Casual plant sales and plant swaps can sometimes pass along more than a good plant: They can also pass along invasive species traveling along in the soil of the plant.
A current concern is the invasive jumping worm (Amynthas species) being reported in the Pacific Northwest, and most recently in the Willamette Valley. Sent to OSU’s online Ask Extension service, an inquisitive gardener found a worm that seemed “very energetic.” A video of jumping worms in a container helps to show why they received their "energetic" common name.
Why are jumping worms a concern for gardeners?
Jumping worms have a negative impact on soil structure. Their feeding creates a more porous soil (water moves through quickly) reducing moisture content. Jumping worms also easily spread to new garden areas by hitchhiking in contaminated soil and compost.
How to tell the difference between jumping worms, earthworms and red wigglers (composting worms)?
- Noticeably thrash and jump when disturbed.
- Have a smooth milky-colored band called the clitellum where eggs (cocoons) are released from.
- Have an incredibly large mouth that enables the worm to excavate, scoop and sort organic debris (akin to a mechanical excavator) for consumption. See a video displaying the large mouth.
View illustrations comparing jumping worm, European nightcrawler and the common earthworm in Sea Grant Extension's helpful guide to identifying jumping worms. If you need help identifying jumping worms, share photos or videos with Master Gardener volunteers in your county.
How are jumping worms spreading in Oregon?
Jumping worms produce light-colored and rounded cocoons (eggs). Cocoons are extremely small (2–3 millimeters/.07 inches in diameter) and difficult to pick out from the surrounding soil. Worms and cocoons spread by:
- Movement of contaminated soils.
- Movement of mulch.
- Poorly made compost.
- Sharing plants.
- Sharing gear.
- Gear contaminated with jumping worm cocoons (eggs).
We have received recent reports from gardens in McMinnville, Pendleton, Salem, Eugene, Corvallis, Clackamas and possibly Roseburg.
What can gardeners do to prevent the spread of invasive species like jumping worm?
If you are attending plant sales or plant swaps, ask questions:
- Have you observed earthworms that jump or move in thrashing, snake-like movements in areas where the plants were grown?
- Were the plants dug or propagated in soils from members’ yards?
- If so, what plant sanitation steps were taken?
If you are digging and moving plants:
- Do not share plants, soils and mulches with known pests and diseases.
- Clean and dry tools and footwear.
- Carefully, remove excess soil around roots. Inspect plant divisions for jumping worms. Root washes can help you find and remove jumping worms, as well as cocoons (eggs).
- Plant divisions in clean potting mix.
- Help plant recipients to be on the lookout for jumping worms to prevent introductions into their gardens.
Become knowledgeable about jumping worms
- Share this information with other gardeners.
- Practice and promote good plant sanitation practices in plant sales and plant swaps.
I found jumping worms in my garden, now what?
- Report sightings of jumping worm in Oregon.
- Management options are limited; prevention is KEY!
- There are no pesticides available to treat jumping worms.
- Researchers are studying how to control these worms but nothing has come back with favorable results.
- Containing their spread is the best thing you can do! Learn to recognize the worms.
- Do not transplant mulch, soil or plants without careful inspection to ensure that you are not spreading jumping worms.
If you do find jumping worms:
- Dispose of jumping worms in the trash and not in compost or yard waste bins.
- You may consider solarizing soil where jumping worms have been seen. Some researchers think this may help to kill jumping worms and cocoons in the soil.
Even well-intentioned “plant rescues” of native camas or Oregon iris need to follow these basic plant sanitation methods to help prevent the spread of jumping worm.