Jumping worms are native to Asia, but have been creeping into America since the late 1800s.
We wrote about them last year: Asian jumping worms. I’ll refresh your memory, it’s a crawling invasive species that moves – jumps? – Across the Midwest.
The worm may be famous for the swatting behavior that led to its name, but it is notorious for its impact on land and soil. Unlike more common worms, jumping worm castings do not return nutrients from organic matter to the soil. Rather, it binds nutrients and looks a lot like ground coffee: small, dry, and crumbly.
We know all this, so why write about them again?
The problem is that it’s expanding, according to Brooke Alford, an urban agriculture educator at Purdue University, and humans are largely to blame. This comes as we enter the fall planting season and people are dividing and donating plants.
In this edition of Scrub Hub, we ask: How do jumping worms spread and what can you do to help slow the expansion?
Short answer: Humans help spread
As of July 2022, the Purdue Plant and Pet Animal Diagnostic Laboratory has confirmed the presence of jumping worms in Bartholomew, Vanderburgh, and Allen counties. A year later, worms were also reported in Monroe, Brown, LaPorte, Vincennes and Jasper counties.
The problem may be more widespread, but it’s difficult to determine because the worms aren’t reported as often because Hoosiers aren’t aware of them, Alford said. They can be difficult to distinguish from the typical European earthworms we know in Indiana, which are also non-native species but are beneficial to the environment.
However, there are ways to differentiate between them.
Rubbing center: What are jumping worms? Are they destroying my garden? (they might be)
Concerns have only magnified in the past month. In preparation for the donation and sale to the Bloomington plant, they found jumping worms, Alford said. That has sparked a conversation about imposing a ban on plant sales, an approach taken in some other areas of the Midwest.
“We don’t want to stop plant sales, they are very important for preserving the local environment,” she said. “But we need to do it as safely as possible.”
For now, officials are focusing on implementing best practices to help slow the spread of the disease.
Long answer: How do we help slow things down
The fall and spring planting seasons are some of the biggest opportunities for Hoosiers to unintentionally spread these worms. If someone divides plants in their yard to give to a neighbor or donates plants to a sale, jumping worms may be a hit.
This can happen even with plants from established nurseries, Alford said. So, regardless of where you’re getting your plants, or if you’re planning to donate some, there are steps you can take.
Alford recommends doing what’s called bare rooting when dividing or donating plants. This means removing all the dirt from the roots. Start by shaking it and then stir it in some water to remove any remaining soil that may contain jumping worms.
It is also important to clean any vessels using a pressure washer or a good scrub. While jumping worms can’t survive Indiana winters, their eggs can, Alford said. They are microscopic—the size of soil particles—but can sometimes be seen on the bottoms of pots.
The next step is to place the plants in sterile soil. The easiest way is to buy bags of sterilized potting soil at the store and keep them in the car for a few days, Alford said. This should heat it to a temperature that kills any unwanted organisms.
Alford recommends people follow the same procedure when they bring new plants home. While it’s difficult to throw away what appears to be perfectly good soil for planting, she said it’s best to be careful.
“It’s about taking those extra steps so we can know what we’re up against,” Alford said.
Because jumping worms are spread only by humans, only humans can slow their spread, Alford said.
Purdue is hosting a virtual lunch-and-learn event on Sept. 22 about jumping worms. The event is free, but requires registration.
If you see a jumping worm, Purdue recommends taking a photo and reporting it to the GLEDN mobile app, EDDMapS, or the Invasive Species Line at 1-866-663-9684 or to depp@dnr.IN.gov.
Also, if you are not sure if you have jumping worms, do not hesitate to send a sample to the Bordeaux Plant and Pest Diagnostic Laboratory.
If you have more questions about worms, other insects, or any other topics, let us know! You can submit questions through our Google form below. Can’t see the form? click here.
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IndyStar’s environmental reporting project is made possible through the generous support of the non-profit Nina Mason Pulliam Charitable Foundation.