There's a new miracle soil that makes plants grow faster and eliminates weeds -- and you'll never guess what it's made of.

Called SmartGrow, it's packaged in a factory in Florida City, Fla., but the raw ingredients come from China.

The secret? Human hair, according to a report from the American Public Media radio show "Marketplace."

Mats woven from hair cost $4 apiece, crowd out weeds, trap water better than dirt and are very environmentally friendly.

But because it all comes from Chinese barbershops, it's always black.

That's fine with Blair Backer, CEO of World Response Group, Inc., which makes SmartGrow.

"Blond tends to be slightly less nutritional," he admits. "Slightly. I'm not going to say a word."

• Click here to read (or hear) the rest of this story at the 'Marketplace' Web site.

• Click here for the SmartGrow Web site.

• Click here to visit FOXNews.com's Natural Science Center.