Landscape architect Martha Schwartz once said that Americans treat nature like Victorians treated women—as either virgins or whores. But our back yards can be places where we can experience nature and where beautiful plantings that are also ecologically beneficial need to be. This was the message of Thomas Rainer, a renowned landscape architect and author of Planting in a Post-Wild World: Designing Plant Communities for Resilient Landscapes at the 2017 Massachusetts Gardening Symposium in September.
Rainer told the packed auditorium at the Westford Academy that as truly wild spaces have become increasingly scarce, parks and gardens are the way many people gain the experiences with nature that they crave. He pointed to the success of the High Line, a park built on an abandoned railway in New York City that mimics naturally occurring and meadow plantings, as evidence of this trend. At the same time, plants are increasingly being used to provide ecological services such as cleaning storm water, sequestering carbon, and feeding native pollinators.
Rainer advocates taking our cues from the way plants grow in the wild to create designed plantings that are more diverse ecologically and easier to maintain. Americans have developed a peculiar habit of planting individual shrubs and perennials in a sea of mulch, a process that is high maintenance and provides few ecological benefits. In nature, herbaceous plants cover every inch of soil, which Rainer refers to as “green mulch.”
Rainer laid out his approach to planting design that classifies plants based on the way they behave in nature. The structural layer includes most trees and shrubs as well as taller perennials and provides the backbone of the planting. The seasonal theme plants, which Rainer calls the divas of the garden, provide the pops of color and should be arranged in drifts that repeat in the landscape. These plants, which include the various species of Salvia, Amsonia, Monarda, and Solidago, should be selected to provide color throughout the growing season. Over half of the plants should come from the ground cover layer, which is the most important layer as it creates the conditions for stability. These plants, which include many short grasses and sedges, are aggressive spreaders that hug the ground, providing erosion control and suppressing weeds.
The possibilities for these designed plantings are endless, Rainer says. “Why not have meadows floating through our skyscrapers? Why not use plants to clean our drinking water? Once we realize that nature is not this pristine thing that exists apart from us, that nature is us, we can look at urbanism with a new kind of optimism.”
