Organic matters: The Yard returns to its roots with help of GSD

What is special about the swathe of grass running the length of Massachusetts Hall to Johnson Gate? It and several other lengths of lawn in courtyards to the north make up the approximately one acre of the Yard devoted to the University’s organic soil revitalization project.

As a kind of “soil lab,” the brainchild of Harvard Graduate School of Design (GSD) Charles Eliot Professor in Practice of Landscape Architecture Michael Van Valkenburgh, the project is managed by GSD Loeb Fellow Eric “T” Fleisher and carefully tended by Wayne Carbone, manager of Harvard’s Landscape Services, and his crew.

On April 16, seeding began with a healthy dose of “compost tea” — a liquid biological amendment — from the brewing vat located just past the entrance to the Yard across from the Science Center. In it are living organisms that will control pests and nourish the soil. Results will be measured biweekly until the first of November. The goal? To demonstrate that grounds grown organically are self-sustaining, lush, and beautiful, despite heavy foot traffic.

Other experiments will be made with a new tree planted on one part of the test plot, and a similar tree planted in another area of the Yard. Comparisons will be made between the growth of the trees — one being treated 100 percent organically, the other in soil that is treated conventionally.

“Unlike conventional soil improvement, we are taking a very different approach,” explains Fleisher. “Instead of applying a topical, chemical fertilizer, our biological approach is to create a chemical change by infusing the soil with biological organisms from the bottom up.”

It all started with a conversation Van Valkenburgh had with Harvard University President Drew Faust last fall as they walked through the Yard. Asked what one thing he would do to protect the Yard, Van Valkenburgh recommended soil remediation, pointing to the loss of trees in the Yard due to soil degradation and compaction. Two rows of tulip trees that once graced the area outside Massachusetts Hall died some years ago, and others have also taken the count only 12 years after they were planted due to soil degradation around the root systems.

“Michael has been working for many years on correcting the plant palette and planting conditions at Harvard Yard,” says Fleisher. “I have been working on building a program at Battery Park City [New York] for the past 19 years, focusing on managing public space through completely organic means, my main focus being on soil.”

After Van Valkenburgh conferred with President Faust, Jeffrey Smith, director of Facilities Maintenance Operations, and Carbone toured Battery Park with Fleisher to observe soil operations. They were impressed enough to try the soil amendment system in Harvard Yard.

With that, a pilot study was launched.

“One of my goals as a Loeb Fellow this year was to prove the transferability of my program at Battery Park City to another organization,” says Fleisher. “Michael and I started working together almost 10 years ago when he started to design the beautiful Teardrop Park at Battery Park City. We have had a symbiotic relationship over the years and enjoy working on adaptive challenges together. I like to think of us as “the micro-macro team” — Michael takes the macro approach to landscape architecture, and I take the micro approach as a soils expert. This project is no exception.”

Unlike creating a new lawn from scratch, the challenge of remediating established soil is that it cannot be aggressively removed. Instead, the lawn is fed periodically with an “organic tea” that promotes beneficial microbial activity in the soil and promotes growth.

A contractor has been retained to conduct the pilot program, according to Fleisher’s specifications, until June when Carbone and his crew will have been trained to take over the soil maintenance program and Fleisher returns to Battery Park City Parks Conservancy where he is director of horticulture.

Members of Harvard’s Green Initiative; GSD lecturer in landscape architecture and senior research scientist at Harvard’s Arnold Arboretum Peter Del Tredici; director of building infrastructure and operations Jay Phillips; Zak Gingo, associate director of residential housing at the Faculty of Arts and Sciences; and Jeffrey Smith are among those involved with the project. Wayne Carbone retained a contractor to conduct the pilot program according to Fleisher’s specifications.

“The lawn takes longer to green up,” said Fleisher, “but it’s more enduring and resilient with our properly executed organic approach.”

An exhibition about the project will be shown from May 2 to June 2 in Gund Hall lobby at the Harvard Graduate School of Design, 48 Quincy St., Cambridge, Mass.