The Riverside Press-Enterprise
Turn the tables on Asian jumping worms
If you follow gardening and agriculture news at all, you have probably heard of Asian jumping worms (aka Giant Asian Jumping Worms). Just when the ruckus over Giant Killer Hornets has calmed, we have another giant invasive pest to worry about!
Asian jumping worms have been found in at least 34 states and have been a problem everywhere they’ve been found. They look like larger versions of the ordinary earthworm, but they have a distinctive white band near one end (I’m not a worm expert, so I can’t tell which end). When disturbed, they will thrash wildly and can jump over a foot. This alone is alarming, especially if you’re using them as fishing bait and they keep escaping.
Ordinary earthworms are pretty mellow creatures. They eat organic matter at a leisurely pace and leave nutrient-rich castings. They tend to hang out in the top foot or two of soil but can burrow to 6 feet in areas subject to cold winters. This burrowing leaves channels in the soil, which aerates and allows water and plant roots to penetrate deeply.
Jumping worms, however, have a voracious appetite and can devour organic matter at an extremely fast pace. When they are introduced into a forest, they can destroy the leaf litter in a short time, leaving tree roots vulnerable and disrupting the ecosystem of the forest floor. When they digest this organic matter, they leave behind their castings (poop), which is remarkably nutrient-poor. These guys are efficient at getting all the nutrients out of leaf litter, which is good for them, but not good for the forest or all the other organisms that live in and feed on leaf litter. They only inhabit the soil surface (since that’s where their food is) and don’t burrow like other earthworms.
Although they are already here in our gardens, we don’t want them in our forests, since that’s where they cause the most damage. As gardeners, there are a few things we can do to prevent this.
Jumping worms can spread quickly by hitchhiking in pots and on plant roots. When possible, buy compost or mulch that has been heat-treated. Heat treatment will kill eggs, weed seeds and dormant insects, so it’s worth the bother.
If you suspect that your garden has been invaded by jumping worms, you can apply a mustard pour (add 1/3 cup of ground yellow mustard to a gallon of water). This will cause the worms to emerge, making them easy to hand pick, but it won’t harm plants or other critters. When picking, place them in a plastic bag, seal it and put in the freezer overnight before discarding. Don’t cut them in half — they can regenerate and you’ll end up with more worms!
Soil solarization can destroy eggs and cocoons as well as some soil-born diseases and weed seeds. Moisten the soil thoroughly, then cover with a clear plastic sheet and weigh it down so it doesn’t blow away. The soil surface will heat up to over 100 degrees, destroying jumping worm eggs. The earthworms will just burrow deep enough, so only the jumping worms will die.