Green Landscaping

Green landscaping is an emerging landscape design approach that, in contrast with conventional landscaping, focuses on environmentally-friendly principles. Conventional landscaping represents any alteration of visible features of land, in various scales, and with different management concerns; for example, daily gardening work for a homeowners’ backyard, a poolside garden in a holiday resort, or an urban park in a downtown area with ornamental and recreational facilities. Landscaping has traditionally been designed to enhance the visual beauty of the surroundings from a human's point of view. However, some conventional landscaping, gardening routines, or practices posing heavy resource demand impair ecosystems or have other negative effects.

Principles of green landscaping can be concluded from perspectives of design and maintenance. They include the following:

• Mimicking the natural processes in gardens and urban green spaces for both maximum environmental (promoting ecological diversity and the habitat's connectivity in urban areas) and economic efficiencies (saving time, resources, and money) in a sustainable manner
• Selecting appropriate plants (preferably native plants), and using water efficiency (e.g., xeriscaping) and conservation measures to consciously reduce maintenance and water requirements, as most native plants can thrive with minimal care
• Avoiding massive clear-cutting of indigenous plants when planning a landscaping project, and incorporating and preserving original landscape characters and their seasonal interest and “sense of places” as much as possible (e.g., preserving mature trees, terrains, bodies of water, etc.)
• Using recycled materials thoroughly, such as mulch, other soil amendments, and landscape construction materials (e.g., using recycled plastic bender board, pieces of used concrete, paving stones from abandoned or old gardens, or recycled brick)

Traditional landscaping is conducive to environmental degradation, including greenhouse gas and volatile organic compound emissions by lawn and garden equipment, water pollution by fertilizers and pesticides, increased chance for flooding because of erosion, habitat loss originated from invasion of exotic plants, and consumption of natural resources. The traditional approach emphasizes a greening effect by adopting short-lived flowering plants, transplantation of mature trees, and massive turf—this kind of design often creates a monotonous landscape that requires intensive maintenance and thus depletes resources.

Green landscaping has several synonyms, including sustainable landscaping, ecofriendly landscaping, and natural landscaping. As a rule of thumb, green landscaping encourages careful sustainable design with natural landscaping. It can bring the feel of wilderness to [Page 235]urban environments and attract birds, butterflies, and other animals. Such landscapes can sustain their own microecosystems once established. Native plants do not need extensive fertilizers, herbicides, pesticides, or watering.

William Thompson and his colleagues wrote a comprehensive guidebook on how to construct outdoor, built environments based on principles of sustainability, and they put forward 10 principles for practitioners to follow and shed insights to landscape architectural practices:

• Keep healthy sites healthy: Incorporate a baseline survey as an essential and integral part of planning, avoid utility damage by easement and trenches, minimize the adverse degradation of the site during constr]uction and preserve healthy topsoil, save existing trees, and use appropriate construction machinery
• Heal injured sites: Restore landscapes structurally, restore damaged soils on-site, and restore regionally appropriate vegetation
• Favor live and flexible material: Hold sloped land in place with biotechnical erosion control, make vertical structures habitable with green walls, turn barren roof spaces into green roofs, and construct for and with plants
• Respect natural water sources: Restore natural wetlands, rivers, and streams; collect and conserve water; irrigate intelligently and sparingly; reuse greywater; purify water at every opportunity; and let constructed wetlands treat water
• Pave less: Plan and design to reduce paving by taking advantage of context-sensitive road design, use techniques that reduce runoff from paving, use porous paving materials, and cool asphalt with planting and albedo
• Consider the origin and fate of materials: Reuse and use local salvaged or recycled materials, evaluate environmental costs when choosing suppliers, avoid toxic and nonrenewable materials, become familiar with toxicity issues by material type, and avoid polyvinyl chloride, preserved wood (wood preservatives), and fertilizers (heavy metals, toxic chemicals, and radioactive waste)
• Know the costs of energy over time: Understand how landscape energy use is different with the use of different machines, tools, and labor; use life-cycle costing to justify sustainable design; and apply guidelines for landscape energy conservation
• Respect the need for darkness and use lighting efficiently: Use lighting only if necessary, try low-voltage lighting for flexibility, and evaluate lamp performance and adopt light-emitting diode lighting
• Quietly defend silence: Push for quieter landscape tools and modify pavement to reduce road noise
• Maintain to sustain: Know the resource costs of traditional landscape maintenance, switch to bio-based maintenance products, apply integrated pest management, use fertilizer sustainably, use on-site resources, consider alternatives to mowing, evaluate life-cycle costs of maintenance options, and coordinate design, construction, and maintenance

Green landscaping is not only applicable to backyards, public parks, or commercial resorts; it also provides substantial improvement to environmental quality along roads and highways, golf courses, and bridges. Golf courses and roadside environments are conditioned with composts to control erosion and facilitate revegetation. Some parks use recycled tires and plastic lumber in pathways, playground surfaces, and flooring tile.

...