You are currently viewing The Problem With Lawns

By Cynthia B. Lauer, Master Gardener, SCMG

Lush, green lawns are a dominant landscaping feature. The standard blend of Kentucky bluegrass, fescues, and perennial rye grass serves as an outdoor carpet whether in an urban backyard or a large public park. It beckons people to picnic on it, kids to play on it, and dogs to run on it. The lawn typically foregrounds mixed perennial beds and serves as the essential landscaping feature of a home.

While undeniably walkable, turfgrass comes with a long list of concerns:

  • Lawns require irrigation, mowing, fertilizing, weeding, aerating, de-thatching, re-seeding and top-dressing to look their best. For those starting with sod, a topsoil depth of 15–20 cm is needed. Considerable time, labour, and cash are necessary to optimize the appearance of a nice lawn
  • Grooming a lawn requires machinery powered by fossil fuels. The Princeton Student Climate Initiative found that a four-stroke lawnmower operating for one hour burns the same amount of fuel as a vehicle traveling for five hundred miles. The two-stroke engines of many leaf-blowers pose a unique environmental hazard because they do not have an independent lubricant system; they mix oil and fuel. Since about 30% of the fuel does not combust completely, these engines release toxic gases into the air, which contribute to rising carbon dioxide emissions
  • To attain lush, fertile, green lawns, homeowners use millions of tons of nitrogen-based fertilizers every year. David Wolfe, a professor of plant and soil ecology at Cornell University, notes that for every ton of nitrogen in fertilizer, four or five tons of carbon are added to the atmosphere. A full 40–60% of nitrogen from fertilizers runs off into surface and groundwater, contributing to the problem of contaminated runoff after extreme weather events
  • During times of drought, turf grass will need supplemental watering to ensure that moisture penetrates the soil to a depth of 4 inches. Millions of gallons of drinking water are used for lawns every growing season. The unsustainable risks range from a depletion of water aquifers to the devastation of local ecosystems.
  • In Canada, turfgrass species are cool-season plants that enter a natural dormant period in the middle of summer. As they brown out, they lose their appeal. This is just one reason why homeowners renovate their lawn. Other reasons include poor fertilization, shallow soil, inadequate drainage, and damage from foot traffic, weed invasion, excessive shade, dog urine, compaction, or drought. Turf is also vulnerable to insects such as chinch bug, sod webworms, white grub larvae, and crane fly larvae. Coaxing maximum performance from a lawn all season long requires a constant attention to these chronic threats

Besides these problems with lawns, there is the simple fact that turf contributes nothing to the ecosystem. A perfect lawn provides no food for animals or insects, no place for breeding species to go, and nothing that can serve as overwintering habitat. The vast expanses of land dedicated to turfgrass is maintained at the expense of countless native plants whose environmental value is indispensable. Through evolution with native animals and insects, native plants have developed networks of mutual dependencies with these species. Birds are also affected. As celebrated environmentalist, Doug Tallamy, has shown the vast majority of North America’s native bird species rear their young on insects. In turn, insects depend on native plants for foraging and habitat. The failure of lawns to support insect life has a direct and significant impact on bird life.

Lawns exist to satisfy people. They do nothing for other species.

Growing sensitivity to these concerns are leading gardeners toward lawn alternatives. Despite their popularity, the best choice to make is not non-native clovers, thyme, or chamomile, and not notoriously invasive groundcovers such as English ivy, periwinkle, and lily-of-the-valley.

Fortunately, native groundcovers are numerous in variety and clearly beneficial. They are increasingly available in brick-and-mortar nurseries and online.

Attractive, sustainable, and cost-effective, native plants not only solve the multiple problems of maintaining turfgrass, but they also make a significant contribution to the environment by supporting native bees, butterflies, and other insects. Native plants provide foraging for adult insects and sustenance for their entire reproductive cycle. They serve as habitat for nesting and overwintering for insects, birds, and mammals.

Well-planned native plant gardens are not only drought-resistant and need no fertilizer, but support deeper root systems that increase stormwater filtration and water quality and reduce runoff. They eliminate the need for fertilizers, insecticides, and herbicides. And they reduce greenhouse gas emissions by eliminating the use of lawnmowers and leaf blowers powered by fossil fuels.

Here are a few suggestions for native groundcovers. Silverweed, field pussytoes, moss phlox, violets, and Canada anemone enjoy full sun to part-sun, while wild ginger, Virginia waterleaf, native ferns, foamflower, and mayapple thrive in part shade and sometimes full shade. Barren strawberry, wild strawberry, and wild geranium are easy to grow in most conditions. For gardeners who admire the look of turf, some of the native sedges will work nicely.

Wild Strawberry (Fragaria virginiana)
Credit: Sharon and Wayne Brandt
 
Wild Ginger (Asarum canadense)

Credit: David J. Stang, CC BY-SA 4.0

Silverweed Cinquefoil (Argentina anserina)
Credit: Sharon and Wayne Brandt
 
Common Blue Violet (Viola sororia)

Credit: Bernt Fransson, CC BY-SA 4.0

Among the dozens of possibilities in native groundcovers, there are sure to be some that satisfy every gardener’s desire.