Waste farmers: compost and soil products/wastefarmers.com/Denver.

• Position: Agriculture

After selling their composting business, the brains behind Waste Farmers went into manufacturing packaged compost and soil products in 2012. After initially using a small cement mixer and bagging it by hand, the company boomed and sold 30,000 bags in 2013.

Waste Farmers has a consumer brand in Maxfield's and a professional-oriented product in Batch 64. Both are made at the company's "microbe brewery" in unincorporated Jefferson County, and the company also maintains an office at Galvanize, the incubator-meets-shared-workspace-meets-tech-school, in Denver.

"We're continuing to grow and expand,' says John-Paul Maxfield, Waste Farmers' founder and CEO. "We're looking to add another facility to launch new products."

Maxfield calls the company "the antithesis of Monsanto" and Big Ag. "We want to focus on small...