Soldiers of the Soil

 
August 17, 2006

By Valerie Sudol

The Star Ledger

"They are clean, quiet, well-behaved creatures, interesting to watch and even beautiful in the way any organism can be if you just know how to look at it. Put a worm in your hand and watch it expand each segment in turn, arch its back, flex its muscles. You will be won over." -- Amy Stewart in "The Earth Moved"

Do worms make you squirm? Do you think of them, if you think of them at all, as slithery little denizens of the netherworld, crawling witlessly around in the dark? Would you perhaps even characterize them as unlovely and inconsequential?

If so, it's time for an attitude adjustment.

The lowly earthworm deserves not only your respect, but your gratitude, too. Earthworms work tirelessly to improve soil structure and fertility, transforming bits of organic debris and small particles of soil into a nutrient-rich substance than enhances plant growth.

Without earthworms, it would take 100 to 150 years for natural forces like erosion to produce a single inch of topsoil. Earthworms can produce that same inch of fertile, friable growing medium in just a year. If you enjoy the fruits of the soil, the bounty of the harvest, you can't dis the worm.

The father of oligochaetology (the study of worms) was no lesser a light than Charles Darwin, more famously known for his theory of evolution. His last book, published in 1881, summarized some 40 years of intimate research into earthworm behavior. "The Formation of Vegetable Mould Through the Action of Worms, With Observations on their Habits" included some startling conclusions.

Virtually all of the world's fertile land has passed many times through the gut of earthworms, nature's original plough, Darwin proposed. Given their recycling of organic nutrients to the benefit of agriculture, he "doubted whether there are many other animals which have played so important a part in the history of the world." Take that, you fickle housecats and clever sheepdogs.

Darwin estimated that an average acre of garden soil contained some 50,000 worms generating 18 tons of manure or castings every year. In fact, their numbers vary quite a bit more than that, ranging from 20,000 per acre in the flinty soils of Romania to 8 million per acre in a New Zealand pasture. Wherever you are -- short of a paved city street or shopping mall parking lot -- the earth really is moving under your feet.

Uniquely suited to a life underground, the slender earthworm burrows through the earth to depths of 8 feet and more, leaving behind channels that let essential air and moisture into the zone where plant roots live. By alternately elongating and shortening its segmented body, helped along by stiff hairs known as setae and lubricating mucous, the worm can penetrate soils that defy assault by shovel-wielding humans.

As it goes about its work of foraging, the worm drags leaves, pine needles and other detritus into its burrow, facilitating the decomposition of organic debris that returns to the soil elements that can be consumed by plants. But the benefits of worms don't end with tilling the soil and recycling decaying plant matter.

The worm's output -- call it manure, castings or worm poop -- is a high-quality organic fertilizer rich in basic plant nutrients, humic acid, trace elements and beneficial micro-organisms. Odorless and innocuous in appearance, looking much like a handful of finely screened compost, castings are pure garden gold, created through the alchemy of a worm's humble transit through the soil.

"Their work may seem unspectacular at first," writes Amy Stewart in her fact-filled homage "The Earth Moved: On the Remarkable Achievements of Earthworms" (Algonquin Books, 2004, $24). "They don't chirp or sing, they don't gallop or soar, they don't hunt or make tools or write books. But they do something just as powerful: they consume, they transform and they change the earth."

Calling all Worms

Earthworms are every gardener's silent partner, their presence a measure of soil fertility. But which worms, exactly, do we find most useful?

While North America has about 100 native species of earthworms (and the world some 5,500), three European species are the commonest: the nightcrawler, the red wiggler and the red worm. Their invasion was accidental and unnoticed as they hitched a ride to the New World in the potting soil, ship's ballast and livestock bedding of early settlers.

By now, these worms are ubiquitous, but they are not alike in their habits or habitats.

The nightcrawler Lumbricus terrestris -- Darwin's worm -- is found in any spadeful of reasonably rich soil under lawns, gardens and meadows. Hardy in our climate, this worm burrows deep into the ground where it can escape drought and cold winter temperatures.

It emerges after dark, when predators like birds, turtles and toads are inactive, to forage for dead plant matter. They are commonly seen (and often collected by fishermen) after rain, which lubricates their progress across the ground.

If you want to encourage earthworms to inhabit your soil and do their good works, there are a few points to keep in mind.

Avoid deep and frequent tilling, since this destroys their burrows and can injure those caught under the blades. A worm cut in two may regenerate its missing parts, but you won't get two worms from one; a section lacking a head is not a potential new worm but merely compost. Tilling also dries out the soil and speeds decomposition of organic wastes on which the worms feed.

Adding organic material, on the other hand, helps keep the worm population well fed. A layer of compost, mulch, chopped leaves or grass clippings will soon be incorporated into your soil with the help of actively feeding worms.

While herbicides pose little threat to earthworms, according to a study from the University of Wisconsin, pesticides can be deadly and should be avoided. Adding lime to acidic soils can help keep the pH reading close to the neutral point worms like.

The red worm and red wiggler, Lumbricus rebellus and Einsenia foetida respectively, also play a starring role in soil improvement but can't live year-round in our garden soils since they need higher temperatures to live and breed. These two represent 80 to 90 percent of the worms produced commercially for vermicomposting -- maintaining a colony of worms in a bin expressly to consume vegetable waste and produce nutritious castings.

There is an entire subculture out there devoted to worm bin maintenance with a zeal that is nearly religious. A classic on the subject, Mary Appelhof's "Worms Eat My Garbage" (Flower Press, $10) has been in print since 1982 and will tell you everything you need to know about setting up a worm composting operation.

The basics are simple -- provide a moist bedding (shredded newspaper is fine) and periodically toss the worms your kitchen scraps. Vegetable parings, egg shells and wilted produce are good fodder, but as in the outdoor compost heap, meat, oil and dairy products are not. Within three to four months, you can begin harvesting a rich bounty of worm castings for the garden.

One popular ready-made worm bin, the "Can-o-Worms," is a multi-level worm composter that encourages worms to crawl up to the next "floor," leaving their castings behind for convenient collection.

There is one caveat regarding these helpful, non-native species -- call it the worms' dark side. In the northern United States where woodlands evolved after the Ice Age without worms and dead plant material is recycled very slowly, foreign-born worms are denuding the forest floor.

In Minnesota, worms are consuming in a single season fallen leaves that once took five years to decompose into a fertile, spongy litter known as duff. Without this layer, native wildflowers and tree seedlings are vanishing along with once-abundant creatures like salamanders, and noxious invasive weeds are moving in.

Beyond urging fishermen not to dump their left over worms, science has no solution to the problem. It's the one instance where the worm's stellar reputation, unsullied all these years, has been left in the dirt.

Getting Started

Let's say you're a born-again worm convert, prepared now to give worms their due, but don't know where to begin. Take heart -- there are several New Jersey entrepreneurs ready to help you out.

Jersey Devil Organics is a worm farm in Piscataway launched less than a year ago by former college professor Merl Coslick with his son David.

If the term "worm farm" conjures up wide open spaces and corrals of rambunctious livestock, you're way off the mark. This farm is housed in a large, climate-controlled garage bay and the work of its 750,000 inhabitants is virtually silent. In ranks of stacked buckets that fill the space, nightcrawlers are steadily producing the company's two products: worm castings and more nightcrawlers.

A bucket of 150 small worms or a 30 pound bag of castings goes for $25. The worms can live as long as seven years in the garden, Coslick says, collectively producing as much as three-quarters of a ton of castings per year. With 50 million fishermen and 70 million gardeners nationwide, he figures the potential market is as enormous as the work force is compliant.

"The worms are quiet, never stop working, don't complain and don't demand pensions or benefits," he jokes. "Still, things can go wrong -- this is no get-rich-quick scheme."

A larger operation is Ken Chiarella's Worm Man's Worm Farm, operating in Monroe Township since 1996. What started out as a hobby for an avid gardener has grown into a business supplying not only worms, but also beneficial insects and an array of wormy critters and insects used to feed reptiles.

You can order red wigglers, a related Belgian species, Eisenia hortensis, also used for composting, and common nightcrawlers.

The worm business that has attracted the most attention as an offbeat and innovative start-up would have to be TerraCycle, a company led by 24-year-old Tom Szaky that has already passed the million dollar mark this year in sales. Not bad for a four-year-old company started while Szaky and collaborator Jon Beyer were still Princeton University undergraduates.

Marketing neither worms nor castings but dependent on both, TerraCycle produces a line of ready-to-use liquid fertilizers made from steeped "worm poop." The eco-friendly product is packaged in used soda bottles which would otherwise clog landfills as part of the waste stream. From the materials of production to the cast-off furnishings of the plant in Trenton, the business is all about recycling -- garbage in, profit out.

"We started out with the idea that you could make something really good out of garbage," says Szaky. "You might say we feed on the underbelly of capitalism."

The company spends little advertising its product but it does get the word out, partly through the "Bottle Brigade," a program that involves 1,200 churches, schools and other non-profits in collecting empty bottles for fun and profit (five cents each with labels, six cents without). It also can attribute its fast growth to targeting major mass marketers for distribution -- Home Depot, Wal-Mart, CVS drugstores.

TerraCycle now offers three "flavors" of worm tea -- all-purpose, orchid and African violet -- that take advantage of the differing composition of worm casting batches. ("Like wine, there are different vintages," says company spokesman Barry Brinster.) They sell for $3.79 each.

Starting next year, Home Depots in the Northeast will introduce a concentrate for lawns, a peat-free potting soil made from brewed castings, compost and paper waste, and a seed-starting tray made from paper pulp and filled with worm castings.

Szaky's ambitions for TerraCycle fertilizers are simple: "We want to become a major competitor to Miracle-Gro," he says. "We think we can be the most popular all-organic fertilizer in America."

It couldn't happen without the lowly worm, which transmutes ordinary organic waste into a potent plant growth booster. Inch by inch, one leaf and soil crumb at a time, the worm teaches us that even the humblest discards of the natural world can hold the glint of gold.

Worm castings are a unique organic fertilizer, containing plant growth hormones that even homemade compost lacks.

Analysis by the University of Wisconsin showed that casts contain five times more nitrogen, seven times more phosphorus, 11 times more potassium, three times more magnesium and one-and-a-half times more calcium than surrounding soil. Unlike the "food" in some synthetic fertilizers, these nutrients are excreted in a form easily used by plants.

The waste of nightcrawlers can actually raise the pH of soil with calcium compounds, tests show. Microbes and bacteria that pass intact through the worm's digestive system contribute to the health of the soil, and some of the protozoa release additional nitrogen to the soil.

Some trials suggest that castings can help plants repel disease. The Ohio State extension service found cucumbers, radishes, strawberries, grapes, tomatoes and peppers were healthier and parasitic bugs like aphids and mealy bugs were suppressed. Finally, castings work like all organic amendments to improve soil structure, enhancing both drainage and moisture retention.

Sterile, odorless castings and castings teas are ideal for the novice gardener because they are "goof proof." Although a little goes a long way, measuring needn't be precise since excessive amounts won't burn plant roots -- it just wastes the product. Another good point is that these worm fertilizers are non-toxic and won't harm children or pets.

You can buy ready-made "worm poop" fertilizer, which is packaged to have a shelf life of up to two years -- or you can make small batches for immediate use. Soak one part castings to three parts water for 12 to 24 hours. Stir well and use it as you would a commercial product to spray plant leaves and drench soil around the roots.

Here are some suggestions for using solid castings, which can be purchased as "Wiggle Worm Soil Builder," "Wonder Worm Manure" and other brand names:

Add castings to seed furrows and holes for vegetable and annual seedlings. Side-dress plants every two months at the rate of 1 cup per linear foot or 1/2 cup per plant.

Apply 1/2 cup around perennials in spring, summer and early fall; work into the soil being careful not to damage shallow roots.

Add 1/2 inch of castings to containers and hanging baskets every two months. Scratch it into the potting soil and water well.

Mix four cups of castings into planting holes for roses, trees, shrubs and berries.

Spread seven pounds of castings per 100 square feet of lawn to boost established turf. Work 10 pounds per 100 square feet into the top few inches of soil before seeding a new lawn.