Meeting the Challenges of the 21st Century

Adding Milo's to the Nursery Mix

In an average week, Milo’s Tea Company churns out 350,000 gallons of its famous brew. That’s a whole lot of tea—and a whole lot of used tea leaves. About 15 tons of tea grounds a week, in fact.

Right now, the Bessemer business compacts those spent grounds and hauls them to a landfill.

“I guess you could call it ‘green’ garbage, because it does decompose, but it costs us thousands of dollars a year to drag it off,” says Milo’s VP and COO Jay Evers.

Could those spent tea grounds, Evers wondered aloud to AAES scientist and AU horticulturist Jeff Sibley, somehow be put to use, perhaps in the nursery industry?

And thus was launched a two-year study, sponsored by Milo’s, to investigate the possibilities of using spent tea leaves as a non-soil planting medium for nursery production of container-grown ornamental crops. Sibley and AU horticulture graduate student Daniel Wells went to work on the project in summer 2006. Since then, they have conducted more than 70 different experiments, using tea leaves alone and in varying combinations with pine bark to grow about 30 species of bedding plants and shrubs.

Findings thus far indicate that spent tea grinds are high in nutrients essential to plant growth, have excellent water-holding capacity, are an ideal substitute for peat moss and, particularly when mixed with pine bark, are a highly effective substrate for a wide range of ornamentals.

The study could give tea brewers a regional solution to spent-grounds disposal problems while providing an additional resource for nursery growers.