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Worm Castings Wiggle Into the Spotlight

By: Eric Vinje Published: 14 Jan, 13 Updated: 29 Oct, 18

Rich in nutrients and microorganisms, castings are the super-charged digested soil that worms leave behind.

Worms & Castings The mainstream press is catching up with what we organic gardeners already know. This article in The New York Times details new research showing that using worm castings helps plants “grow with more vigor, [making] them more resistant to disease and insects, than those grown with other types of composts and fertilizers.” One of the big reason for this is one we’ve long championed: microbes.

The story quotes Norman Q. Arancon, an assistant professor of horticulture at the University of Hawaii at Hilo, who says that “the earthworm’s digestive process, it turns out, is a really nice incubator for microorganisms.” Here’s the take-away from this brief section of the story:

. . . these microbes, which multiply rapidly when they are excreted, alter the ecosystem of the soil. Some make nitrogen more available to plant roots, accounting for the increased growth. The high diversity and numbers of microbes outperform those in the soil that cause disease.

Arancon also points out a fact that’s Bible and verse to organic growers: soil that’s seen heavy use of artificial fertilizers and pesticides is deficient in these microbes. This is why compost, which is technically not a fertilizer, is such a valuable amendment. It infuses the soil with microbes which make it easier for plants to use the nitrogen and other nutrients that are already there. And it fights plant disease.

The other interesting aspect to the story is that worms are big business, not in the old worm-ranching sense, but as a solution to waste disposal problems. NPR recently reported how North Carolina’s Charlotte Douglas International airport has put some 2 million red wigglers to work “processing” their organic waste (kitchen scraps and discarded food from both the terminal and arriving aircraft). The result? CDI has reduced its contribution to the local landfill by 70%. The end product of course is a natural agricultural supplement that doesn’t deplete farm soil of its microbes. The airport uses it to keep its landscaping healthy and growing. Another example is California Soils, a company that uses worms to recycle old cardboard, right down to the glue that holds it together (turns out the glue is a source of nitrogen).

All of this press attention comes at a time when organic gardeners and farmers are beginning to see their practice, if applied large scale, as the key to saving the world from many of the environmental disasters it faces. (The Los Angeles Times had already gotten on the worm compost bandwagon a while back.) This is certainly an illustration of one of our favorite sayings: from small seeds grow great things. Of course, the home organic gardening movement, well-rooted and growing strong, is no longer a small thing. Even the country’s national dailies of record are taking note.

Oh, and one other thing. The Times also recently ran an article rating composters, mostly of the indoor sort, for urban dwellers (in other words, ones without backyards). While us long-time composters will get a laugh out of some of what’s said in the story, I’m sure it got a lot of environmentally minded apartment dwellers thinking. Guess which kitchen composter was favored.

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Eric Vinje

Eric Vinje founded Planet Natural with his father Wayne in 1991, originally running it as a grasshopper bait mail-order business out of a garage.

Eric is now retired, but is still a renowned gardener known for his expertise in composting, organic gardening and pest control, utilizing pesticide-free options, such as beneficial insects.

Eric believes when you do something good for the environment, the effects will benefit generations to come.