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Lawn

2007 Schools Wikipedia Selection. Related subjects: Recreation

   A typical lawn
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   A typical lawn
   A lawn sprinkler
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   A lawn sprinkler
   A striped lawn
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   A striped lawn

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

Usage

   Lawns are a standard 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 frequently a feature of public parks and other spaces. They
   form the playing surface for many outdoor sports, reducing 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 word lawn is often replaced by turf or green.

   Many different species of grass are used, often depending 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 summers, and tropical and continental climates with
   hot summers. It is also not uncommon to mix grass seeds. A 50/50
   mixture of grass types can, for example, form a stronger lawn when one
   grass type does better in the warmer seasons and the other is more
   resistant to colder weather.

Types of Lawngrass

   There are thousands of varieties of lawngrass, each adapted to specific
   conditions of precipitation, temperature, and sun/shade tolerance.
   Breeders are constantly creating new and improved varieties of the base
   list of lawngrass species. The two basic categories are cool season
   grasses and warm season grasses.

   Cool season grasses start growth at 5 °C, and grow at their fastest
   rate when temperatures are between 10-25 °C (Huxley 1992), in climates
   that have relatively mild/cool summers, with two periods of rapid
   growth in the spring and fall. They retain their colour well in extreme
   cold and typicaly grow very dense, carpetlike lawns with relatively
   little thatch.
     * Bluegrasses
     * Bent grasses
     * Ryegrasses
     * Fescues
     * Buffalo grass
     * Grama grass

   Warm season grasses only start growth at temperatures above 10 °C, and
   grow fastest when temperatures are between 25 °C and 35 °C, with one
   long growth period over the spring and summer (Huxley 1992). They often
   go dormant in cooler months, turning shades of tan or brown. Many warm
   season grasses are quite drought tolerant, and can handle very high
   summer temperatures, although temperatures below -15 °C can kill most
   warm season grasses.
     * Zoysia grasses
     * Bermuda grasses
     * St. Augustine grass
     * Bahia grass
     * Centipede grass
     * Carpet grass

United States

   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.

   Lawn care is thus a major business in America. Maintenance,
   construction and management of lawns of various kinds are the focus of
   much of the modern horticulture industry. 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 averages to around $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 element in the fight against urban
   heat islanding. Lawns provide:
     * Oxygen conversion,
     * Filtering of air particulates,
     * Erosion control,
     * Air and surface cooling to offset 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.
   Lawn Grass Zones of the U.S.
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   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 home owners 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
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   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

Seasonal Lawn Maintenance

   Seasonal lawn care will vary to some extent depending on the climate
   zone and type of grass that is grown, whether cool season or warm
   season varieties. In general, however, there are recognized steps in
   lawn care that should be observed in any of these areas.

   Spring or early summer is the time to seed, sod, or sprig your yard,
   when the ground is warmer. For a new lawn, it’s a good idea to add a
   fresh load of topsoil to the ground. Seeding the lawn is the least
   expensive way to plant, but it takes longer for the lawn to grow.
   Sodding is more expensive, but it will give you an almost instant lawn
   that can be planted in most climate zones in any season. Hydroseeding
   is a relatively quick and inexpensive method of planting. A
   nitrogen-based, slow-release fertilizer should be applied as well as a
   weed killer and a product for lawn pest removal.

   Summer lawn care requires raising the lawn mower if you have cool
   season grass and lowering it for warm season lawns. Lawns will require
   longer and more frequent watering, best done in early morning to
   encourage a stronger root system. This is also time to apply an
   all-purpose product such as Munns Golf Course Green Organic fertilizer.
   During the hot summer months, lawns may be susceptible to fungus
   disease. It’s advisable to take a sample to your local landscape expert
   for testing and treating your yard, if necessary.

   In the fall, lawns can be mowed at a lower height and thatch buildup
   that occurs in warm season grasses should be removed, although lawn
   experts are divided in their opinions on this. This is also a good time
   to add a sandy loam and apply fertilizer such as Munns Greenup, one
   that contains some type of wetting agent. Cool season lawns can be
   planted in autumn if there is adequate rainfall.

   Lawn care in winter is minimal, requiring only light feedings of
   organic material, such as green-waste compost, and minerals to
   encourage earthworms and beneficial microbes. Nitrogen-based
   fertilizers should not be applied during the months from November to
   March, because they will stimulate unwanted growth and contribute to
   disease and other lawn problems in the spring.

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. Grass can
       also recover quite well from a drought.
     * 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.
     * 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.

   Retrieved from " http://en.wikipedia.org/wiki/Lawn"
   This reference article is mainly selected from the English Wikipedia
   with only minor checks and changes (see www.wikipedia.org for details
   of authors and sources) and is available under the GNU Free
   Documentation License. See also our Disclaimer.
