TENNESSEE TURFGRASS: Jay McCurdy Ph.D., Associate Professor, Turfgrass Extension Specialist, Department of Plant & Soil Sciences, Mississippi State University
This is the first article of a multi-part series detailing the origins and future of turfgrass.
Turf consists of a layer of various plants cultivated to form a uniform ground cover, typically one that can tolerate foot traffic and routine mowing. The first known use of the word turf occurs before the 12th century and refers to the “upper stratum of soil bound by grass” (Merriam-Webster, 2022). Objectively, turf only exists in human-maintained systems; however, the species comprising various turf scenarios long predate human interference.
Those turfgrass species most frequently selected for turf scenarios have been subject to environmental pressures (notably, frequent grazing) that have selected for traits that enhance their value as turfgrasses. Valuable traits include color, texture, uniformity, growth habit, and durability under stress. Plant breeding, the introduction of non-native and exotic species, and recurrent selection for desirable traits have led to modern cultivars and varieties of turfgrass that predominate in maintained turf settings such as lawns, sports fields, golf courses, sod farms, and roadside rights-of-way.
Turfgrasses are typically narrow-leaved species of relatively short stature that are somewhat regularly mown at heights of approximately four inches or less (Thompson and Kao-Kniffin, 2017). By convention, all grasses, including turfgrasses, belong to the Poaceae family of monocotyledonous flowering plants. The monocotyledonous (monocot) clade includes grasses and grass-like flowering plants with seeds that contain only one embryonic leaf (also known as a “cotyledon”). Monocots offer few obvious advantages for turf applications, as other flowering plants in the dicotyledonous clade (having two embryonic leaves) also persist under typical mowing heights as weeds or amenity forbs within various turf scenarios.
Not Just Grass
Turfgrasses are broadly classified as cool- or warm-season plants. Cool-season species are the predominant turfgrass species in climates with cold winters and mild summers, as well as adequate soil moisture. Warm-season species predominate in climates with mild winters and hot summers. The overlapping area between the two is termed the transition zone, where cool- and warm-season species grow equally successfully.
Cool-season species have evolved a C3 photosynthetic pathway for carbon fixation. They use an enzyme (called RuBisCO) to fix CO2. That carbon from CO2 forms a three-carbon sugar and then goes on to fuel plant growth and metabolism. Alternatively, warm-season species have evolved a C4 photosynthetic pathway that produces a four-carbon sugar. Plants with the C4 pathway have improved metabolism and a competitive advantage over C3 plants under conditions of drought, high temperatures, and limited nitrogen or CO2.
Cool- and warm-season species have different optimal temperatures for growth and metabolism. Warm-season species grow best when temperatures are above approximately 80°F and enter dormancy below their “base growth temperature” of around 50°F. Alternatively, cool-season species grow best when temperatures range from 60–75°F. Cool-season species enter a state of winter dormancy at temperatures below freezing and are often considered dormant during summer conditions that exceed their ideal growing temperatures, especially when soil moisture is limited. Growth models to predict the suitability and phenology of these species are largely based upon these parameters and estimates.
There are approximately 40 million acres of turfgrass in the United States (2% of the total U.S. land cover) (Milesi et al. 2005). Several estimates suggest that residential lawns represent roughly 75% of U.S. cultivated turf (an area of approximately 30 million acres) (Roberts and Roberts, 1987; Vinlove and Torla, 1994).
A lawn is an area of soil-covered land planted with grasses or forbs that are maintained at a short height by mowing or grazing. Lawns may be situated in residential areas or commercial or shared public spaces. The word lawn originates from an ancient Celtic language, possibly Welsh. The Welsh word llan (pronounced ɬan, where ɬ has a slight sh sound), which is often used in compound words to describe a local place named for a saint, such as Llanbedr or St. Peter, has come to mean a cleared or enclosed area of land—perhaps around a church, business, or settlement. The common Brittonic word llan or laun came to mean an enclosure, most likely around a place of worship. Early lawns would have been used for communal gatherings and possibly grazing, although the area would have been distinct from agricultural fields. Lawns would have been composed of mixed grasses and forbs that were endemic to the area.
Lawns are frequently attributed to European origins, but their purposes (e.g., communal gatherings, periodic grazing, aesthetics, etc.) and the ingredients to manage them (low-growing species and a suitable environment) have often coincided throughout global human history. For at least many thousands of years, humans have felled trees, grazed, and gardened their immediate surroundings. This behavior partly arose from the advent of agriculture, but also serves for defense—modern gardeners can easily relate to the struggle to keep deer or rabbits from ravaging gardens. An aesthetic preference for stately grounds certainly would have developed, but could only occur when safety, time, and labor were available. Grazing would have prevented cleared land from reverting to forest, and other, previously intangible benefits of a cultivated lawn would have been noticed.
Though they may not fit neatly within the contemporary definition of a lawn, early examples of maintained open spaces as “yards” or “lawns” are fairly commonplace the world over. They include examples like the plaza between mounds at the Cahokia complex in Illinois, where the stick-and-ball sport chunkey
was played 900 years ago, and Japanese gardens that incorporated manicured grasses, mosses, and even trimmed bamboo. While not unique to Europe, most scholars agree that the modern American lawn aesthetic owes much to European origins.
Lawns existed in Europe from the Middle Ages (in the 5th through the 15th century) onward. They were rudimentary by contemporary standards, with very practical purposes—line-of-sight for defense and communication, ease of movement, production of grain crops and vegetables, grazing, and fire prevention. Those early lawns must also have created vistas and an aesthetic that evolved with European civilization.
The European lawn of the 17th and 18th centuries was a demonstration of wealth and power at some of the continent’s finest estates. The palace of Versailles’s tapis vert or green carpet—one of Europe’s first and finest garden lawns—was expanded by André Le Nôtre to two acres in the 1660s. A century later, the lawn had been cemented as an exemplar of Western Europe’s idealized built landscape. The architect Capability Brown refined the English lawn with natural or “romantic” estate settings for wealthy clientele. His landscapes featured smooth, undulating lawns running from “house to horizon,” sometimes with dammed rivers or creeks, serpentine lakes, clumps of vegetation and scatterings of trees, and a visible horizon line. These gardens often used grazed grass lawns or pastures to supplement the perception of scale within the landscape. In some instances, they used lines and texture to deceive the eye—employing concepts like false horizons using “ha-ha walls” or cleared land that sloped uphill and decreased in width as it reached a ridge.
During the late 18th century, wealthy families of the Americas began maintaining lawns. In 1780, a Shaker community near Philadelphia began commercializing lawn seed. Thomas Jefferson is credited with the first English-style garden in the United States, circa 1806.
Mowing Leads to Modern Lawns
Before the advent of mechanical mowers, manicured turfgrass required animal grazing or human-powered scythes. The term “mower” dates to the 14th century, referring to one who cuts grass with a scythe. The term may have multiple origins—Old English mawan and the Greek term amao both mean “to reap a crop.” In 1830, Edward Beard Budding based his mowing machine on a cloth-cutting cylinder used to trim the irregular nap of wool cloth. Thus, modern mowing equipment was born.
The Victorian era’s penchant for sport spurred revolutionary new mower designs to maintain sporting venues for golf, football, lawn bowls, lawn tennis, and cricket. In fact, the term “lawn-tennis” was coined in the 1880s.
Mowing is the most common practice performed on maintained turfgrass and is by most accounts the most important and defining maintenance operation. The obvious purpose of mowing is to reduce the height of the turf, but it also serves other purposes, including the control of undesirable vegetation (i.e., weeds) and the production of a desirable sports surface (e.g., a “true” putting surface or a target surface firmness).
The ability to mow large areas without tending livestock or toiling over a scythe revolutionized the grounds maintenance industry and sparked a revolution in landscape design. Modern lawns look far different from their early predecessors. Lawns have been a mainstay of the U.S. built environment since the mid-20th century, during which large tracts of land were converted into suburban housing, recreational areas, and commercial real estate. This trend, spurred by population growth, technological advancements, and other socioeconomic factors, led to a reliance on turfgrass as a ground cover for newly constructed outdoor spaces.
This is to say almost nothing of the parallel and synergistic developments of the golf industry, which we will explore in a future article. It also says little about the historical changes in schools of thought regarding urban infrastructure and the development of parks and neighborhoods that were spurred by successive waves of soldiers returning from overseas wars, the effects of the Spanish flu pandemic and city dwellers’ migration to the suburbs, or Depression-era spending on public projects that transformed the U.S. landscape and natural spaces in ways that are evident to this day.
In a future article, we will explore the concepts of landscape sustainability and “future-proofing” for the modern turfgrass economy. In much of the U.S. and around the world, rooftops, parking lots, busy city streets, and home lawns are replacing natural habitats. These systems have, for better and worse, changed how we interact with, build, and perceive our environment. Turf is just one result of these changes.
Merriam-Webster. (n.d.). Turf. In Merriam-Webster.com dictionary. Retrieved June 27, 2022, from https://www.merriam-webster.com/dictionary/turf
Milesi, C., Running, S.W., Elvidge, C.D., Dietz, J.B., Tuttle, B.T., & Nemani, R.R. (2005). Mapping and modeling the biogeochemical cycling of turf grasses in the United States. Environmental Management. 36(3), 426-38.
Roberts, E.C., and Roberts, B.C. (1987). Lawn and Sports Turf Benefits. Pleasant Hill, TN: The Lawn Institute. 31.
Thompson, G. L., & Kao-Kniffin, J. (2017). Applying biodiversity and ecosystem function theory to turfgrass management. Crop Science, 57(S1), S-238.
Vinlove, F. K., & Torla, R. F. (1994). Comparative estimations of US home lawn area. Journal of Turfgrass Management, 1(1), 83-97.READ THE ISSUE