identify & Control Jumping Worms In Your Garden