Colorado agriculture officials are sounding the alarm for gardeners and landscapers to keep an eye out for the invasive Asian jumping worm, better known as the "crazy worm," after recent confirmations in the region. The species is notorious for violently thrashing when disturbed and for chewing through leaf litter so quickly that it leaves behind a granular, coffee-ground-like layer that dries out and weakens soil, exposing plant roots and making gardens tougher to maintain.
State authorities issued an invasive-pest alert this week after a confirmed detection in Denver’s Hilltop neighborhood in October 2025 and reports from other states, including Oklahoma, according to KFOR. The Colorado Department of Agriculture told reporters there are currently "no effective eradication methods" for the worms and urged residents to report any suspected infestations.
Why gardeners should care
Researchers say jumping worms can rip through leaf litter at high speed and leave behind castings that alter soil chemistry, cutting down porosity and water retention, and making soils much harder to re-wet. As the Oregon State University Extension Service notes, the worms' castings "quickly dry into hard granules that are difficult to rewet," which can stunt plant growth and open the door for invasive plants to move into newly exposed patches of ground.
Where it's been spotted
Mapping efforts and state reports show jumping worms have turned up across much of the United States, from the Northeast and Midwest to the West Coast, in a scattered pattern of local outbreaks that experts believe is still under-reported. The USDA's National Invasive Species Information Center offers background material along with links to mapping tools, while the Early Detection & Distribution Mapping System (EDDMapS) compiles point records submitted by agencies and members of the public.
How to avoid spreading it
With no reliable way to wipe out established populations, prevention is the main line of defense. Officials advise avoiding the movement of soil, mulch, compost, or potted plants if you suspect an infestation, checking root balls carefully and considering bareroot plants instead, and never using jumping worms for bait or vermicomposting. The Cornell Cooperative Extension recommends confirming that bulk mulch or compost has been heat-treated to at least 130°F for three days to destroy cocoons, or opting for bagged, treated products.
How to check and report
Key identification clues include a smooth, milky-white clitellum that completely encircles the body, the worms' signature erratic thrashing when disturbed, and a distinct coffee-ground layer of castings on the soil surface. Colorado residents are being asked to report suspected infestations to the Colorado Department of Agriculture's jumping worm reporting form, according to KFOR, and anyone can upload sightings and photos to databases like EDDMapS to help track the spread.
Because there are no reliable eradication methods once jumping worms are established, officials and researchers stress that the most effective strategy is preventing new introductions and catching new arrivals early, as the Cornell Cooperative Extension points out. State extension offices and federal resources provide identification guides and step-by-step advice for gardeners who suspect infestations, and experts urge residents to report even small finds to help slow the worm's spread.
