Mulch could be one of the major ways that jumping worms are being spread. If you buy mulch in the spring, remember that you won’t know if it has jumping worms until later that summer as they develop from cocoons to adult worms. Consider covering your mulch pile with clear plastic to solarize and kill the worms and their cocoons at temperatures above 104 degrees for at least 3 days.
Timothy McCay, a professor of Biology and Environmental Studies at Colgate University, recently spoke to the Hamilton Garden club about jumping worms. We are used to seeing earthworms from Europe. Jumping worms are from Asia and are causing problems because they rapidly eat their way through organic matter. In the forest, they consume the duff layer on top of the soil which the seedlings and wildflowers need to grow. In our gardens, they eat through organic matter and leave behind their casts(pooh). When soil becomes filled with their casts it becomes grainy and dry and plants have a hard time rooting successfully.
Jumping worms reproduce quickly. They do not need a mate to produce over 60 cocoons per year. They die every winter but their young survive inside resilient cocoons. In the spring when the weather warms above 40 degrees the jumping worms emerge from their cocoons. When they have reached maturity in the summer they will start to reproduce. In November they die off.
Because the worms don’t emerge from their cocoons until later in the spring, knowing if they are present has to wait until mid-summer. This creates a problem for our garden clubs who dig up plants to sell. After talking with Professor McCay, it seems that a good precaution is if you know that you have jumping worms do not share your plants. If you aren’t sure if you have jumping worms a solution might be to rinse away all soil from your plant’s roots and repot in potting soil. Some clubs are canceling their plant sales because so many members have jumping worms. The best solution is to be informed and use common sense.
To determine if you have jumping worms, they thrash around like a snake when threatened. Their clitellum (the narrow band around their body) goes all the way around them. On the European earthworms, the clitellum only goes partway around their body. Their clitellum in smooth as compared to being raised on the European worms. Do a mustard pour test: Mix a gallon of water with 1/3 cup of ground yellow mustard seed and pour slowly into the soil. This will drive many worms to the surface. If you have jumping worms report it and avoid moving plants or soil from your yard.
For more information about jumping worms: http://cceonondaga.org/environment/invasive-nuisance-species/jumping-worm