An aggressive Asian earthworm is negatively impacting gardens and the ecosystem.

Asian jumping worms are a relatively new invasive species in the United States. They can be found in the Southeast, along the Eastern Seaboard, and in Mid-Atlantic, Midwest, and some Northwestern states.

These invasive worms live in the organic matter or the topmost layer of soil. Asian jumping worms are ravenous feeders, and they quickly consume the organic matter and degrade the soil.

Asian jumping worms are an annual species. The adults die after the first freeze. The cocoons, which are about the size of a mustard seed, will survive the winter and hatch in mid-April after temperatures reach 50 degrees for a consistent period.

One telltale sign of an infestation is a very uniform, granular soil created from worm castings, a nutrient-rich soil that the worms leave behind. The texture of the soil is often compared to coffee grounds.

When you scratch the top layer of soil, you will see the worms thrashing about with an erratic, snakelike movement. These worms can reach six-inches in length and are very active.

It is difficult to remove an invasive species once it is well-established in an ecosystem. The focus must be on preventing their spread. The cocoons, which are very small and difficult to see, can be easily introduced into your garden in compost, bark and leaf mulch or when swapping plants with friends.

Consider reducing the amount of organic matter you add to your garden each year. Most importantly, when purchasing bulk mulch or compost, use a reputable producer that has heat-treated the material to a temperature of 130 degrees for at least three days to destroy the cocoons. The other option is to purchase bagged mulch.

Check plants that you bring into your garden for the distinctive coffee-ground-like soil. If present, throw out the plant or remove all soil and rinse the roots thoroughly before bringing the plant into your garden. If you have a small population, handpick and destroy adult worms by bagging them and throwing them in the trash.

Research is ongoing. Abrasive materials such as ground up charcoal and diatomaceous earth may show some promise in killing adult jumping worms. Incorporate one of these products into the infested soil to a depth where the worms are located. Worms that come in contact with the materials will be adversely affected.

It is important to destroy Asian jumping worm cocoons. The cocoons are sensitive to heat and can be destroyed with clear plastic solarization. In late spring or summer, cover moistened soil with a sheet of transparent polyethylene for two to three weeks or until the soil temperature exceeds 104 degrees for at least three days.

Diligence in following preventive measures and implementing control methods for the cocoons and adult worms can impact the health of your soil by eliminating these destructive invasive worms.

Flower facts:

The rose is an example of a “solitary flower,” which has a single flower on a single stem. The globe thistle has a cluster of flowers arranged on a stem, which is an example of an “inflorescence.”

Flower shape and the type of inflorescence are important characteristics when identifying unfamiliar plants and sometimes indicate the type of pollinator the plant will attract.

To maximize the effectiveness of your pollinator habitat, plan to have a variety of plants in bloom throughout the season. Overlapping bloom times will ensure there are always flowers in your garden to provide nutrition for pollinators.

Chemical treatments:

If using a chemical treatment for insect pests of vegetables, protect pollinators by spraying during a time of day when bees and butterflies are least active and only during dry, still weather.

“Growing Green” is contributed by Lehigh County Extension Office Staff and Master Gardeners. Information: Lehigh County Extension Office, 610-391-9840; Northampton County Extension Office, 610-813-6613.