A day after Sarah Smith served her favorite Darjeeling to her neighborhood book club she steeped a much different tea in her musty shed. Under a low light, she tossed several cheesecloth bags bulging with organic compost into a chubby pot of water. Three days later, she fished the bags from the pot and said, “It’s ready.”
Sarah didn’t serve this tea to her neighbors. After she strained the potion, she poured it into a backpack sprayer and applied an even dose over her front lawn. She claims that her concoction, called compost tea, energizes her lawn without contributing to groundwater pollution. Sarah considers compost tea chicken soup for the soil.
Proponents claim plants love it. Compost tea guru Dr. Elaine Ingham, in her book The Compost Tea Brewing Manual, argues that it provides complete, cost-effective plant nutrition. The trade magazine BioCycle, in an article Understanding Compost Tea, promotes compost tea as a preferred crop fertilizer. San Francisco’s Presidio Trust finds that compost tea increases root growth and reduces turf disease when applied to golf course turf.
Green industry doubts linger. Fine Gardening, in an article The Jury is Still Out on Compost Tea, calls compost tea a watered-down version of the source compost, minus the beneficial carbon compounds that feed soil borne microbes. Organic Gardening, a magazine that preaches compost benefits, admits to their own inconclusive compost tea field trials. Sarah’s landscape gardener Buzzy Smith adds: “Doesn’t hurt, but the grass doesn’t get much of a kick from it.”