Hi Linda,

Thank you for contacting the UNH Extension Yard and Garden Infoline with your question about jumping worms.  I have included below the current standard reply prepared by UNH Extension staff for this issue.  According to this information, "Purchase bare root plants or rinse newly acquired potted plants in a separate disposal container to remove potential cocoons." 

Jumping worms are invasive earthworms that are established in New Hampshire and throughout much of the Northeast.

Please see below for jumping worms identification and our current management recommendations:

Jumping worm ID 

Jumping worms are brown to grayish in color with a smooth, white band (clitellum) that completely encircles the body near the head. Additionally, this band is typically closer to the head on jumping worms vs. European nightcrawlers, which have a red/pinkish clitellum that is more rounded and does not go all the way around the body. Although it can be difficult to identify jumping worms by sight alone, their behavior is distinctive. Jumping worms tend to have firm bodies and writhe powerfully if you try to pick them up. They will occasionally lose their tails as a defense mechanism to escape predators. Jumping worms are also remarkably fast, moving in an almost snake-like fashion across the soil surface. 

Ecology and Management

It is possible for gardens and home landscapes that have been invaded by jumping worms to continue being productive despite their presence, although preventing their spread is key. Jumping worms typically live in the upper 4 inches of the soil surface, consuming leaf litter and other organic matter. If a large population of jumping worms is present, they can actually start to change the structure of the soil, giving it a coffee grounds-like texture from their castings. If enough of the soil around your plants is converted to these castings (in the garden or in containers), plants may start to suffer from water and nutrient deficiencies, and soil will eventually need to be replaced.

In forest ecosystems, undisturbed soils and decomposing leaf litter are important for native plant seed germination and survival. When jumping worms become established in the forest, native plant populations tend to decline, and invasive plants become more prevalent. 

Unfortunately, there are currently no approved chemical methods for controlling jumping worms once they are in the landscape.  

While there are pesticide and fertilizer products that have been shown to kill earthworms as well, they are not labeled for this exact use. 

Any pesticide should be applied following the label directions, and caution should be used when applying fertilizer and soil amendments, particularly regarding application rates and proximity to water sources (some of these products can be harmful to aquatic life.)

Hand-picking jumping worms from the garden is unlikely to get rid of them entirely, but it can reduce the population in localized areas. A jar of soapy water or diluted vinegar is sufficient for killing them.

Some other gardeners have had limited success with setting up confined "traps" of piles or lidded buckets with holes drilled at the bottom containing leaf litter/compost in areas away from their gardens, with the goal of concentrating jumping worm populations to these piles to facilitate mass manual removal/elimination. Besides the adults, jumping worm cocoons (which encase the eggs) are more of a concern for increasing the population in your garden area, as they are very difficult to see (about the size of a poppy seed), and can lie dormant for two years. Jumping worms lay these cocoons from late summer through fall, which overwinter and hatch in the late spring/early summer.

Research has shown that when material is heated to a temperature of 104 degrees F or higher for 3 days, this kills all life stages of the worm including the cocoons. This can be achieved by solarizing soil and soil amendments (mulch and compost); this technique involves layering the material between two sheets of clear plastic (clear plastic retains more heat in the material than black) enclosed like a package, which will allow the most heat to collect, and will ensure that any worms cannot escape from the bottom. Solarization can most easily be achieved on bright, sunny days with moist material; placing on asphalt can help to raise the temperature faster as well.

Bagged compost and mulch have also been known to contain jumping worms, and it is recommended to place on an impervious surface (driveway or patio) for a day or so in the full sun to heat up as a precaution. 

While it may be challenging to eliminate jumping worms in your landscape, you can still play an important part in preventing their spread - Do not share compost, mulch, topsoil, or plants with other gardeners if you have jumping worms on your property. Purchase bare root plants or rinse newly acquired potted plants in a separate disposal container to remove potential cocoons. 

Additional resources 

UNH Extension - Plant Sales and Jumping Worms https://extension.unh.edu/resource/plant-sales-and-jumping-worms 

Univ. of Maryland - https://extension.umd.edu/resource/invasive-jumping-worms/ - this resource also includes how to use a mustard solution to check the presence of, type, and quantity of earthworms in a given area (will draw out jumping worms and common earthworms as well), and treatment for purchased compost, mulch, and soil to kill any potential worms or eggs present in the material. 

 Cornell -https://ccecolumbiagreene.org/resources/jumping-worm-fact-sheet  

https://portal.ct.gov/-/media/CAES/DOCUMENTS/Publications/Fact_Sheets/Entomology/Jumping-worms-in-Connecticut.pdf Jumping Worms (Megascolecidae: Pheretima) in Connecticut - excellent resource for FAQs 

UMass Amherst - https://www.umass.edu/agriculture-food-environment/landscape/fact-sheets/invasive-jumping-worm-frequently-asked-questions  - excellent resource for FAQs