Lawn is typically an area of closely cut grass with a mostly uniform color and texture. Lawns are a familiar sight in many cities and suburbs. They provide a background setting for homes and household gardens. Lawns also form a major part of outdoor recreation areas and sports arenas. Large lawns are a dominant feature of many parks and public gardens. People use lawns as places to relax, as settings for informal sports matches, or as sites for huge outdoor concerts.
A lawn is actually a kind of ecosystem—a group of living things along with their environment and the relations among both. Lawn ecosystems are dominated by various kinds of grasses. Grass, unlike most other plants, grows from new shoots at or below the surface. Because of this, grasses can quickly regrow after cutting, grazing, or even burning. Lawn grasses require regular cutting to maintain a desirable height.
Types of lawns
People develop different kinds of lawns for various purposes. For example, different species (kinds) of grass have different qualities and maintenance requirements. People choose lawn grasses based on the local climate and soil conditions, as well as the way the grass looks.
Lawn grasses can be divided into two basic categories: cool weather grasses and warm weather grasses. Popular cool weather grasses include perennial ryegrass, fescue, and bentgrass. Kentucky bluegrass, also called smooth meadow grass, is especially popular in the northern United States. It can withstand cold winters and usually recovers quickly from damage. It is also widely used as a sports turf.
Warm weather grasses include Bahia grass, Bermuda grass, carpet grass, centipede grass, St. Augustine grass, and zoysia grass. Kikuyu grass, a durable species native to tropical Africa, is used in lawns throughout the world. But it is often considered a weed because it can grow quickly and can replace other plants.
People have developed different varieties of grass through breeding. Breeding is the careful selection of plants or other organisms to improve the usefulness of their offspring. For example, people have developed over 200 different varieties of Kentucky bluegrass. Some varieties are particularly well adapted to certain local soils and climate conditions. Other varieties are especially durable, and still others differ in color or texture.
Lawns developed for certain sports require especially thorough maintenance. Such sports include football, soccer, golf, and tennis. These sports are sometimes played on artificial turf, a manufactured product that looks like grass. Artificial turf requires less maintenance than natural grass and is not as easily damaged by hard use. But natural grass is generally softer and heats up less quickly in strong sunlight. Athletes have differing opinions on the advantages and disadvantages of artificial turf and natural grass.
Growing and maintaining a lawn
A lawn can be planted in one of two main ways: (1) growing the grass from seed, or (2) laying sod. In both cases, the soil must be carefully prepared for the best results. Once the grass takes root, every lawn requires some degree of maintenance.
Growing a lawn
from seed is often cheaper than laying sod. Planting seed can also result in a more durable lawn, because the young plants develop a more natural system of deep roots. Lawn growers can also create custom mixtures of seed that are suited to specific needs or environmental conditions. But growing a lawn from seed takes more time than laying sod. It also requires careful watering and weeding.
Sod consists of pieces of grassy turf, usually purchased from a commercial nursery. Lawn growers lay this turf on the bare soil, and the grass takes root. Laying sod is more expensive than growing a lawn from seed, and the root systems may not be as strong. But laying sod provides rapid results and requires less intensive maintenance in the early stages of growing.
Maintenance
of an established lawn requires regular cutting. Each kind of grass works best when cut to a particular height. In addition, many lawns require regular watering, depending on the local climate and the variety of grass. Some lawns require fertilizers to help the grass grow.
Many kinds of pests and weeds threaten lawns. Lawn owners may apply chemical pesticides, herbicides, and fungicides to a lawn to kill insects, weeds, and fungi. Lawn owners may also simply pull up weeds that grow on lawns. Some lawns require raking to remove dead grass shoots and to encourage the growth of new ones.
Lawns and the environment
Lawns have important environmental benefits compared to bare soil, artificial turf, or such hard surfaces as concrete or gravel. For example, lawns help filter and retain water and prevent the erosion (wearing away) of soil. Lawns also have a cooling effect, especially in urban areas.
However, lawns can also have undesirable effects on the environment. Lawns consist of only a few species of grass and support only certain animals and other living things, reducing species diversity. In addition, most lawn grasses are not native to the areas in which they are grown. As a result, they are often not adapted to the local climate and so require regular maintenance to keep healthy. This maintenance can have a substantial impact on the environment.
Many lawns require regular watering, which can strain water supplies. In some parts of the United States, for example, more than half of residential water use occurs outdoors. Most of this water is used to water lawns. Pesticides, herbicides, fungicides, and fertilizers applied to lawns can seep into water sources, creating environmental problems.
Gasoline-powered lawnmowers and other equipment widely used to maintain lawns consume large amounts of energy, and their engines are often inefficient. They also give off harmful exhaust. In urban areas during the summer, exhaust from such lawn equipment can significantly contribute to smog, a type of air pollution.
Some communities place limits on certain lawn care activities to help reduce their harmful impact on the environment. Where water is scarce, for example, the government may place restrictions on the use of lawn sprinkler systems. Some communities prohibit using lawnmowers with certain kinds of engines.
Some people help their lawn grow using grass clippings or compost (partially decayed plant material), rather than chemical fertilizers. Other people grow different, less traditional kinds of “lawns,” such as meadows or vegetable gardens. If grown with plants native to the area, such lawns require less maintenance and are less harmful to the environment than traditional lawns. Electric-powered or manually-powered lawn equipment uses less energy and creates less pollution than gasoline-powered machines.
History
Lawns developed from such natural grassy habitats as heaths, meadows, and pastures. In these areas, the growth of the grass was kept in check by grazing animals, or sometimes by natural fires. Many plants considered weeds in lawns once grew naturally in such habitats. Such plants include chickweed, dandelion, mosses, and plantains.
Lawns had become a popular feature in some European gardens by the early 1700’s. Early lawns served as a symbol of status because they required grazing animals or laborers to cut the grass. For centuries, only the upper class could afford such luxuries.
Lawns became more widespread after the invention of mowing machines and lawnmowers in the 1800’s. People converted vast new areas to lawns in the 1900’s as they developed suburbs and gained more leisure time. Today, millions of acres or hectares are covered by lawns, and people spend billions of dollars each year growing and maintaining their lawns.
