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They thrash about and are here for your soil

BLOOMINGTON, Ill. — They are here! They thrash side to side when threatened or touched by the unknowing observer.

Jumping worms have spread throughout our Central Illinois gardens and they could be in your backyard right now. Local Master Gardeners have confirmed non-native and invasive jumping worms in Bloomington-Normal gardens. During the recent Glorious Garden Festival, Master Gardeners handed out over 400 flyers educating local garden enthusiast on how to halt the spread in Central Illinois. As of July, 30 counties in Illinois have confirmed jumping worm. 

What makes these worms so bad?

Gardeners of Central Illinois may have already had their encounters with jumping worms while working in the garden, not immediately noticing the differences. Populations of jumping worms have the potential to change the soil structure, deplete available nutrients, damage plant roots, and alter water holding capacity of the soil.

Many gardeners may consider earthworms beneficial to garden soil. However, jumping worms break down organic matter (leaves, stems, and mulch) so quickly that their waste (castings) are added at a rapid rate, and could greatly transform our soil. They do not tunnel in the ground like other earthworms, they move through the top 2-4 inches of the leaf litter and topsoil, devour it and leave behind their castings that look like coffee grounds.

Chris Evans, forestry specialist for University of Illinois Extension says, “As the worm feeds, they alter the soil structure by increasing the aggregate size, creating larger clumps of soil with more space in between them. This causes their castings (excrement) to make up a higher percentage of the soil. This coffee ground look may only appear when populations are high and there is high organic matter in the soil. Soils with lots of clay may not form this telltale soil signature.

Horticulture Educator, Chris Enroth, says jumping worm is new to Illinois and has not been studied for very long so there are quite a few unknowns. Here are a few things that have been researched or observed:

  • They can survive almost exclusively on cellulose, allowing them to persist on mulch alone. 
  • It is believed that adult worms cannot survive our winters, but their eggs can. Eggs are in cocoons left behind to overwinter. Eggs and young worms can be transported on tools, soil, and mulch, and moved on divided garden plants in cocoons. Evans says “some adults are actually making it through the Illinois winters. They usually are in protected locations.” 
  • Preliminary study in Wisconsin shows that when jumping worm arrives in a forest setting, they displace other earthworms until jumping worm is all that is left.
  • Jumping worm has the potential to be very destructive in both home landscapes (gardens and lawns) and natural areas. Jumping worms can reduce litter mass on the forest floor at a rapidly accelerated rate. 
  • Jumping worms can affect wildlife interactions with soil by drastically altering their environment, reducing habitat and food sources may be reduced.

Identifying the invasive jumping worm

Jumping worm can be confused with normal garden worms. However, they tend to have very glossy skin. Jumping worm as its name implies will jump, squirm, and flip when disturbed. Their movement can almost appear snake-like as they thrash in an S-shaped manner.

Another characteristic is the jumping worm’s top and bottom are different colors. As they squirm and jump you will see the opposing flashes of color.

Jumping worms also have a smooth, milky white clitellum (colored band) that completely circles the body and is not raised. In night crawlers, the clitellum sits more like a saddle and is raised above the worm’s body. Local University of Illinois Extension Horticulture Educator, Kelly Allsup, says, “The whiteness of the band varied between worms and faded, but the band was always flat and located on the 14th or 15th segment from the head vs. 23rd through 32nd segment of a normal garden earthworm.” 

They may also drop their tail as a defense mechanism. 

Jumping Worm on Table
Identifying a Jumping Worm (Illinois Plant Clinic)


  • Investigate your yard or garden using a third cup dry mustard powder with a gallon of water. Remove leaf layer to get to soil surface and pour the solution into a small area. All worms will come to the surface within a few minutes. This practice will not hurt plants or the worms but will allow you to identify them. 
  • Clean hiking boots, landscape equipment, and garden tools to prevent transfer of cocoons filled with winter- hardy eggs. Boot brush stations and alcohol or bleach solution can be used to clean tools. 
  • Buy compost or mulch that has been adequately heated to reduce the spread of viable eggs. Most commercial compost products have been pasteurized above the 104-degree temperature needed to kill eggs. 
  • Do not transfer soils or plants from garden to garden. 


Remove any adult worm found, place them in a plastic bag, leave them in the sun. There are currently no approved methods for chemical or biological control; cultural control strategies such as prevention and slow the spread is our goal at this early stage.


Extension’s presentation reviews what we know about jumping worms, their potential impacts to natural ecosystems and managed landscapes, and what can and should be done about them. View the video by Presenter, Chris Evans, Extension Forestry and Research Specialist with the University of Illinois. He specializes in invasive species and forest health issues.  If you want to skip to the part of identifying these jumping worms start at 14:15 in the video. University of Illinois Extension also wishes to provide Jumping Worm Fact Sheet here or printed at your local Extension office.

Extension will be holding a free, local discussion session on this topic from 3 to 4 p.m. on Tuesday, August 31 at the McLean County Extension Office in Bloomington. No cost to attend but please register to RSVP to this event. For additional questions, please contact the Extension office at 309-663-8306. If you will need an accommodation in order to participate, please contact us. Early requests are strongly encouraged to allow sufficient time to meet your access needs.

WRITER: Kelly Allsup, Horticulture Educator, Serving Livingston, McLean & Woodford Counties
SOURCE: Kelly Allsup, Horticulture Educator; Chris Enroth, Illinois Extension Horticulture Educator; Chris Evans, Illinois Extension Forester

ABOUT EXTENSION: Illinois Extension leads public outreach for University of Illinois by translating research into action plans that allow Illinois families, businesses, and community leaders to solve problems, make informed decisions, and adapt to changes and opportunities.