By Andrew Bunting, PHS VP of Horticulture
At the recent Perennial Plant Conference at Swarthmore College, horticulture and gardening experts Owen Worser and Summer Rayne Oakes both advocated for turning lawns into more naturalistic plantings.
Wormser outlined the environmental issues with lawns. Lawns have a massive carbon footprint, producing four times more carbon than they absorb. The American lawn is the largest irrigated crop in the United States -- requiring more irrigation than corn or soybeans. Homeowners use ten times more chemicals per square acre than farmers, and these chemicals often poison the soil and cause serious impacts to pollinators and feeding birds.
Converting a lawn to a garden bed, pollinator garden, or meadow planting does not have to be a major undertaking. If every homeowner could aspire to convert 10% of their lawn over time, this positive impact on the environment would be monumental. By comparison, a lawn converted to a planting bed is considerably less maintenance. It requires very little water and no fertilizer, herbicides, fungicides, or insecticides. They support habitats for birds, butterflies, bees, moths, and a host of other native species.
There are many different design approaches to consider, but a simple rule of thumb is to plant 50% grasses and 50% flowering perennials. The grasses might include side oats gramma, Bouteloua curtipendula; switch grass, Panicum virgatum; prairie dropseed, Sporobolus heterolepis; little bluestem, Schizachyrium scoparium; big bluestem, Andropogon gerardii; and purple love grass, Eragrostis spectabilis.
There are many, many flowering perennials to choose from. The following are great ornamental plants, but also some of the very best of the perennials for pollinators, including: anise hyssop, Agastache foeniculum; butterfly milkweed, Asclepias tuberosa; purple coneflower, Echinacea purpurea; pale coneflower, Echinacea pallida; rattlesnake master, Eryngium yuccifolium; beebalm, Monarda didyma; beardtongue, Penstemon digitalis; mountain mint, Pycnanthemum muticum; smooth blue aster, Symphyotrichum laeve; showy goldenrod, Solidago speciosa; and blue sage, Salvia azurea.
While many pollinators are generalists -- meaning they can visit many types of pollinator plants -- there are a host of specialist bees that need specific plants. Some of these plants include Chrysopsis mariana, Erythronium americanum, Geranium maculatum, Heliopsis helianthoides, Heuchera americana, and Rudbeckia laciniata.
There are several approaches to take when reducing the lawn on your property. One of the easiest approaches is to simply widen your garden beds. You can expand them to the lawn side of your property -- from there, either new plants can be purchased to add to this new garden bed space, or you might also simply divide your existing perennials to create new plants. Also, a quick assessment of your lawn will undoubtedly highlight many unused parts of your yard. For example, often where pathways converge or where a walkway converges with the driveway, there are triangular-shaped areas that are simply unusable lawn or recreation spaces. When these areas are converted to garden beds, they also inevitably create great “pockets” of ornamental gardens. This approach can be done over time so as not to make the transformation too burdensome economically or otherwise.
While most of the aforementioned plants are sun-loving, lawn conversion can also occur in parts of the yard that are shady or too wet -- in fact, often these areas have difficulty sustaining an attractive lawn in the first place. Many great ornamental plants can withstand poorly drained soil, including standing water. A few great shrubs should be considered including the Virginia sweetspire, Itea virginica ‘Henry’s Garnet’; buttonbush, Cephalanthus occidentalis; summersweet, Clethra alnifolia ‘Ruby Spice’ and ‘Hummingbird’ and the several selections of winterberry, Ilex verticillata, including ‘Winter Red’, ‘Winter Gold’ and ‘Maryland Beauty’. For good fruit production you will need a male pollinator such as ‘Southern Gentleman’.
There, too, are many outstanding perennials that can withstand moist conditions including, Joe-pye weed, Eutrochium dubium; turtlehead, Chelone glabra; butterfly milkweed, Asclepias incarnata; two cardinal flowers, Lobelia cardinalis and Lobelia siphilitica; royal fern, Osmunda regalis; sensitive fern, Onoclea sensibilis and two native iris, Iris prismatica and Iris versicolor.
In addition to creating ornamental beauty and ecological habitats on your property, there will be the additional benefit of reduced mowing, resulting in the need to purchase and consume fossil fuels, resulting in less pollution.