Native Plants in Summerlin Landscaping: Why Use Them?

Landscape architecture is the design of outdoor areas, landmarks, and structures to achieve environmental, social-behavioural, or aesthetic outcomes.^[2] It involves the systematic design and general engineering of various structures for construction and human use, investigation of existing social, ecological, and soil conditions and processes in the landscape, and the design of other interventions that will produce desired outcomes.

The scope of the profession is broad and can be subdivided into several sub-categories including professional or licensed landscape architects who are regulated by governmental agencies and possess the expertise to design a wide range of structures and landforms for human use; landscape design which is not a licensed profession; site planning; stormwater management; erosion control; environmental restoration; public realm, parks, recreation and urban planning; visual resource management; green infrastructure planning and provision; and private estate and residence landscape master planning and design; all at varying scales of design, planning and management. A practitioner in the profession of landscape architecture may be called a landscape architect; however, in jurisdictions where professional licenses are required it is often only those who possess a landscape architect license who can be called a landscape architect.

A canal design focused on esthetical landscape architecture in Stockholm, Sweden.

A river with concrete walls like those of a flood control channel, a historic flood-control measure using landscape engineering in Houston, Texas. Such channelling, intended to be strictly functional, may make flooding worse, by speeding the flow instead of spreading the pulse of floodwater.^[3][4][5]

Modern landscape architecture is a multi-disciplinary field, incorporating aspects of urban design, architecture, geography, ecology, civil engineering, structural engineering, horticulture, environmental psychology, industrial design, soil sciences, botany, and fine arts. The activities of a landscape architect can range from the creation of public parks and parkways to site planning for campuses and corporate office parks; from the design of residential estates to the design of civil infrastructure; and from the management of large wilderness areas to reclamation of degraded landscapes such as mines or landfills. Landscape architects work on structures and external spaces in the landscape aspect of the design – large or small, urban, suburban and rural, and with "hard" (built) and "soft" (planted) materials, while integrating ecological sustainability.

The most valuable contribution can be made at the first stage of a project to generate ideas with technical understanding and creative flair for the design, organization, and use of spaces. The landscape architect can conceive the overall concept and prepare the master plan, from which detailed design drawings and technical specifications are prepared. They can also review proposals to authorize and supervise contracts for the construction work. Other skills include preparing design impact assessments, conducting environmental assessments and audits, and serving as an expert witness at inquiries on land use issues. The majority of their time will most likely be spent inside an office building designing and preparing models for clients.^{[citation needed]}

For the period before 1800, the history of landscape gardening (later called landscape architecture) is largely that of master planning and garden design for manor houses, palaces and royal properties. An example is the extensive work by André Le Nôtre for King Louis XIV of France on the Gardens of Versailles. The first person to write of making a landscape was Joseph Addison in 1712. The term landscape architecture was invented by Gilbert Laing Meason in 1828, and John Claudius Loudon (1783–1843) was instrumental in the adoption of the term landscape architecture by the modern profession. He took up the term from Meason and gave it publicity in his Encyclopedias and in his 1840 book on the Landscape Gardening and Landscape Architecture of the Late Humphry Repton.^[6]

John Claudius Loudon was an established and influential horticultural journalist and Scottish landscape architect whose writings were instrumental in shaping Victorian taste in gardens, public parks, and architecture.^[7] In the Landscape Gardening and Landscape Architecture of the Late Humphry Repton, Loudon describes two distinct styles of landscape gardening existing at the beginning of the 19th century: geometric and natural.^[6] Loudon wrote that each style reflected a different stage of society. The geometric style was “most striking and pleasing,” displaying wealth and taste in an “early state of society” and in “countries where the general scenery was wild, irregular, and natural, and man, comparatively, uncultivated and unrefined.”^[6] The natural style was used in “modern times” and in countries where “society is in a higher state of cultivation," displaying wealth and taste through the sacrifice of profitable lands to make room for such designs. ^[6]

The prominent English landscape designer Humphry Repton (1752-1818) echoed similar ideas in his work and design ideas. In his writings on the use of delineated spaces (e.g. courtyards, terrace walls, fences), Repton states that while the motive for defense no longer exists, the features are still useful in separating "the gardens, which belong to man, and the forest, or desert, which belongs to the wild denizens."^[6] Repton refers to Indigenous peoples as "uncivilized human beings, against whom some decided line of defense was absolutely necessary.”^[6]

The practice of landscape architecture spread from the Old to the New World. The term "landscape architect" was used as a professional title by Frederick Law Olmsted in the United States in 1863^{[citation needed]} and Andrew Jackson Downing, another early American landscape designer, was editor of The Horticulturist magazine (1846–52). In 1841 his first book, A Treatise on the Theory and Practice of Landscape Gardening, Adapted to North America, was published to a great success; it was the first book of its kind published in the United States.^[8] During the latter 19th century, the term landscape architect began to be used by professional landscapes designers, and was firmly established after Frederick Law Olmsted Jr. and Beatrix Jones (later Farrand) with others founded the American Society of Landscape Architects (ASLA) in 1899. IFLA was founded at Cambridge, England, in 1948 with Sir Geoffrey Jellicoe as its first president, representing 15 countries from Europe and North America. Later, in 1978, IFLA's Headquarters were established in Versailles.^[9][10][11]

The variety of the professional tasks that landscape architects collaborate on is very broad, but some examples of project types include:^[12]

• Parks of general design and public infrastructure
• Sustainable development
• Stormwater management including rain gardens, green roofs, groundwater recharge, green infrastructure, and constructed wetlands.
• Landscape design for educational function and site design for public institutions and government facilities
• Parks, botanical gardens, arboretums, greenways, and nature preserves
• Recreation facilities, such as playgrounds, golf courses, theme parks and sports facilities
• Housing areas, industrial parks and commercial developments
• Estate and residence landscape planning and design
• Landscaping and accents on highways, transportation structures, bridges, and transit corridors
• Contributions to urban design, town and city squares, waterfronts, pedestrian schemes
• Natural park, tourist destination, and recreating historical landscapes, and historic garden appraisal and conservation studies
• Reservoirs, dams, power stations, reclamation of extractive industry applications or major industrial projects and mitigation
• Environmental assessment and landscape assessment, planning advice and land management proposals.
• Coastal and offshore developments and mitigation
• Ecological design (any aspect of design that minimizes environmentally destructive impacts by integrating itself with natural processes and sustainability)

Landscape managers use their knowledge of landscape processes to advise on the long-term care and development of the landscape. They often work in forestry, nature conservation and agriculture.^{[citation needed]}

Landscape scientists have specialist skills such as soil science, hydrology, geomorphology or botany that they relate to the practical problems of landscape work. Their projects can range from site surveys to the ecological assessment of broad areas for planning or management purposes. They may also report on the impact of development or the importance of particular species in a given area.^{[citation needed]}

Landscape planners are concerned with landscape planning for the location, scenic, ecological and recreational aspects of urban, rural, and coastal land use. Their work is embodied in written statements of policy and strategy, and their remit includes master planning for new developments, landscape evaluations and assessments, and preparing countryside management or policy plans. Some may also apply an additional specialism such as landscape archaeology or law to the process of landscape planning.^{[citation needed]}

Green roof (or more specifically, vegetative roof) designers design extensive and intensive roof gardens for stormwater management, evapo-transpirative cooling, sustainable architecture, aesthetics, and habitat creation.^[13]

Through the 19th century, urban planning became a focal point and central issue in cities. The combination of the tradition of landscape gardening and the emerging field of urban planning offered landscape architecture an opportunity to serve these needs.^[14] In the second half of the century, Frederick Law Olmsted completed a series of parks that continue to have a significant influence on the practices of landscape architecture today. Among these were Central Park in New York City, Prospect Park in Brooklyn, New York and Boston's Emerald Necklace park system. Jens Jensen designed sophisticated and naturalistic urban and regional parks for Chicago, Illinois, and private estates for the Ford family including Fair Lane and Gaukler Point. One of the original eleven founding members of the American Society of Landscape Architects (ASLA), and the only woman, was Beatrix Farrand. She was design consultant for over a dozen universities including: Princeton in Princeton, New Jersey; Yale in New Haven, Connecticut; and the Arnold Arboretum for Harvard in Boston, Massachusetts. Her numerous private estate projects include the landmark Dumbarton Oaks in the Georgetown neighborhood of Washington, D.C.^[15] Since that time, other architects – most notably Ruth Havey and Alden Hopkins – changed certain elements of the Farrand design.^{[citation needed]}

Since this period urban planning has developed into a separate independent profession that has incorporated important contributions from other fields such as civil engineering, architecture and public administration. Urban Planners are qualified to perform tasks independent of landscape architects, and in general, the curriculum of landscape architecture programs do not prepare students to become urban planners.^[16]

Landscape architecture continues to develop as a design discipline and to respond to the various movements in architecture and design throughout the 20th and 21st centuries. Thomas Church was a pioneering mid-century landscape architect known for shaping modern American garden design.^[17] Roberto Burle Marx in Brazil combined the International style and native Brazilian plants and culture for a new aesthetic. Innovation continues today solving challenging problems with contemporary design solutions for master planning, landscapes, and gardens.^{[citation needed]}

Ian McHarg was known for introducing environmental concerns in landscape architecture.^[18][19] He popularized a system of analyzing the layers of a site in order to compile a complete understanding of the qualitative attributes of a place. This system became the foundation of today's Geographic Information Systems (GIS). McHarg would give every qualitative aspect of the site a layer, such as the history, hydrology, topography, vegetation, etc. GIS software is ubiquitously used in the landscape architecture profession today to analyze materials in and on the Earth's surface and is similarly used by urban planners, geographers, forestry and natural resources professionals, etc.^{[citation needed]}

European nations enabled the widespread circulation of urban planning strategies by transferring landscaping ideas and practices to overseas colonies. The green belt was a popular landscape practice exported by Britain onto colonial territories such as Haifa (1918-1948).^[20] Spatial mechanisms like the green belt, implemented through the Haifa Bay Plan and the British "Grand Model," were used to enforce political control and civic order and extend western ideas of progress and development.^[20] The Greater London Regional Planning Committee accepted the green belt concept which formed the basis of the 1938 Green Belt Act. The planning prototype demarcated open spaces, distinguished between city and countryside, limited urban growth, and created zoning divisions.^[20] It was used extensively in the British colonies to facilitate British rule through the organized division of landscape and populations. ^[20]

Indigenous land management practices create constantly changing landscapes through the use of vegetation and natural systems, contrasting with western epistemologies of the discipline that separate ornament from function.^[21] The discipline of landscape architecture favors western designs made from structured materials and geometric forms.^[21] Landscape architecture history books tend to include projects that contain constructed architectural elements that persist over time, excluding many Indigenous landscape-based designs.^[21]

Landscape architecture textbooks often place Indigenous peoples as a prefix to the official start of the discipline. The widely read landscape history text The Landscape of Man (1964) offers a global history of the designed landscape from past to present, featuring African and other Indigenous peoples in its discussions of Paleolithic man between 500,000 and 8,000 BCE in relation to human migration.^[21] Indigenous land-management practices are described as archaeological rather than a part of contemporary practice. Gardens in Time (1980) also places Indigenous practice as prehistory at the beginning of the landscape architecture timeline. Authors John and Ray Oldham describe Aborigines of Australia as "survivors of an ancient way of life" who provide an opportunity to examine western Australia as a "meeting place of a prehistoric man".^[21]

In the late 18th century, the landscapes created by aboriginal land and fire management practices appealed to English settlers in Australia.^[21] Journals from the period of early white settlement note the landscape resembling parks and popular designs in English landscape gardens of the same period.^[21] In England, these designs were considered sophisticated and celebrated for the intentional sacrifice of usable land. In Australia, the park-like condition was used to justify British control, citing its emptiness and lack of productive use as a basis for the dispossession of Aboriginal people.^[21]

Landscape architects are generally required to have university or graduate education from an accredited landscape architecture degree program, which can vary in length and degree title. They learn how to create projects from scratch, such as residential or commercial planting and designing outdoor living spaces.^[22] They are willing to work with others to get a better outcome for the customers when doing a project, and learn the basics of how to create a project on a manner of time, how to interact with clients and how to explain a design from scratch when presenting a final project.^[23]

Sustainable landscaping is a modern type of gardening or landscaping that takes the environmental issue of sustainability into account. According to Loehrlein in 2009 this includes design, construction and management of residential and commercial gardens and incorporates organic lawn management and organic gardening techniques.^[1]

A sustainable garden is designed to be both attractive and in balance with the local climate and environment and it should require minimal resource inputs. Thus, the design must be “functional, cost-efficient, visually pleasing, environmentally friendly and maintainable".^[2] As part of sustainable development, it pays close attention to preserving limited resources, reducing waste, and preventing air, water and soil pollution. Compost, fertilization, integrated pest management, using the right plant in the right place, appropriate use of turf and xeriscaping (water-wise gardening) are all components of sustainable landscaping.

Sustainability can help urban commercial landscaping companies save money.^[3] In California, gardens often do not outweigh the cost of inputs like water and labor. However, using appropriately selected and properly sited plants may help to ensure that maintenance costs are lower because of reduced inputs.

• Long-lasting
• Reduced water usage and no surface runoff or puddles
• Minimal use of fertilizers and pesticides
• Use of green waste
• Conservation of energy and resources^[4]

Sustainability issues for landscaping include:

• Carbon sequestration
• Climate change
• Water conservation
• Energy usage

Non-sustainable practices include:

• Consumption of non-renewable resources
• Greenhouse gas emissions

Some of the solutions are:

• Reduction of stormwater run-off through the use of bio-swales, rain gardens and green roofs and walls.^[5][6][7]
• Reduction of water use in landscapes through design of water-wise garden techniques (sometimes known as xeriscaping)^{[8][9][10][11]}
• Bio-filtering of wastes through constructed wetlands^[12]
• Irrigation using water from showers and sinks, known as gray water^[13]
• Integrated Pest Management techniques for pest control
• Creating and enhancing wildlife habitat in urban environments^[14]
• Energy-efficient garden design in the form of proper placement and selection of shade trees and creation of wind breaks ^[15][16]
• Permeable paving materials to reduce stormwater run-off and allow rain water to infiltrate into the ground and replenish groundwater rather than run into surface water^[17][18]
• Use of sustainably harvested wood, composite wood products for decking and other garden uses, as well as use of plastic lumber^[19]
• Recycling of products, such as glass, rubber from tires and other materials to create landscape products such as paving stones, mulch and other materials^[20]
• Soil management techniques, including composting kitchen and yard wastes, to maintain and enhance healthy soil that supports a diversity of soil life
• Integration and adoption of renewable energy, including solar-powered lighting^[21]
• Development of lawn alternatives^[22] such as xeriscaping,^[23] floral lawns,^[24] and meadows.^[25]

One step to garden design is to do a "sustainability audit". This is similar to a landscape site analysis that is typically performed by landscape designers at the beginning of the design process. Factors such as lot size, house size, local covenants and budgets should be considered. The steps to design include a base plan, site inventory and analysis, construction documents, implementation and maintenance.^[2] Of great importance is considerations related to the growing conditions of the site. These include orientation to the sun, soil type, wind flow, slopes, shade and climate, the goal of reducing irrigation and use of toxic substances, and requires proper plant selection for the specific site.

Sustainable landscaping is not only important because it saves money, it also limits the human impact on the surrounding ecosystem. However, planting species not native to the landscape may introduce invasive plant species as well as new wildlife that was not in the ecosystem before. Altering the ecosystem is a major problem and meeting with an expert with experience with the wildlife and agriculture in the area will help avoid this.^[26]

Mulch may be used to reduce water loss due to evaporation, reduce weeds, minimize erosion, dust and mud problems. Mulch can also add nutrients to the soil when it decomposes. However, mulch is most often used for weed suppression. Overuse of mulch can result in harm to the selected plantings. Care must be taken in the source of the mulch, for instance, black walnut trees result in a toxic mulch product. Grasscycling turf areas (using mulching mowers that leave grass clippings on the lawn) will also decrease the amount of fertilizer needed, reduce landfill waste and reduce costs of disposal.^[27]

A common recommendation is to add 2-4 inches of mulch in flower beds and under trees away from the trunk. Mulch should be applied under trees to the dripline (extension of the branches) in lieu of flowers, hostas, turf or other plants that are often planted there. This practice of planting under trees is detrimental to tree roots, especially when such plants are irrigated to an excessive level that harms the tree. One must be careful not to apply mulch to the bark of the tree. It can result in smothering, mould and insect depredation.

The practice of xeriscaping or water-wise gardening suggests that placing plants with similar water demands together will save time and low-water or drought-tolerant plants would be a smart initial consideration.

A homeowner may consider consulting an accredited irrigation technician/auditor and obtain a water audit of current systems. Drip or sub-surface irrigation may be useful. Using evapotranspiration controllers, soil sensors and refined control panels will reduce water loss. Irrigation heads may need readjustment to avoid sprinkling on sidewalks or streets. Business owners may consider developing watering schedules based on historical or actual weather data and soil probes to monitor soil moisture prior to watering.^[2]

When deciding what kind of building materials to put on a site it is important to recycle as often as possible, such as for example by reusing old bricks.

It is also important to be careful about what materials you use, especially if you plan to grow food crops. Old telephone poles and railroad ties have usually been treated with a toxic substance called creosote that can leach into the soils.

Sustainably harvested lumber is available, in which ecological, economic and social factors are integrated into the management of trees used for lumber.^[28]