BEFORE THE WORMS feast on it, their grub is composted and cooked in a vat. The food and the worms are placed together on a conveyor belt, creating a feeding frenzy that would make Homer Simpson sick with jealousy. "On one end, you put in cooked material, and the worms eat that, and [when it's gone], they'll move out of their own poop and into new food," says Szaky. As the worms eat, the conveyor belt moves in the opposite direction of their travel at the pace of their ingestion, about an inch every five hours. "They're on a perpetual conveyer belt - food at one end and poop out the other," he says.

The poop alone isn't the product, of course. To get the actual plant food, which is technically known as vermicompost tea, TerraCycle adds oxygen and water and then brews and stirs the mixture for 48 hours. "We make this really potent organic tea, and the liquid becomes our plant food," says Szaky. The brew then goes into the recycled soda bottles, which have been cleaned and wrapped in a colorful TerraCycle label, and is sent to retailers. In keeping with the mission of the company to create no waste, TerraCycle takes the by-product created by brewing the tea and uses it as the raw material for other products like potting mix.

None of this would mean much if the resulting plant food, though ingenious, were ineffective. But judging by sales - which have grown from just $70,000 in 2004 to $1.5 million in 2006 to $2.5 million for the first half of 2007 - plenty of consumers think it works. Szaky insists that the 70,000 microorganisms living in it are what make it so powerful; picking up a bottle, then, means buying something that is, in effect, still alive and kicking. "These microorganisms help fight disease; they help bring nutrients to the roots - it's like an ecosystem," he says. "One of the big problems people have, especially in America, is they douse their garden with chemicals, which wipes out all the bugs that live in your garden. But the bugs actually help your garden."