Compost using worms, larvae Nutrient-rich matter is result

A redworm from the composting bin.

No one likes maggots.

They're usually found on decomposing roadkill or trash cans with forgotten chicken bones. The legless larvae are the immature growth stage of flies, which are equally annoying. But not all maggots are unwanted.

A few years ago, we started vermicomposting at home. Traditional composting, as most people know, is natural decomposition of landscape waste and kitchen scraps by microorganisms. The end product is nutrient-rich organic matter that can be worked into the garden or topdressed over the ground. Vermicomposting is the same thing, only with worms.

Redworms, or red wigglers, do the work of aerating the compost and adding nutrients through their castings, otherwise known as excrement. Redworms are different from regular old earthworms. They're smaller and feed on food scraps while earthworms feed on soil. You also won't find redworms in our soil. They'll have to be purchased. I found them online at www.findworms.com.

Traditional composting is done outdoors and, as long as it's turned, aerobic decomposition takes place. When a compost pile smells nasty, that's usually because it's too wet and lacks oxygen, resulting in anaerobic decomposition.

Vermicomposting is frequently done in a plastic bin, such as a storage container. There are numerous dimensions, but 2 feet long, 2 feet wide and 1 foot deep is average. Holes are drilled in the top and sides to improve aeration.

In traditional composting, carbon material, or browns, are the food source. This includes fallen leaves, small sticks or straw.

In vermicomposting, the bedding material is shredded cardboard, computer paper or newspapers that are fully saturated, squeezed of excess water and fluffed in the bin.

Redworms will primarily feed on kitchen scraps but avoiding things such as dairy, meat, oils and pet waste. Citrus also is considered a no-no, but I haven't noticed a negative impact when occasionally adding it. Since worms have gizzards to grind up food, crushed egg shells and coffee grounds are good additives.

Throw food inside the container and let them eat. In the beginning, you may need to bury it in the bedding. When the bin is healthy and active, the compost should smell earthy.

Small bins can be kept under the sink, but gnats became a problem. I put the bin outside in a dark, shady place 10 feet from the back door. That wasn't far enough to keep the gnats from wandering inside and setting up camp in our kitchen. Twenty feet was effective. After that, the redworms went to town on everything we threw inside.

We eventually bought a vermicomposting tower (www.compostbins.com) that had a spout at the bottom to collect compost tea. This was added to our watering can, which added a boost of microorganisms each time we watered container plants.

About mid-summer, I noticed the vermicomposter had been overrun by large, flat maggots, which seemed disgusting and wrong. These were soldier fly larvae. And, it turns out, they are much hungrier for kitchen scraps than redworms. Clemson University has a soldier fly digester (http://www.clemson.edu/sustainableag/soldierfly.html) where campus food waste is collected and decomposed. The larvae are harvested before they pupate into flies and can be used as chicken feed or processed into fuel.

In our backyard, soldier fly larvae simply devour everything we throw at them. Watermelon rinds are completely gone in a week. And animals in the neighborhood have taken notice. Every once in a while, the larvae are consumed by a possum or raccoon. But the soldier flies always come back.

The redworms are still in the vermicomposter along with the soldier fly larvae. The redworms are not supposed to overwinter here, only surviving low temperatures of 40 degrees. However, I haven't taken any precautions and they continue to come back year after year.

Every spring, I work the majority of the compost into a small garden, leaving enough in the vermicomposter to start the next season along with fresh bedding. The redworm population rebounds quickly. And by mid-summer, the soldier flies come back, too.

Good tutorial videos for bin construction can be found at www.redwormcomposting.com.

Tony Bertauski is a horticulture instructor at Trident Technical College. To give feedback, email him at tony.bertauski@tridenttech.edu.