Earthworms in your garden can do some amazing things, but not all worms are good guys, and even the good guys may cause trouble! Learning what earthworms look like and where they
belong can help your garden grow.
What good are worms?
Earthworms are great decomposers—they tunnel through garden soil, eating and breaking down a lot of dead leaves, tiny plant roots, and the fungi and microbes that grow on them. Their
tunnels let air, water, and many important nutrients move through the soil to help keep plants healthy and create the moist places that keep worms happy.
Good guys and bad guys
Earthworms in your garden are usually good, but there are a lot of different kinds of worms! Most worms came to Western North Carolina from other parts of the world. We call these worms
non-native or exotic and some can cause damage.
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An invasive Asian jumping worm is seen at the bottom next to a common nightcrawler. Earthworms: There are both native and non-native earthworms, but even our common
nightcrawlers (Lumbricus terrestris) came here from Europe!- Earthworms that help your garden are not as welcome near streams—where the nutrients they bring can cause pollution—or in forests—where they might break down too much of the leaf litter that forest plants and animals need!
- Non-native jumping worms (Amynthas agrestis) do serious damage because they live closer to the soil surface and eat a lot of leaf litter and mulch. They don’t help get nutrients into the soil like other earthworms and can take over because they grow and multiply faster. Called jumping worms because they may jump or move very fast, they also look different from other earthworms.
- Hammerhead worms (Bipalium spp.) and terrestrial flatworms are other non-native worms that may do damage. Because they especially like eating earthworms (as well as snails, slugs, and other small insects), they can decrease the number of “good” earthworms that are better for your garden. These critters look very different from earthworms!
Close up of the head and neck region of a flathead worm, Bipalium Kewense. Note the broken collar around the neck. 
Terrestrial flatworm, Microplana terrestris from North Carolina.
What can you do?
How do you keep the good earthworms happy and keep the non-native worms of all types out of your garden?
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Cocoons of jumping worms. The most important thing to do is check the soil of all plants you buy—or get from friends—to make sure there aren’t any unwanted worms or cocoons in the soil. Cocoons are extremely small and may be difficult to see.
- Use gloves or tweezers to handle any worms until you can identify them.
- Flatworms or hammerhead worms can be toxic in certain circumstances, so wash your hands if you accidentally touch one! Put them in a jar with rubbing alcohol or in a bag to freeze them before you put them in the trash.
- You can also dispose of jumping worms after leaving them in soapy water or in a sealed bag in the sun.
- Be sure not to cut-up any non-native worms to get rid of them because some cut-up parts can grow a whole new worm!
Article written by Carol Anne Reynolds, Extension Master GardenerSM Intern.
For more information:
Earthworms:
Earthworm FAQs for Teachers
National Geographic Kids – Earthworm: https://kids.nationalgeographic.com/animals/invertebrates/facts/earthworm
NCSU – Earthworms in Turf: https://www.turffiles.ncsu.edu/insects/earthworm-in-turf/
NCSU – Jumping Worm Fact Sheet: https://content.ces.ncsu.edu/jumping-worms
UNH – Extension – Plant Sales and Jumping Worms: https://extension.unh.edu/resource/plant-sales-and-jumping-worms
Terrestrial Flatworms, Land Planarians, and Hammerhead Worms:
NCSU Extension: https://content.ces.ncsu.edu/terrestrial-flatwormshammerhead-worms