Reusing Compost
By Henry J. Holcomb, The Philadelphia Inquirer
Jun. 21–A decade ago, the booming growth of Chester County collided with its thriving mushroom industry, which supplies grocers and chefs as far west as the Rockies.
Growers were finding it harder to dispose of the compost used to grow mushrooms. That problem has spawned two growing businesses. One of them, Laurel Valley Soils Inc., is providing the specially blended dirt for 386 trees that will be planted at the World Trade Center Memorial in New York and at other high-profile places.
The other, Skyland USA L.L.C., is blending special soils for green roofs, an environmentally friendly concept that is popular in Europe and starting to catch on here.
Their initial success is encouraging others to get into the mushroom-compost-recycling business, landscape architects and botanists say. And that is good, they add, because healthy, fertile dirt in the Philadelphia area is getting harder to find.
The key ingredient of these new products is called “spent mushroom substrate.” When removed from the mushroom-growing houses, the substrate needs to be handled with care. If it gets into the water supply, bad things happen to the environment — massive algae blooms in the Chesapeake Bay, for example.
When the area was mostly rural, the used material could be spread over open land, and it would gradually disappear. But nearby open land has grown scarce, and this region’s mushroom industry, the nation’s largest, is turning out more and more of the products as they gain favor among advocates of healthy eating.
In 1999, several growers “were sitting around this table brainstorming about what to do with the stuff,” said Glenn G. Cote, general manager of Laurel Valley Farms, a cooperatively owned enterprise that employs 30 people and has made mushroom compost since 1973.
The compost cannot be reused for mushrooms, but there are nutrients left that are beneficial for other plants. “We knew the material had value,” Cote said. “The problem was, we had so much of the stuff.”
The seven growers that cooperatively own Laurel Valley Farms, of Avondale, decided to invest $1 million to form Laurel Valley Soils Inc. and see if they could turn the used compost into something people would buy.
“Others had played around with the idea, but no one had invested with such passion in solving the problem,” said sales manager Jake Chalfin.
They hired scientists to help design what they would make. At their operations in Avondale, workers blend and stir long rows of decomposing material. Wisps of steam rise from the piles along with odors that encourage keeping your truck window rolled up.
Getting the blend just right can be tricky. Laurel Valley Soils sometimes sends samples by overnight mail to a California laboratory that tests the material for nutrients, density and weight.
Tons of used compost are trucked back to the secluded area where the original compost is made by blending tons of straw, hay, manure-laced hay from the region’s horse stables, corncobs, and droppings from nearby poultry farms.
Laurel Valley Soils recycles this material after mushrooms have been harvested. The privately held company would not disclose sales or earnings. The owners say it is making money. And the soils and compost they blend are winding up in high-profile places — the planter boxes at the Philadelphia Eagles’ Lincoln Financial Field, for example.
This month, truckloads of a special blend are being delivered to Englishtown, N.J., where 386 trees are being grown for the World Trade Center Memorial Foundation. Other customers include the Brooklyn Botanic Garden, Central Park Conservancy, and Longwood Gardens.
Senior head gardener Louis Provost, who cares for 10,000 kinds of plants at the 97-year-old, 52-acre Brooklyn gardens, said he liked how “clean, weed-free and consistent” the Laurel Valley products he buys are. “It can be put down as a mulch one season. Then you can till it in to improve soil biology, rather than having to rely on chemical fertilizer,” he said.
McCloskey & Faber P.C., a Blue Bell landscape-architecture firm, used Laurel Valley soil at the Wegmans supermarket in Warrington. They turned to the small company at the last minute, when dirt supplied by its contractor broke down when watered.
“We were in a real pinch,” said architect Chris Isenberg. “They saved us and saved the project.”
New sources of good dirt are needed, Isenberg said, because, “unfortunately, most of the soils in our area are disturbed by something that has happened on the site.” With fertile topsoil becoming hard to get, “most townships are not allowing soils to leave their township,” he said.
Laurel Valley Soils, with nine employees, says it sells about 150,000 cubic yards of topsoil, a blend of compost and other soils, and about 50,000 cubic yards of 100 percent compost, which can be added to other soil. “During spring and summer, we keep 12 to 15 tri-axle dump trucks busy,” said Joseph DiNorscia III, the soil operation’s general manager.
The newer venture — Skyland USA — provides specially blended lightweight soils for so-called green roofs. These gardens replace traditional roofs. They absorb rainwater to reduce storm-water runoff, reflect less heat, and are often promoted with tax breaks.
“In Germany, 120 million square feet of green roofs are being built a year,” DiNorscia said. “Last year, we did five million square feet.”
With high-rise living gaining favor in urban areas, Cote and DiNorscia believe their green-roof business will soon take off. Instead of looking down on ugly rooftops, Cote said, “imagine looking down on gardens. It will be a much more pleasing environment.”
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More about the region’s mushroom business and what the industry does with its used soil at http://go.philly.com/mushroom
Contact staff writer Henry J. Holcomb at 215-854-2614 or hholcomb@phillynews.com.
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