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UF Research Shows Plants Can Be Grown In Compost – Alternative to peat is environmentally friendly, more economical for growers

By:
Ed Hunter (352) 392-1773 x 278

Source(s):
Sandra Wilson sbwilson@gnv.ifas.ufl.edu, (561) 468-3922, ext. 132

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FORT PIERCE, Fla. — Compost made from wastewater sludge and yard trimmings could replace peat in the pots of many store-bought plants.

Using alternatives to peat would please environmentalists opposed to the continued mining of the natural resource from sensitive lands, said Sandra Wilson, an assistant professor with the University of Florida’s Institute of Food and Agricultural Sciences.

“This will reduce our dependence on peat,” said Wilson. “Environmentalists believe destroying peat bogs also destroys wildlife habitat and vegetation which will take a long time to regenerate.

“But the main point is we have this biosolid waste compost we need to find a use for,” she said. “This could stimulate new markets for the compost, and the nursery industry should realize a reduction in their production costs that could be passed on to consumers.”

Wilson, based at UF’s Indian River Research and Education Center in Fort Pierce, has been studying several species of common perennial landscape plants to determine which ones will thrive when growers use compost instead of traditional media. Her most recent study looked at Mexican Heather, Cuphea hyssopifolia. She said plants grown in compost were just as healthy and vigorous, although a little smaller than plants grown in traditional peat-based media.

“Generally, plants grown in media that consisted of 50 percent compost took just as long to grow to a marketable size and were indistinguishable from plants grown in standard media,” Wilson said. “Depending on the plant species and watering practices, you may be able to use up to 100 percent compost.”

Kevin Kraft, owner of Kraft Gardens in Deerfield Beach, Fla., said most nursery operators are sensitive to environmental concerns and would welcome the opportunity to increase their use of composted waste products. He said the product ultimately needs to satisfy consumers as well as the nursery industry.

“It will take some research that includes growing plants in compost to convince growers that it is viable,” said Kraft, who is chair of the research center’s Ornamental Advisory Committee. “The product needs to be acceptable to the final consumer — so it must hold up well, not have any objectionable odors and not break down too rapidly.”

Kraft said his nursery produces ornamental plants in pots that are used inside residential and commercial buildings so the questions of stability and lack of odor are extremely important. If compost proves to be a viable and less expensive alternative to current products, the industry should accept it, he said.

“It all comes down to the bottom line,” Kraft said. “As a soil-less media, the compost product has to hold up because some of these plants can remain in pots for a year or more.

“Of course, everybody wants to save money and be competitive,” he said. “If your competitors are using it successfully and spending less money, you would want to use it as well.”

Patrick Byers, assistant director of compost and vegetation services for the Palm Beach County Solid Waste Authority, said agencies that produce compost would be delighted if nurserymen like Kraft started using compost to grow their plants.

“As markets open up for organic products and people see compost being used successfully, they will become more inclined to use it themselves,” said Byers, whose facility turns out 190 tons of compost each day. “The increased usage will make it more cost-effective to recycle organic products that are presently going into landfills.”

Wilson said the quality of the compost available to growers is critically important.

“The Palm Beach County Municipal Solid Waste Authority operates one of the top compost facilities in the country,” Wilson said. “They produce consistent, reliable, stable compost of an exceptional horticultural grade.

“A nursery in other areas that doesn’t have this ‘top of the line’ compost facility may not experience the same results,” she said.

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