Northeast Conservationists Offer Climate-smart Garden Guide Highlighting Native New England Plants
AMHERST, Mass. – An estimated 80% of ornamental plants for sale at garden centers and other outlets are non-native, which means “the average yard does a poor job of supporting native flora and fauna,” says invasive plant expert Bethany Bradley at the University of Massachusetts Amherst.
She and her colleagues at UMass, at the Northeast Climate Adaptation Science Center (NE CASC) and elsewhere in New England and New York recently created an illustrated, downloadable pamphlet available free online for Northeast gardeners who want their yards and plantings to assist in increasing biodiversity and to avoid introducing potentially harmful invasive species.
Bradley and other members of the Northeast Regional Invasive Species and Climate Change (RISCC) Management Network point out that “by shifting our plantings towards natives, we can dramatically increase the diversity of bees, butterflies, birds and other animals. In contrast, non-native plants do not support local food webs and can become invasive.” Native plants not only increase biodiversity, they support resilient ecosystems in the face of expected climate changes, they add.
Bradley explains, “We thought, rather than helping a bunch of potentially invasive species adapt to climate change, why not focus on helping native species? So we curated a pamphlet that highlights some fantastic native species that support native wildlife and are adapted to the warmer climate conditions that climate change is bringing.” She is an associate professor of invasion ecology and biogeography in the environmental conservation department at UMass Amherst.
The tri-fold pamphlet, “Gardening with Climate-smart Garden Plants in the Northeast” includes definitions of terms such as invasive and non-native, plus a projection of the U.S. Department of Agriculture Hardiness Zones under climate change. They are based on minimum temperature and intended to help gardeners determine where plants can grow. The pamphlet defines climate-smart gardening as “planting for present and future conditions using native species adapted to both current and future hardiness zones.”
Among the benefits of using native plants are that they are associated with a 50% higher abundance of native birds, nine times higher abundance of rare birds, three times more butterfly species and double the abundance of native bees. Also, the authors state that native trees support twice the caterpillar diversity of related non-native trees.
They list five native grasses, 15 native flowering plants, 11 native shrubs, nine native trees plus hardiness information for each, as well as the conditions they prefer such as sun vs. shade and wet vs. dry. The benefits of each species to the environment and garden aesthetics are also presented, including edible or showy fruits, supporting birds and pollinators, deer resistance and low maintenance.
Co-author Toni Lyn Morelli, a research ecologist at the U.S. Geological Survey’s NE CASC, notes that this information comes just in time for spring gardening. “With movement restricted, there is a nice opportunity to turn to your yard or common space to cultivate nature,” she points out. “This guide not only highlights what are good species to plant but also which species in our backyards should be removed as they are causing ecological problems and taking up space that beneficial natives could occupy.”
The pamphlet features maps, graphs and photos of several prominent non-native invasive plants that escaped from gardens and have large environmental costs. ‘Status-quo’ gardening with non-natives increases the risk of introducing future escapees, the authors state. They report, for example, that non-native plants are 40 times more likely to become invasive than native garden plants, which can cost government and other environmental management organizations an estimated $20 billion per year to manage and control.
In addition to Bradley and Morelli, authors include other members of the RISCC Network at UMass, the USGS Northeast Climate Adaptation Science Center, Mt. Holyoke College and the New York Invasive Species Research Institute at Cornell University.