Green is the new crimson at Harvard University -- at least when it comes to the Ivy League school’s grass.

After a successful one-acre pilot project that replaced toxic fertilizers with an organic approach -- composting, synthetic nitrogen and microbes included -- landscapers are ready to expand their practice university-wide, the New York Times reported.

The Harvard Yard Soils Restoration Project started this past spring, when landscapers banned pesticides, herbicides and other toxic chemicals from a patch of grass in Harvard Yard. Within months, soil became less compact and roots grew 3 to 5 inches. Landscapers also found they were able to reduce irrigation by 30 percent, saving 2 million gallons of water annually. And on a therapeutic note, trees treated with compost tea are on the mend after suffering from leaf spot and apple scrab.

“Our goal is to be fully organic on the 80 acres that we maintain within the next two years,” said Wayne Carbone, Harvard’s manager of landscape services. (Carbone also estimated the school can save $35,000 by composting grass clippings instead of trucking them off campus.)

The greening of Harvard Yard began in earnest last year, when the university’s president, Drew Gilpin Faust, launched an effort to reduce greenhouse gases by 30 percent by 2016.

Around the same time, a fellow at Harvard’s Graduate School of Design named Eric Fleisher teamed up with university landscapers to see what impact microbes could have on Harvard Yard’s battered lawn. In addition to the one-acre stretch in the middle of the Cambridge, Mass., campus, Faust soon adopted the organic program at the official residence of the president on Brattle Street after seeing a display by Fleisher and company.

“The lumps of soil showed how grass grew when treated with chemical fertilizers and how it looked when treated organically,” she said. “I think it’s an integral part of the larger effort to advance sustainability at Harvard.”

To be sure, Harvard Yard takes a beating like other college campuses. Between 6,000 and 8,000 people trample Harvard’s grassy campus daily. During graduation festivities, that number climbs to 10,000.

But the organic approach has made the lawn less vulnerable by relying on the natural “give-and-take” relationship between the fungi and bacteria and plants. In short, while fungi and bacteria consume carbohydrates exuded by roots, they give back water and phosphorus. In turn, they are eaten by protozoa, which convert the bacteria’s protein to nitrogen, which feeds the plants. Adding compost puts the process in high gear.

“Once you get that nutrient cycling system going,” said Fleisher, the Harvard fellow who is director of horticulture at the Battery Park City Parks Conservancy. “It can produce 150 pounds of nitrogen an acre. With that kind of available nitrogen, why would you fertilize?”

At Harvard, green is the new crimson
The grass is greener – quite literally – at Harvard University, where landscapers have swapped out toxic fertilizers in favor of an organic approach.