There has been a lot of press of late concerning an invasive earthworm from Asia now found in 15 states in the Midwest and in Nova Scotia. These earthworms, known as jumping worms, look like “regular” earthworms with one exception: the light-colored band that wraps around the worm, the clitellum, goes all around its body. It only goes about three-quarters of the way around the earthworms that are here already.
In addition these new worms really wiggle and thrash about if you try to catch them. They are perfectly harmless, so it is OK, but this is distinctly different behavior than our existing earthworms.
Actually, all earthworms in Alaska are invasive. Some came up in bags of soil, some were purchased for vermicomposting, some hitchhiked in houseplant pots and more. I often get questions from readers who are not familiar with earthworms. People don’t know about their castings, which form “bumps” in lawns. They are actually a good thing as they contain a lot of nutrients.
The problem with these new invasive worms is that they eat all the organic matter in soils and do so too quickly. Actually, they are after microbes on the material, not the organic matter itself. However, in order to eat them the material has to go through the worm.
These worms can also eat roots of some plants if there is nothing else for them to consume. All of this activity has disastrous consequences: No new soil is made once the organic matter is used up and there is a loss of plants. The not-so-obvious impacts are on the biome. Consider insects that depend on the missing plants and the same for mammals, like moose. You get the point.
I am not sure if these worms would make it here given the length of our winters, but they survive in Northern Michigan, so why wouldn’t they do fine here? In any case, we don’t want to find out. These are not the kind of earthworms we want in Alaska. They could devour the debris in our forests’ understory. With our short season, things would have a difficult time growing back. Oh-oh.
So what do we do? Well, first of all, we should remember how worms get here. We bring them in. They don’t move fast enough for them to travel by themselves from the Midwest to, say, Anchorage. We will be the ones that transport them here. In Michigan, fisherman buy them as bait and then toss any left. Most of us don’t use worms here in Alaska’s streams and lakes. If you do, dig them out of your own yard instead of buying them from some source that could care less about Alaska.
We don’t have a worm police force so all we can do here is watch and check. My advice is not to buy worms from Outside sources. And, if you must buy worms from any source, check them, indoors, before you use them in your yard.
If you see a worm that wildly wiggles and giggles when you touch it, check to see if it has a complete clitellum. Actually, if you see a real wiggler, put it into a plastic bag and toss it into a freezer. Once frozen you can check the clitellum a little easier. If you think you have one of these dancing worms, report it to the Alaska Division of Agriculture folks — and to me. We can figure out what to do from there.
So, heads up. Watch for dancing worms. In the meantime, I’ll warn you about hammerhead worms or “broad-head planarians.” These predator “worms” can grow a foot or so long. You might want to look them up. These are also now being found in the Lower 48. Yikes!
Jeff’s Alaska Garden Calendar
Alaska Botanical Garden: Sign up for summer camp. Lots of classes. Plant sales in mid-May; members get in first. Join. www.Alaskabg.org
Flowers to start from seed: Dahlia, schizanthus, nigella, phlox, portulaca, nemesia, marigold, nasturtium.
Vegetables to start indoors: Edible soybean (Edamame)
Rhubarb: If you must have it early, cover your plants with a box or bucket and stand back. Remember the leaves are poisonous. Only eat the stems, which you gently pull and twist off. Don’t cut with a knife.
Bird feeders: Take down feeders ASAP. The bears are up and you don’t want one wandering in your yard because of some sunflower seeds. It isn’t fair to you or the bear.