Washington - The lawn is the Atlas of our times, bearing its keepers and their children, dogs, cats and, if mine is any measure, whole armies of squirrels and chipmunks.
The lawn can bear this burden, with some periodic help, but it has also had to support a much tougher load - that of society's conflicting expectations.
Up and down the land, local ordinances enshrine the front yard as a place where neatly mown lawns framed with low or no fences could speak of a communal respectability, openness and uniformity. With suburbia came and remains an enforced neighbourliness. There was a time when every block had at least one greensward hobbyist, usually male, in unbridled pursuit of the trophy lawn. This mania probably has dissipated now that we inhabit Screen World.
To other eyes, the lawn is no trophy but a throwback to a time when its symbolic probity came at a cost not only to our individuality but to the health of the planet.
For a generation at least, environmentalists have been railing against the lawn for its addiction to scarce water, to polluting fertilisers and to life-killing pesticides.
My view? The lawn is a welcome feature in many (though not all) gardens, but as one considered element of a landscape. Cultivated with care and knowledge, the lawn is a net environmental asset in its ability to check storm water, filter pollutants and generally cool the heat island.
Others might not regard the turf as kindly, and the debate lingers, but the lawn itself has moved on: Better practices and improved grass varieties now enable greater success with this ubiquitous land form. That is the central message of a living exhibition, “Grass Roots,” that opened this month at the National Arboretum in Washington and will be around for a few years.
I asked the experts behind the exhibit, Scott Aker and Geoffrey Rinehart, to rattle off some of the most common lawn blunders. You may know them already, but they're worth repeating:
Mowing too short: If you mow cool-season grasses too short, you're inviting disaster. The grass will become stressed and die back, and the void will be filled with weeds. Keep your mower at its highest setting.
Poor drainage: Standing water will drown turf grass. Waterlogging is often associated with heavy clay soil and soil compaction. Before the exhibit was planted, crews had to build drains and add tons of compost. The exhibit also demonstrates what to do with ponding: Forget the lawn and create a rain garden that will receive and retain storm water. The gardeners here have planted the basins with Nebraska sedge, a species suited to flood and drought.
Too much shade: Most grass varieties will grow in light shade but prefer sunny sites. Varieties of fine fescues - shown in the display - will grow in shadier places but they are generally not as tough as sunny grass types. A common problem, Rinehart said, is that a lawn once in an open and sunny location is later shaded by mature trees, a situation hard to grasp because it is gradual. In full shade, replace the lawn with suitable ground covers.
The wrong grass: Perennial ryegrass and Kentucky bluegrass struggle in the heat and humidity of the mid-Atlantic. The latter is all right in mixes of up to 20 percent, and is used to tie together sod, but a lawn of bluegrass will, in time, have you singing the blues. In our area, the perennial ryegrass stand will sprout quickly, look lush and then after Memorial Day succumb to gray leaf spot. Rinehart has seeded an area to demonstrate.
Inferior seed: The dominant grass type here is turf-type tall fescue, but the key point - so often lost when we grab a bag from the mass merchandiser - is that certain varieties have been bred specifically for the difficult conditions of the mid-Atlantic. These varieties are more likely to survive stress and require less fertiliser and pesticide. The University of Maryland (www.mdturfcouncil.org/resources) and Virginia Tech (www.ext.vt.edu/topics/lawn-garden) have put together lists of superior varieties worth knowing before you buy seed or sod. (The labels list varieties.)
And what of warm-season grasses?
These stay green and attractively short in the heat of summer, push out any weeds and need fewer “inputs.” The big downside is that they spend November to April in a straw-brown state, if they survive the winter.
Visitors to “Grass Roots” will find swaths of southern grasses, of Bermuda, St. Augustine and centipede grass. They are not really hardy and should not be tried at home, not in the mid-Atlantic anyway although one Bermuda grass, a variety named Tifway 419 might survive a sheltered garden.
The one warm-season grass in common use here is zoysia, specifically a variety named Meyer. I have always disliked its winter browning and habit of spreading, but Rinehart heartily recommends a newer variety, Zenith. This darker green variety is finer, and its period of brownness is shorter. And forget seeds or that old-fashioned, laborious way of installing zoysia, with plugs. If you're going to take the plunge, install it as strips of sod, he says.
I should mention that the exhibit also shows how turf has been used on sports fields and golf courses, and features other dicots fundamental to agriculture, which is to say, feeding all of us. These include sweet corn, rice and various grains.
But if you're looking for a reason to fall in love with the lawn again, “Grass Roots” might do it.
“In the past, our love affair with the lawn was based on conformity and civic pride of keeping our communities looking a certain way,” said Aker. “That's changed. We are heading into a future that's much more fun, of people expressing themselves with their turf.”
Washington Post