Category: Invasive species

Asian Jumping Worms: Why Your Earthworms Might Be Acting Crazy

On By durhammastergardenersIn earthworm, Invasive species, jumping worm, mulch, mulching and soil chemistry, mulching garden beds, mulching leaves, mulching trees, mulching with arborist wood chips, mulching with cardboard, mulching with paper, over mulching, soil health, Uncategorized

By Marcia Kirinus NC State Extension Master GardenerSM volunteer of Durham County

Asian Jumping Worms – A Growing Threat to Soil Health

Plump juvenile Asian jumping worms in a raised bed. In late spring, early summer you will find all life stages. (Image credit: Marcia Kirinus)

If you’ve noticed unusually active worms in your garden, it could signal a serious problem. These are likely Asian jumping worms, Amynthas spp. or Metaphire spp.. Often referred to as “Crazy Worms” or “Snake Worms,” these invasive earthworms originate from Japan and Korea. They most likely arrived in North America through contaminated soil, compost, or plant material.

According to Matt Bertone of the Insect and Disease Clinic at North Carolina State University, these worms were first recorded in North Carolina in 1978. While they’ve been around for some time, they’ve recently garnered significant attention. One theory is that climate change has boosted their population and more people are gardening.

What sets Asian jumping worms apart from the gentle earthworms we know is their frantic, snake-like wriggling when disturbed—a behavior that earned them their common name.

I first heard about them from a friend and fellow master gardener. She asked if I’d seen them on my property. I had no idea what she was talking about, but I was pretty sure I hadn’t. Living in the city, I assumed this was more of a rural issue, as she lived in a damp, wooded area that seemed ideal for such pests.

One day, while visiting her home, she scooped up a handful of soil, revealing a tangle of Asian jumping worms. “They’re everywhere,” she remarked. At first glance, they appeared to be ordinary earthworms.

“How can you tell the difference?” I asked. She dropped the worms onto her cement driveway, and they immediately began thrashing like small snakes—nothing like the slow, deliberate movements of a regular earthworm. Instead of stretching and shrinking to pull themselves along, they slithered with a serpentine, S-shaped motion. I was fascinated and alarmed.

As I learned how to identify them, I discovered Asian jumping worms in every garden bed on my property—even in my enclosed raised beds suggesting that cocoons came in with the soil, mulch, plant material or on my tools which were not cleaned from using in the native soil. The revelation of these infestations helped explain some of the mysterious plant deaths and soil issues I had noticed in the past.

Why are Asian Jumping Worms Bad?

Asian jumping worms are highly adaptable and can thrive in forests, gardens, and agricultural fields. They reproduce rapidly, out competing other earthworm species. One worm can reproduce without mating through parthenogenesis and produce enough worms to infest an entire garden. Their aggressive behavior disrupts soil ecosystems and plant communities.

Unlike common earthworms, which burrow 1-4 feet below the surface, Asian jumping worms live near the topsoil and consume all organic matter in their path. Mulch, leaf litter, old decaying roots, and leaves are quickly devoured, leaving soil depleted and structurally compromised.

In their wake, they leave behind grainy, coffee-ground-like soil that lacks essential nutrients and structure. This degraded soil erodes easily, struggles to retain moisture, and makes it difficult for plants to establish roots—especially those with shallow root systems.

Asian jumping worms are an annual species; the adults die after the first freeze. However, their cocoons/eggs which are about the size of a mustard seed, survive the winter and hatch when temperatures consistently reach 50°F. The cocoons are dirt-colored and nearly impossible to spot. They can spread easily through potted plants, landscaping equipment, mulch, tire treads, your shoes or even your dog’s paws. 

How to distinguish an Asian Jumping Worm from a Common Earthworm

Asian jumping worms can be distinguished from common European earthworms (like nightcrawlers) by several features:

  • Behavior:
    • Jumping worms thrash violently and move like a snake when handled. Their tails easily break off, much like a lizard shedding its tail when grabbed.
  • Appearance:
    • The adults are the easiest to identify because they are smooth, glossy, dark brown to gray body with a prominent, white, ring-like band (clitellum or reproductive band) encircling their body. The clitellum is located closer to the head than in the common earthworm and is flush with the body, not raised. The younger worms do not have a prominent clitellum so use other distinguishing factors such as behavior, location and color to identify them.
  • Location:
    • Found in the top layer of soil or leaf litter; they do not dig deep tunnels.
  • Castings:
    • Soil in areas with jumping worms looks like loose, dry coffee grounds.
Note the visual differences from the more common earthworm above and the invasive Asian Jumping Worm below. (Image credit: Brunswick-Topsham Land Trust)

Left: Asian Jumping worm, Amynthas spp. cocoon/egg at yellow arrow, on soil surface. Note granular soil texture all around egg due to worm castings. (Image credit: Marie Johnston, courtesy of the University of Wisconsin-Madison Arboretum) Right: The light-colored clitellum, or reproductive band around the adult Jumping Worm, wraps completely around its body and is not raised as in the common earthworm. (Image credit: University of Illinois Extension, Technical Forestry Bulletin NRES-1603)

What should I do if I Find Asian Jumping Worms in my Garden?

  • Prevention is key:
    • Currently there are no great curative management options available for home gardeners with existing jumping worm infestations. Therefore, prevention is your best line of defense. Some preventative measures are:
      • Keep tools clean. Do not use tools from an infested spot in an uninfected spot without disinfecting in between.
      • Buy compost, mulch, soil from reputable places. Before you buy, ask what measures are taken to avoid Asian jumping worms.
      • When purchasing plants, buy from reputable sources and carefully inspect the root ball. If you suspect contamination, consider cleaning all soil off new plants. Purchasing bare-rooted plants is another option.
  • Inspect and Monitor:
    • Regularly check your garden and compost for signs of jumping worms. If you have them, hand pick and destroy them when you find them. Seal them in a plastic bag and throw them in the trash. Alternatively, use a bucket of soapy water to drown them in and then dispose of them. Avoid using a dry bucket, as they can easily climb out of a five gallon bucket without problem. By hand picking, you are reducing the adult population which will eventually decrease the number of egg-carrying cocoons in the landscape.
  • Predators:
    • Encourage more wildlife. According to a social media group I belong to on Asian jumping worms, many birds such as Robins, Bluejays, Grackles, Turkeys, Chickens eat the worms. Earth snakes, moles, and mice have also been reported to eat them.
  • Heat Treatment:
    • Jumping worms and their cocoons are sensitive to high temperatures. The University of Wisconsin – Madison conducted research which shows that neither worms nor cocoons can survive at 104°F or higher for over three days. Compost piles, under appropriate conditions, can reach this temperature.
  • Share Information:
    • Share your knowledge, experiences, successes, and failures with fellow gardeners. Raising awareness and sharing information can help combat the spread of these invasive worms.
  • Prevent Spread:
    • Avoid moving soil, mulch, or plants from infested areas.

We encourage you to share this post with others to help educate our community

Resources and Additional Information

Achieving Peak Tomato Performance

On By durhammastergardenersIn edibles, fertilizer, garden irrigation, Garden pests, gardening irrigation, ground covers, growing media, innovative watering, Invasive species, plant disease, plant fungi, proper irrigation, sustainable gardening, sustainable watering
A bounty of beautiful tomatoes. (Image credit: Kathryn Hamilton)

By Kathryn Hamilton, NC State Extension Master GardenerSM volunteer of Durham County

This summer, Durham County is one of eight counties in North Carolina to participate in a state-wide tomato trial. We will compare yields of three tomatoes created by NC State against ‘Cherokee Purple’ regarded for its flavor, productivity, and resistance to cracking. Check out our page on the blog called “Tomatoes on Trial” The 2024 Tomato project here. While we are busy conducting the trials, here are some tips to help you maximize your harvest.

Water Carefully and Consistently

Cracking occurs when tomatoes get a huge amount of water all at once (as an example, after a major storm) causing the fruit to swell and the skin, because it cannot grow fast enough, to crack. Calcium travels from the soil through water, and if water is insufficient the calcium never reaches the fruit, resulting in blossom end rot. This condition usually affects the first tomatoes and can be reversed with regular watering.

(Left to right) Cracking often occurs after a heavy rain. The skin can’t keep up with the swelling of pulp and consequently splits. (Image credit: Mary Knierim) Blossom end rot is preventable by consistent watering which brings calcium up into the fruit. (Image credit: NCSU Plant Disease and Insect Clinic)

During the growing season, tomatoes need 1 – 2” of water per week, the equivalent of two to four gallons. One way to measure this is to time how long it takes to fill a two-gallon container, then count along each time you water. To reduce the incidence of soil-borne diseases splashing on to the tomato vine, water at soil level, preferably in the morning to allow any leaves to dry out during the day. It is best to water deeply once or twice a week to encourage root development. The soil should be damp 6 – 8” down. Use a water meter, a trowel, or your finger to get a “reading.”

Mulch Your Bed, or at Least your Plants

Mulching carries multiple benefits. It keeps the soil moist and can help reduce both weeds and the spread of soil-borne diseases. Organic options include dried grass clippings, which have not been treated with an herbicide, and shredded cardboard or newspaper. Other options include hay or straw, and leaves (provided they are not from the black walnut tree). Avoid sawdust and wood chips which will draw nitrogen out of the soil as they decompose. There are pros and cons regarding plastic mulches. Black can heat up the soil too much; clear can foster the growth of weeds. Research at Clemson University has shown that red mulch (now available in small quantities at some on-line garden retailers) can boost tomato yields by 20 percent while conserving water and controlling weeds.

(Left to right) Grass, untreated with herbicide, is an excellent mulch; Red plastic mulch developed by Clemson University and the US Department of Agriculture is now available in smaller quantities from some on-line retailers. Use it to increase yields, prevent weeds, and retain moisture. This is not to be confused with red-dyed wood mulch. (Image credits: Kathryn Hamilton)

Feed Wisely

A three-number code on each bag of fertilizer identifies its composition. The first number relates to nitrogen (think greenery); the second to phosphorous (flowers and fruit formation), and the third, potassium (contributing strong stems and disease resistance). Once the plant has started to set fruit (usually 4 to 6 weeks after planting) side dress the tomatoes with a balanced fertilizer (i.e. 8-8-8), or one in which the first number is smaller than the others. An over-abundance of nitrogen will promote vine growth at the expense of fruit. Among the best analyses for tomatoes, according to the University of Missouri are 8-32-16 and 6-24-2. Follow package directions in terms of fertilizer amount and frequency.

Practice Rigorous Maintenance

To reduce contamination by soil-borne diseases, prune the bottom leaves up by as much as a foot. Be rigorous in removing diseased and rotting leaves.

Pruning leaves up to 18″ from the ground reduces transmission of soil-borne diseases. (Image credit: Kathryn Hamilton)
Diatomaceous Earth

Diatomaceous earth is a highly porous powder made from the sediment of fossilized algae. Sprinkled at the base of the plant and on the leaves and fruit it can help control a variety of insects. Diatomaceous earth is not a poison; it causes insects to dry out and die by absorbing the oils and fats from their exoskeleton. To be effective it must remain dry and undisturbed. The Food and Drug Administration lists diatomaceous earth as “generally recognized as safe.” Food-grade diatomaceous products are “purified.” It is generally available in garden centers, and sometimes even at stores such as Walmart.

Dusting fruit, plant, and earth with diatomaceous earth significantly reduced predation from pests such as these Rollie Pollies. (Image credit: Kathryn Hamilton)
Fungicides

Fungicides can be helpful as both a protectant and preventative against fungal disease. Fungicides labeled for use on tomatoes and containing either chlorothalonil or mancozeb can reduce the spread of fungal leaf diseases. Copper-containing fungicides protect plants from leaf diseases caused by bacteria and some fungi. Preventative activity occurs when a fungicide is present on or in the plant before the pathogen (disease) arrives or begins to develop. Preventative fungicides can still be used if the disease is present at low levels, since they will prevent new infections from occurring on the unaffected leaf tissue. A curative situation occurs when the fungicide stops the early growth of the pathogen. But, it must be applied within 24 to 72 hours of the infection. Fruit treated with some fungicides can be eaten immediately; other fungicides require a waiting period. As with any chemicals, read the label carefully before use.

Prune for Air and Yield

In terms of yield, pruning suckers is a choice. Cutting them out will yield fewer but bigger tomatoes. Leaving them in will increase quantity. However, pruning suckers will help to increase air flow and potentially decrease air-borne disease. This can be particularly helpful if, like most tomato fans, you over-plant your garden bed.

Suckers sprout from where the stem and branch of a tomato meet. Bonus: they will root in water to produce a new tomato plant (Image credit: Kathryn Hamilton)

Growing tomatoes can be both challenging and rewarding. To help with the challenging issues, please find additional information in the following links.

Resources and Additional Information

Learn more about organic and inorganic mulch as well as cover crops to optimize tomato growth. Mulches for the Home Vegetable Garden (UVA) https://www.pubs.ext.vt.edu/content/dam/pubs_ext_vt_edu/426/426-326/SPES-256.pdf

This article covers tips for the home gardener and summarizes common problems related to growing tomatoes. How to Grow Tomatoes in your Garden (Utah State)
https://extension.usu.edu/yardandgarden/research/tomatoes-in-the-garden

A nice review of the disease cycle and when to use preventive or curative fungicides.
Preventive vs Curative Fungicides (Iowa State) https://crops.extension.iastate.edu/cropnews/2008/07/preventative-vs-curative-fungicides

This resource provides an overview of how to diagnose tomato diseases and treatment options. A Valuable Resource on Tomato Diseases (NCSU)

https://vegetables.ces.ncsu.edu/tomatoes-diseases/

Article Short Link: https://wp.me/p2nIr1-4BD