Proceeds from the flower show help to fund this work—and, by extension, promote a greener downtown—because in recent years, PHS’s landscape management has grown increasingly organic.
“We are focused on best management practices, and what we have done is move from a more synthetic to a more organic approach, building soil health with compost and compost teas instead of relying on traditional methods of treating the symptoms,” says Fran Lawn, the society’s director of landscape management and training. “Instead of ‘Let’s fix the plant by applying some fertilizer,’ we look at the soil, building the foundation for healthy plants versus trying to fix the problem at the top.”
Urban public landscapes deal with a harsher environment than most home gardens. Vehicular and foot traffic, pollution, and heat reflected from paved surfaces all cause plant stress, which in turn can leave plants more vulnerable to diseases and insects. PHS is creating healthier public landscapes through a holistic approach: using plants best-suited to the cultural conditions in which they grow; improving soil biology; allowing a natural balance between predator and prey insects; and not using synthetic herbicides, pesticides, or fertilizers.
It seems to be working, Lawn says. “We’re seeing improved plant health—they’re more vigorous, they look better, and they’re more able to cope with the constraints of an urban environment.”
The transition to an organic approach began with research and field trips to consult experts in sustainable horticulture and soil microbiology, including Eric T. Fleisher at Battery Park City Parks Conservancy in New York and Elaine Ingham, Ph.D., former chief scientist at the Rodale Institute. The learning process continued through informal meetings of a consortium of public garden staffers to compare notes on what worked, recalls Nancy O’Donnell, who oversees PHS public landscapes design.
“We rewrote our specifications to reflect organic practices, but we brought our contractors into the conversation and educated them before we made the switch. We wanted to make sure they would be able to perform well,” she says. The idea was to influence not just a few contractors but the industry at large.
Last year, the educational component switched into high gear when PHS partnered with the Northeast Organic Farming Association (NOFA) to host the Mid-Atlantic NOFA Accreditation Course in Organic Land Care, in January and again in December.
“It is geared to land managers, but also to designers and educators, and provides a very extensive background in organic land-care practices,” says Glen Abrams, director of sustainable communities at PHS. He would like to see more people demand this type of expertise, and points out that NOFA’s program enables homeowners to identify accredited organic landscape maintenance professionals.
“There needs to be an educational campaign about the importance of managing landscapes while respecting the complex ecological systems that are at work,” he adds. “What is so important in organic land care is understanding these systems, and really doing no harm.”
The 2014 Philadelphia Flower Show will be held March 1 through 9 in the Pennsylvania Convention Center. For more information, visit theflowershow.com.
Photography by Punchstock, and the Pennsylvania Horticulture Society
Originally published in Organic Gardening magazine, February/March 2014