Eugene Weekly : Feature : 4.21.11

Eugene Weekly’s Earth Day Issue:

Carpe the Carp Stalking the elusive *Kentucky tunain Oregon waters

Pretty, Bad Mute swans in Oregonû


Dont Feed the Birds Wild turkeys are really feral


Will Work for Food Nonnative earthworms move slow, compost fast

Crawfish, Crawdad, Crayfish Whatever you call them … theyre invading Oregon


Will Work for Food
Nonnative earthworms move slow, compost fast
By Rachel Foster

It may be hard to imagine life without earthworms, but the common earthworm and almost all its relatives are not native to North America. It seems that they arrived with European settlers. The earthworms appetite for organic matter can create havoc in forest ecosystems, where native plants and animals depend on a deep litter of decaying leaves. But worms are a boon to gardening and agriculture, devouring plant waste as they aerate and fertilize the soil.û

Trask Bedortha

Common earthworms are sometimes sweetly called natures plough. They are burrowers, and spend most of their time below ground, where they consume soil particles and bits of the leaves they pull down into their tunnels. Other species, such as the red worm or red wiggler, are surface dwellers, pursuing a life between the soil surface and its overlying blanket of organic debris which is their food. They can consume half their weight in food each day, and this voracious appetite can be put to work as a disposal system for unwanted yard and food waste.

A surprisingly large part of a communitys waste is discarded foodû ‹ 16 to 20 percent in Lane County. Much of that could be kept out of landfills if more of us composted at home. Sherry Wellborn, a compost specialist with the city of Eugene, believes we should look on food waste as a valuable resource and keep it in the neighborhood.û

Composting with red worms is a good option. Vermicomposting is a well-established practice with reams of literature. The process is odor-free, relatively clean and doesnt require much space. It can even be done indoors, where the worm bin will be active year-round (red worms are sensitive to extreme heat and freezing temperatures). Worms move quite slowly, so the nonnative factor is not an issue if they arent turned loose.

Wellborn joined with Amazon Neighbors to put in a proposal for a neighborhood matching grant from the city to build a new sort of worm bin as a demonstration project. The bin will serve four adjacent households in her immediate neighborhood. The design is inspired by a bin operated by Rodney Bloom for Food for Lane County that has a simple vertical flow system: a box with a horizontal array of nylon ropes stretched internally between the sides of the box, about two thirds of the way down. Digested stuff falls between the ropes into a harvest area below. A door in the side allows you to rake across the underside of the ropes to bring down more finished material.û

To get around rot issues and dispense with the need for carpentry skills, Wellborn proposes using a ready-made, totally recyclable HDPE shipping crate, 30 x 30 x 54 inches high. You will need to cut a hole in one hinged side to form a door, add a fastener at the top of the door, and punch holes to thread 1/4″ braided nylon rope from side to side, two inches on center. (Wellborn believes that Dan Holcombe of Oregon Soil in Corvallis pioneered this vertical flow-through system.)

To put such a bin to work, you place some straw on top of ropes, then layer in moistened, high-carbon worm bedding such as leaves, straw, shredded paper or sawdust (bedding should be moist, not dripping wet) alternating with food scraps or coffee grounds. Then pop in a ball of red worms, which you can probably obtain from a neighbor, if not from your own garden. Keep adding food scraps, covering each addition with bedding. Go easy with onions and citrus peels, Wellborn says, as too much will hurt the worms skin.û

Food scraps can contain a lot of water, so add enough bedding to the keep moisture level moderate. Worms dont like to be too wet, and may leave if things get soggy. The bin will drip, so put it on the ground or on a palette so water can drain away. By the time the average household has filled the bin almost to the top, you can harvest some compost from the bottom, which will lower the level in the box so you can add more material. Harvesting should not bring down too many worms, because they will be working further up the pile by then.û

What the worms are eating is mostly bacteria, as well as fungi, nematodes, protozoa and organic matter. Worms have no teeth with which to bite off pieces of food, but they do ingest particles small enough to pass into the esophagus. Because worms eat and break down potential pathogens, compost made this way should be disease-free. If you put in weed seeds, however, they will still be viable.û

Locate the bin out of the sun, to avoid overheating. When the temperatures drop into the 20s, your worms will need help: either insulate the bin with leaves, blankets, straw, etc., or create a small øhot build” in the pile that the worms can snuggle up to. The hot-build can be food scraps mixed with coffee grounds or manure ‹ something that will heat up fast.

The Willamette Valley has a unique earthworm species ‹ the Oregon giant earthworm ‹ which can grow over four feet long and is threatened by nonnative earthworms, For more information on the nonnative earthworm issue go to and dont release your composting or fishing bait worms into the wild.