For a generation now, lawns have been landscape villains to environmentally inclined gardeners. True, lawns provide an attractive setting for flower beds and shrubbery, and a traffic-tolerant play space for children and adults. But traditional turf does have serious drawbacks. To be maintained in good condition it demands huge inputs of labor, fertilizers, pesticides and water. This makes it a a significant source of greenhouse gases and air and water pollution. What’s more, it’s a green desert, providing little habitat and food sources for pollinators and other wildlife.
What if, though, these liabilities could be eliminated, and lawns could be made ecological contributors? That’s the challenge Dr. Eric Watkins of the University of Minnesota has been addressing with his research for more than a decade. He’s been experimenting with different types of grasses that can provide a conventional carpet of clipped greensward at a cost of far less resources and less work, while also permitting a more diverse habitat.
Dr. Watkins’ special focus has been a group of grasses, the fine fescues, which are traditional elements of “shady” seed mixes. They actually perform well in full sun, too. This group includes a number of species, such as hard fescue (Festuca longifolia), creeping red fescue (F. rubra), chewings fescue (F. rubra subsp. commutata) and sheep fescue (F. ovina). As the name fine fescue suggests, these grasses have thinner leaf blades than the more familiar Kentucky bluegrass and a less rich green color.
However, a fine fescue mix (Dr. Watkins likes to increase the genetic diversity of his lawns by blending the different species) flourishes typically with just a quarter to a half of the fertilizer a Kentucky bluegrass lawn would demand on the same site. Naturally drought tolerant, the fine fescues require irrigation only during prolonged periods of dry weather. Perhaps their most attractive feature from the gardener’s perspective is that they are slow-growing and naturally compact, requiring far less mowing. Indeed, if you can tolerate a somewhat tousled appearance, you can limit mowing to just twice a year, once in late spring and again in late summer.
Like any grass, fine fescues do not flourish everywhere. They are best adapted to temperate regions and do not thrive in the Deep South and Gulf Coast regions. Likewise, they struggle in areas where intense summer heat and drought are a regular feature. Nor do they grow well on chronically wet sites; fine fescues need a well-drained soil. Within these constraints, however, they are remarkably adaptable.
Another distinctive feature of these grasses is that, unlike Kentucky bluegrass, they are clump forming. That is, the fine fescues grow as individual plants, although as they establish themselves, these do expand to present the appearance of a continuous carpet. If planted less densely, however, the fine fescues can be interspersed with other low-growing, mower-tolerant plants. By mixing white clover (Trifolium repens), creeping thyme (Thymus praecox subsp. arcticus) and self-heal (Prunella vulgaris subsp. lanceolata) into a lawn, Dr. Watkins has greatly increased its attractiveness to a diversity of pollinators; University of Minnesota researchers have found over 50 species of native bees visiting such “bee lawns.”
Bee lawns provide a number of other environmental benefits besides their reduced need for fertilizer, water and mowing. To foster the wildflowers these lawns contain and the pollinators they attract, the gardener must avoid applications of broadleaf weed killers and most insecticides. The latter are rarely necessary, anyway, if the gardener plants fine fescue seeds that have been inoculated with endophytes, a beneficial fungus that lives inside the grass, providing resistance to many turf diseases and the insects that feed on the above-ground parts of the plant.
The state of Minnesota’s Board of Water and Soil Resources has begun to actively promote such pollinator-friendly lawns with its “Lawns to Legumes” program. The board provides very complete instructions about how to convert a conventional lawn, and it has joined the Blue Thumb partnership in awarding grants to gardeners to transform their turf.
For more information about bee lawns and low-input turf, listen to my conversation with Dr. Watkins on the Berkshire Botanical Garden’s Growing Greener podcast.