The First Worm Of Spring

We finished the first project of the spring. I didn’t think it would go as easily as it did – especially after we discovered the first worm.

Our task was simple. Clean out the section between the new succulent beds in the front of the house and the path. At one time, this area was home to bunches of daffodils and huge clumps of violets. All this growing in a layer of decomposing bark mulch. Last fall I thought I relocated all the daffodils; guess I missed a few. The madman is accusing me of shirking my relocating duties. And, those violets, I have no idea where they came from, I thought I moved them, too.

Soil For The Peppers

Anyway, over the past 10 years, most of the mulch had decomposed into perfect soil for the madman’s hot peppers. His goal was to sift his precious soil, removing debris like rocks and weeds. The sifted soil would be placed near the compost bin so he could mix the two together for planting pots in his row of death.

The first few shovelfuls sifted beautifully, and the madman felt the project would be done in no time. Then I found a worm. At one time, we’d welcome these critters with glee. After all, worms are good, aren’t they?

Last fall we got a question from a reader about Asian jumping worms. In Connecticut, scientists have identified at least three species: Amynthas agrestis, A.tokioensis and Metophire bilgendorfi. We looked at the body on the sifter and began our discussion of worms. What’s to discuss? We all know what a worm is. We all grew up with them and in our collective memories, worms are good.

Worms

“Most of them aren’t native, you know,” the madman says. “In fact, you may never have seen a native earthworm.” Generally, in Connecticut the few native worm species are found around rivers, ponds and lakes, not in your garden.

The early colonists inadvertently brought the earthworms to America. They arrived in root balls and in the dry ballasts of ships. And, the worms were welcomed into the gardens because they could break up the soil, making it easier for plants to find nutrients and water. Earthworm activity is especially important in a no-till system like the madman’s raised garden beds. He thinks of them as free garden help. They dig drainage tunnels and pull organic material into the soil. Their castings (excrement) combine minerals and organic matter that he calls free fertilizer.

Good For Garden, Bad For Forests

Of course, there’s always a downside. Remember they are not native. Unfortunately, the actions we love in the garden are not good for our native forests. Here, the health of the soil relies on the slow decomposition of leaf litter. Native plants require a spongy, organic leaf litter layer to germinate and grow properly. Worms, on the other hand, feel it’s their job to break down leaf litter as quickly as possible. Without a good leaf litter, invasive plants find it easier to gain a foothold – and none of us should want that.

To the horror of forest ecologists and gardeners, an Asian cousin of the worm has arrived. The Asian jumping worm. How it arrived doesn’t really matter anymore, but how to get rid of it does matter because this is one nasty worm. It has been referred to as a night crawler on steroids who can eat its way through a good layer of mulch in six months.

What Is It?

That’s why I was looking at the worm on the sifter. Good guy? Bad guy? When they are very small, it’s hard to tell. The Asian jumping worm is an annual species, killed by the frost. An adult worm won’t survive our Connecticut winters, but it leaves behind eggs in insulated cocoons that will survive the coldest winter.

With warmer temperatures in the spring a new generation hatches and starts to work on the top few inches of the soil surface. Any organic material gets decomposed very quickly. And, that’s the problem. These worms leave behind large granular castings that alter the structure and chemical balance of the soil. This altered soil contains few nutrients and is subject to erosion.

Hatching Begins

As temperatures get warmer in April and May, hatching begins. Hatchlings are usually less than 1” in length. Throughout the next couple of months, these worms will grow, constantly munching on your nice organic mulch. Also, they don’t stay in one spot, but move around at an alarmingly quick rate. They can infest 17 acres in one season. On the other hand, the European Earthworm (Lumbricus terrestris) is lucky to move 30’ in a year. No wonder our foresters and land managers are shaking in their boots.

So, how do you know if you have jumping worms in your garden? This time of the year, you won’t find adult worms, but you will find signs from last year’s activities. Look for a grainy consistency in the top layer of your soil – something like coffee grounds only slightly larger. Also, make note of any areas where your mulch is breaking down faster than you think it should.

Not Much Control

Currently, there are no biological or chemical methods for controlling these worms. Soil solarization promises some success, but more research is needed to determine the best methods for home gardeners. That leaves us with hand picking. Back to my quandary, good worm? Bad worm?

Identification

I’ve been telling him we had them for a while, and I thought he was just in denial. But he insists that these were the same worms he would find when digging for bait at Highland Lake. Back then, he hated them – so did the fish. The worms moved too fast, and the tails always broke off. If they were around in the 1960’s, how could they be a “new” invasive species, he thought.

We really can’t explain this, but he is now convinced that we have them, and we need to step up our control methods. He actually joined my removal efforts last year. Whenever we go to the garden, we bring a bucket of cider vinegar and just pickle the worms we find. Right now, it seems that the worms are confined to a couple of beds and we want to keep it that way until they’re all gone.

Identifying the adult is easy. They move like snakes, fast and slithery. Their bodies are hard and have a metallic appearance. Near the head, these worms have a clitellum, a light-colored ring that circles the entire body – it’s not raised like the clitellum on a night crawler. Since juveniles lack the clitellum, they are more difficult to identify, but they do move quickly, perhaps the best tip-off you have. Again, all these jumping worms will be in the top layer of your soil.

Prevention

Since we now know that the egg cocoons can survive a couple of winters, we realize that we’ll be fighting these worms for a while. We know our best weapon is prevention. Here are some things you can do to help limit the spread.

Above all else, avoid bringing worms onto your property. If you use an outside source for mulch or compost, make sure the material has been appropriately heat treated. Don’t buy worms for your compost pile unless you can be certain that what you buy does not contain jumping worms. Buy bare root plants whenever possible. In fact, consider growing your own. Be careful of plant swaps. When removing garden waste, don’t inadvertently introduce garden soil to a natural area.

Clean, Clean And Clean

And practice good garden hygiene. Clean your tools as you move from bed to bed. We like to use isopropyl alcohol because it is easy – we keep alcohol wipes and a spray bottle handy in the garden right next to the bear horn.

Finally, think of your feet. We humans are very good at moving things around without even knowing it. A good practice in the garden is to “arrive clean, leave clean.” Although this campaign started in Australia to stop the spread of invasive plants and diseases in their natural areas, it applies to your garden. So does the “Play, Clean, Go” initiative in our own National Parks. In fact, if you plan to take a break from gardening this summer, head over to the PlayCleanGo website and take their pledge. We did.

Now we’re going to have some hot cocoa before we go on a worm hunt.