Jumping Worms

Jumping Worm (Amynthas spp.)

Have you seen an abundance of worms in your garden? If so, look to see if they resemble the worm in the photo. The clitellum or collar goes all the way around the body and is smooth. The worms are very active and have a sheen to them. Look for worm castings around your garden.

The jumping worms alter the structure and chemistry of the soil dramatically, leaving a distinctive grainy soil full of worm castings, and they can damage lawns, landscapes and even the forest understory habitat. People unknowingly spread these worm by using them for bait or transport their egg cocoons on shoes and wheels, in mulch, or via transplanted plants.

Jumping worms reproduce easily. They are asexual (parthenogenetic) and mature in just 60 days, so each year they can have two hatches. The best time to see them is late June and early July. From September until the first hard frost, their population will double and may reach damaging levels.

Research is being done on controlling these worms but nothing has come back with favorable results. What you can try to do is contain their spread by recognizing the worms when you are working in your garden. Don’t transplant mulch, soil or plants to uncontaminated areas. Plant bare root stock or seeds when possible. Do not buy Amynthas worms for composting, vermicomposting, gardening or bait. If you already have these worms, remove and dispose of them by solarizing them or soaking them in isopropyl (rubbing) alcohol. Do not put them in the compost pile or garden.

Photo: Wisconsin Department of Natural Resources

The following resources have been compiled by Cornell Cooperative Extension:

Cornell Cooperative Extension Jumping Worms Fact Sheet

National Park Service U.S. Department of the Interior Species Spotlight

Invasive Earthworms in the Northeast from The University of Vermont, Plant & Soil Science Department

Wisconsin Department of Natural Resources Forest Health Fact Sheet

Jumping Worm: The creepy damaging invasive you don't know from Cool Green Science blog

Jumping Worm Field Guide from Wisconsin

Last updated July 29, 2021