Lawn

A typical lawn

A lawn sprinkler

A lawn is an area of land planted with grass, and sometimes clover and other plants, which are maintained at a low, even height.

Usage

Lawns are a standard or essential feature of ornamental private and public gardens and landscapes in much of the world today. Lawns are created for aesthetic use in gardens, and for recreational use, including sports. They are typically planted near homes, often as part of gardens, and are also used in other ornamental landscapes and gardens.

Lawns are also a common feature of public parks and other spaces. They form the playing surface for many outdoor sports, cutting erosion and dust as well as providing a cushion for players in sports such as football, cricket, baseball, golf, tennis and bocce. In sports venues, the term lawn is usually replaced by turf or green.

Several different species of grass are used, depending partly on the intended use of the lawn, with vigorous, coarse grasses used where active sports are played, and much finer, softer grasses on ornamental lawns, and partly on climate, with different grasses adapted to oceanic climates with cool summmers, and tropical and continental climates with hot summers.

Important cool summer grasses include species of Agrostis (bent), Festuca (fescue), Lolium (ryegrass; the most important sports grass), and Poa (meadow-grass or bluegrass). Important hot summer grasses include species of Cynodon (bermuda grass), Stenotaphrum secundatum (St. Augustine grass) and Zoysia (zoysia grass).

Lawns cover a significant area in the United States. In a recent NASA-sponsored study, researcher Christina Milesi estimated the area covered by lawns to be about 128,000 square kilometers (nearly 32 million acres) making it the largest irrigated crop in the United States, about three times that of irrigated corn. [1]

Lawncare is big business in America. Estimates of the amount spent on professional lawn care services vary, but a Harris Survey put the total at $28.9 billion in 2002, which calculates to roughly $1,200 per household, spread over the 24.7 million households who use such services.

Virginia Scott Jenkins, in her book The Lawn: A History of an American Obsession (1994), traces the desire to kill weeds historically. She notes that the current rage for a chemically-dependent lawn emerged after World War II, and argues that "American front lawns are a symbol of man's control of, or superiority over, his environment."

Approximately 50-70 percent of U.S. residential water is used for landscaping, most of it to water lawns.

Along with trees, lawns are a vital player in the fight against urban heat islanding. They provide oxygen conversion, filtering of air particulates, erosion control, air and surface cooling to offset miles of new asphalt, cement, and rooftops. In comparison to bare dirt, a lawn may be 20 degrees cooler on a hot day, and up to 40 degrees cooler than cement surfaces.

Maintenance, construction and management of lawns of various kinds are the focus of much of the modern horticulture industry.

Lawn Grass Zones of the U.S.

History

Before the invention of mowing machines in 1830, lawns were managed differently from today. Lawns belonging to wealthy people were sometimes maintained by the labour-intensive methods of scything and shearing. In most cases however, they were pasture land, maintained by grazing with sheep or other livestock. Areas of grass grazed regularly by rabbits, horses or sheep over a long period can form a very low, tight sward which is similar to a modern lawn. This was the original meaning of the word "lawn", and the term can still be found in place-names. Some forest areas where extensive grazing is practiced still have these semi-natural lawns. For example, in the New Forest, England, such grazed areas still occur commonly and are still called lawns, for example Balmer Lawn.

Lawns became popular in Europe from the Middle Ages onward. The early lawns were not always distinguishable from pasture fields. It is thought that the associations with pasture and the biblical connotations of this word made them attractive culturally. By contrast, they are little known or used in this form in other traditions of gardening. In addition, the damp climate of maritime Western Europe made them easier to grow and manage than in other lands. Lawns were also used in medieval times within monasteries and in the courtyards of castles for the lords and ladies to take their daily constitutional and escape from the odours of the castle.
It was not until the Tudor and Elizabethan times that the garden and the lawn became a place to be loved and admired. Created as walkways and for play areas, the lawns were not as we envisage them today. They were made up of meadow plants, such as camomile, a particular favourite. In the early 1600s, the Jacobean epoch of gardening began. It was during this period that the closely cut "English" lawn was born. By the end of this period, the English lawn was the envy of even the French. It was also seen as a symbol of status by the gentry. In the early 1700s, gardening fashion went through a further change. William Kent and the age of Capability Brown were in progress, and the open "English" style of parkland was seen across Britain and Ireland. Lawns seemed to flow from the garden into the outer landscape.
During Victorian times, as more plants were introduced into Britain, and the influence of France and Italy became prevalent, lawns became smaller as borders were created and filled with plants, statues, sculptures, terraces and water features, which started eating into the area covered by the lawn. In the United States, it was not until after the Civil War that lawns began to appear in middle class residences. Most people did not have the hired labor needed to cut a field of grass with scythes. Average homeowners either raised vegetables in their yards or left them alone. If weeds sprouted that was fine. Toward the end of the 19th century, suburbs appeared on the American scene, along with the sprinkler, greatly improved lawn mowers, new ideas about landscaping and a shorter work week.

Lawns do not have to be, and have not always been of grass. Other possible plants for fine lawns in the right conditions, are camomile and thyme. Some lawns, if grown in difficult conditions for grasses, become dominated by whatever weeds can survive there; these include clovers in dry conditions, and moss in damp shady conditions.

Maintenance

Closeup of droplets of water on blades of grass

Maintaining a rough lawn requires only occasional cutting with a suitable machine, or grazing by animals.

Higher quality lawns however require a number of operations. These may include:
* Mowing, to cut the grass regularly to an even height
* Scarifying and raking, to remove dead grass and prevent tufting
* Rolling, to encourage tillering (branching of grass plants), and to level the ground
* Top dressing the lawn with sand, soil or other material
* Spiking or aeration, to relieve compaction of the soil
* Watering, to prevent from going dormant and turning brown
* Fertilizing
* Pesticide application to manage weeds and pests

Criticisms

A number of criticisms of lawns are based on environmental grounds:
* Many lawns are composed of a single species of plant, or of very few species, which reduces biodiversity, especially if the lawn covers a large area. In addition, they may be composed primarily of plants not local to the area, which can further decrease local biodiversity.
* Lawns are sometimes cared for by using pesticides and other chemicals, which can be harmful to the environment if misused.
* Maintaining a green lawn often requires large amounts of water. This was not a problem in temperate England where the concept of the lawn originated, as natural rainfall was sufficient to maintain a lawn's health. However the exporting of the lawn ideal to more arid regions of the world, such as the U.S. Southwest, has crimped already scarce water resources in such areas, requiring larger, more environmentally invasive water supply systems. Grass typically goes dormant during cold, winter months, and turns brown during hot, dry summer months, thereby reducing its demand for water. Many property owners consider this "dead" appearance unacceptable and therefore increase watering during the summer months.
* In the United States lawn heights are generally maintained by gasoline powered lawnmowers, which contribute to urban smog during the summer months. The U.S. Environmental Protection Agency found that in some urban areas, up to 5% of smog was due to pre-1997 small gasoline engines such as are typically used on lawnmowers. Since 1997, the EPA has mandated emissions controls on newer engines in an effort to reduce smog. [2]
* Lawns use up vast areas of arable land that might otherwise be used for growing crops.

However, using ecological techniques, the impact of lawns can sometimes be reduced. Such methods include the use of local grasses, proper mowing techniques, leaving grass clippings in place, integrated pest management, organic fertilizers, and introducing a variety of plants to the lawn.

In addition to the environmental criticisms, some gardeners question the aesthetic value of lawns.

One positive benefit of a healthy lawn is that of a filter for contaminants and to prevent run-off and erosion of bare dirt. Highway construction projects in the United States now routinely include replanting grasses on disturbed soils for this purpose, although they are not maintained as lawns.

References

*Looking for Lawns - a general interest article about the NASA study
*Ted Steinberg, American Green, The Obsessive Quest for the Perfect Lawn, (2006) W.W. Norton & Co. ISBN 0393060845
*Virginia Scott Jenkins, The Lawn: A History of an American Obsession, (1994) Smithsonian Books. ISBN 1560984066
*Small Engine Emission Standards: FAQ for Dealers and Distributors - U.S. EPA (PDF format)

Lawn: Encyclopedia BETA

Contents