Growers Go Batty
In the Garden Race

For gardeners looking for a leg up on the neighbors, there's a new animal in the backyard: bats. Or, more precisely, bat guano.

This summer, garden stores and nurseries across the country say fertilizer made from bat droppings has been flying off the shelves. Sales have tripled since January at the Guano Company, a California wholesaler, while at the Worm's Way, a garden supply chain, they've sold more than 20 tons of the stuff this year, a 20% increase from last year. At Green Jeans Garden Supply in Mill Valley, Calif., it's so popular, owner Kevin Sadlier has slapped a new bumper sticker on his VW bus: "I love bat guano."

The general shift to organic fertilizers is a big part of guano's popularity, of course. With homeowners increasingly worried about both the environment and what's going into their food, sales of organics have been growing by about 10% annually, says Bruce Butterfield, research director for the National Gardening Association; they now make up about 10% of the fertilizer industry's $1.2 billion annual sales. That's despite the fact that they can cost up to 20% more than synthetics.

Bat guano's even pricier -- as much as 10 times as expensive as the average organic fertilizer, or up to $10 a pound. So what's the big stink all about? According to gardening gurus, it not only feeds plants, but also helps preserve beneficial micro-organisms in the soil. Even more important, because of its high nitrogen content, it can give the garden an immediate burst of color. "You see the response in days rather than weeks," says Phil Radspinner, commercial sales manager at Peaceful Valley Farm Supply in Grass Valley, Calif.

But, unlike with chemical fertilizers, you can't just make more of the stuff. The guano is harvested from bat breeding grounds, like Bracken Cave, near San Antonio, home to an estimated 22 million bats. To get it, "miners" go in every other year while the bats are at their winter grounds in Mexico. Using a giant vacuum, they suck up the droppings, which have been processed by guano beetles, then bag them and sell them.

This isn't guano's first commercial use. It's been used in everything from gunpowder to mascara, not to mention as a fertilizer -- until gardeners and farmers largely abandoned it in favor of chemicals.

One reason: the smell, which even fans concede is pretty bad. "It smells almost charcoaly, but not in a good way," says Texas garden designer Jill Hickman. In most cases, the odor dissipates in less than a week, especially if the guano's mixed with moist soil. But when Ms. Hickman made the mistake of spreading it on her lawn during a drought, "it smelled for six months," she says.

Mike Griggs, for one, isn't sure what all the fuss is about. Though the Willits, Calif., fertilizer distributor sells almost 100 tons of guano a year, "I'd trade two pounds of chicken manure for 30 pounds of bat guano," he says. "It's just poop."

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