1. G1405 (Revised March 2009) Landscape Sustainability Steven N. Rodie, Extension Landscape Horticulture Specialist Anne M. Streich, Horticulture Educator Functional principles dictate whether the design will This NebGuide describes how to use aesthetic, be usable and will meet certain health and safety criteria. functional and environmentally sound design principles For example­ drainage must be routed away from the foun­ , to create a sustainable landscape. dation of a home; sidewalks and outdoor spaces should be sized appropriately for homeowner and visitor use; and “Sustainable landscapes” commonly describes land­ landscapes should include areas dedicated to private, public,scapes that support environmental quality and conservation and utility needs.of natural resources. For many people, a sustainable land­scape is hard to understand or visualize. Other terms such Environmental Design Principlesas xeriscape, native landscape, and environmentally friendlylandscape have been used interchangeably to describe sus­ Environmental design is the third category of designtainable landscapes. principles. The focus of these principles is to: A well-designed sustainable landscape reflects a highlevel of self-sufficiency. Once established, it should grow 1) enhance landscape microclimate;and mature virtually on its own — as if nature had planted 2) increase biodiversity;it. This self-sufficiency can be difficult to attain, however, 3) reduce resource inputs and resource waste; anddue to the environmental stresses and artificial conditions 4) maximize reuse of resources.placed on plants in urban areas. In addition, many residentsmay not be comfortable with the informality (less plant The diagrams on pages 2 and 3 illustrate how these principlespruning, use of native plants which may lack the desirable can be implemented in a typical residential landscape.aesthetic features of typical landscape plants, etc.) normally Enhance landscape microclimates through:reflected in a sustainable landscape. Adjusting to an informal landscape may take time for • channeling or screening winds;many homeowners, but implementing just one or a few • shading structures and outdoor living areas from theprinciples of sustainable design can significantly benefit summer sun while providing for winter sun exposure;home landscapes. These benefits may include enhanced andlandscape beauty; less environmental decline; more effective • increasing or decreasing humidity (or the perceptionuse of water, pesticides and other chemical resources; more of humidity) through adjustments in air movement.valuable wildlife habitat; and cost savings from reducedmaintenance, labor and resource use. These enhancements can lead to lower energy and water use, healthier plants (which are capable of resisting diseases Aesthetic and Functional Design Principles and insects with less chemical assistance), and more usable outdoor living space. Many design principles typically are reflected in a well- Biodiversity refers to the natural variety of plants, ani­designed landscape. Although sustainable landscapes may mals, fungi, and microorganisms found in all ecosystems.appear more “natural” and less manicured, they still rely Increasing biodiversity, whether in a backyard, neigh­ orhood bon all of the standard design principles to create a visually park, or along regional creeks, brings many benefits toappealing­combination of plants and materials. landscapes. Aesthetic principles including accent, contrast, har­ Planting landscapes that more closely reflect nativemony, repetition and unity ensure the design is attractive, plant communities can enhance biodiversity. To achieve this,visually compatible and has a “sense of fit” with the sur­ develop­understory/overstory vegetation similar to the layer­rounding landscape. ing of plants in a natural forest. Biodiversity also assumes (Continued on page 4)
2. Illustrated Sustainable Design Principles in a Residential Landscape, Part A 1 3 7 5 8 2 6 41. Windbreaks and shelterbelts conserve energy, 5. Grouping similar plants into masses creates a control drifting snow, provide food and shelter for stronger­visual impact and interest in the landscape, wild­ ife, screen unwanted views, filter dust and l copies natural plant community structure, and noise, and create microclimates that benefit plant produces stronger edges in the landscape that are health. important for both aesthetics and habitat.2. Berms (gradually sloped mounds of soil) help 6. Selectively use higher maintenance turfgrasses in define­landscape spaces by creating sloping “walls” areas of high visibility, access, and use. along pathways or between different areas, elevating plants for better visibility, and improving drainage 7. Use lower maintenance turfgrasses and prairie or and growing conditions for plants in poor soil. adapted grasses in areas of low use and access (not necessarily low visibility).3. Ornamental grasses tolerate a wide variety of con­ ditions, provide food and cover for wildlife and 8. Use organic mulch in all planting beds to increase soil offer year-round visual interest. Many of these water retention, reduce weeds, visually strengthen ornamental grasses are native to the Great Plains. bed lines through the color and texture contrast between the mulch and turf, minimize short-term4. Groundcover plants used on steep slopes eliminate swings in soil temperatures, and enhance soil struc­ dangerous turf mowing conditions, lessen precipi­ ture and organic matter content. tation runoff and soil erosion, and provide additional visual interest and biodiversity.
3. Illustrated Sustainable Design Principles in a Residential Landscape, Part B 17 19 10 13 15 12 14 16 11 18 99. A properly designed, installed and calibrated irri­ 15. Composting garden waste and applying the resulting gation system minimizes uneven or wasteful water organic matter in the landscape improves growing application. conditions and recycles valuable resources.10. Group plants with similar water needs to avoid 16. Using recycled and/or local-source building over- or under-watering. materials­ (plastic lumber, prairie fieldstone, etc.) can help develop markets for recycled products,11. Use drip irrigation for shrub beds and other beds to lessen product and installation costs and visually minimize water waste. tie developed landscapes to the character of natural12. Properly select plants for the conditions in which they landscapes. are placed (example: sun and wind exposure, soil 17. Manipulating microclimates by using overhead type and soil moisture conditions). Properly selected vines, shade structures, and trees enhances the liv­ plants will ensure a healthy landscape with minimal ability of outdoor spaces. need for chemicals or additional management. 18. Raised beds improve access to plants, make it easier13. Landscape “vertically” as nature does. Placing small to manage the soil, and improve growing conditions plants and groundcovers under small trees under by increasing soil aeration and drainage. large trees enhances both visual and biological diversity. 19. Where feasible, use plantings to connect developed landscapes with natural landscape areas. These14. Creating wildlife habitat draws birds and other ani­ integrated landscapes are considered more envi­ mals, which add to the aesthetics of the landscape ronmentally valuable than small, scattered areas and offer biological control of unwanted insects. of vegetation.
4. plants are placed in conditions and environments where storage is increased, and the living organisms in the soil arethey would naturally grow. Additionally, biodiversity can healthier.be increased by: Whenever the topsoil is not available for reuse, due to removal or severe compaction, incorporate organic amend­ • using plants that provide habitat for wildlife and year- ments such as compost into the remaining soil to enhance round aesthetic interest; its ability to support newly established plants. • considering alternative methods of storm drainage Maximizing and reusing resources has recently management such as rain gardens and allowing run-off received­notable attention in the form of recycling campaigns to percolate through porous surfaces, or implementing for everything from newspapers to used tires. Effective flood control measures along creeks that are sensitive sustainable design not only incorporates recycled materials to existing vegetation and habitat; and (paving­­­ materials, mulches, building materials, etc.), but • preserving existing natural areas in urban settings that also addresses how communities can recycle for the good provide habitat as well as aesthetic or recreational of their landscapes. value. Composting can be integrated into a residential back­ yard garden for kitchen and yard waste or a regional solid Reducing resources and minimizing waste in waste program aimed at reducing landfill while providinga landscape can be accomplished in many ways. For a source of organic matter for city/county park sites.example, by choosing the correct plants and their loca­tions, watering, pruning, and chemical applications will Getting Startedbe reduced. Accepting­ insects and diseases that are notlife-threatening to landscape plants (for example, some By implementing the principles outlined in this Neb­leaf feeding or leafspot is okay) is another way to reduce Guide, Nebraska’s residential landscapes can be made morechemical use and other resources. Applying­mulch to the sustainable. Applying even the most basic principles —soil under plants reduces weed growth that in turn reduces proper plant selection and placement for example — canchemical treatments and use of gas-powered trimming benefit the aesthetics­ environment and budget of the typical ,equipment. In addition, the mulch improves soil quality home landscape. Properly selected plants are healthy plantsover time, minimizing water waste caused by run-off and that have fewer insect and disease problems and, therefore,evaporation. require­ less maintenance. Properly sized trees and shrubs Soils are typically the most misunderstood and need little pruning, and drought-tolerant perennials needundervalued­ resource in urban landscapes. Soil quality minimal irrigation­ .and character significantly affect the growth and health ofplants, and should be major considerations in landscapeinstallation. This publication has been peer reviewed. Whenever previously undisturbed landscape areas areslated for construction, the top 6 inches of soil should bescraped off and stockpiled. Save the soil and reincorporateit as the final layer of soil once construction is completed. UNL Extension publications are available onlineSince a substantial amount of root growth occurs in the at http://extension.unl.edu/publications.top 6-12 inches of soil, this reused soil can significantlyenhance the establishment and growing conditions for newplants. Drainage and water retention are improved, oxygen Index: Horticulture Miscellaneous 2000, Revised March 2009 Extension is a Division of the Institute of Agriculture and Natural Resources at the University of Nebraska–Lincoln cooperating with the Counties and the United States Department of Agriculture. University of Nebraska–Lincoln Extension educational programs abide with the nondiscrimination policies of the University of Nebraska–Lincoln and the United States Department of Agriculture. © 2000-2009, The Board of Regents of the University of Nebraska on behalf of the University of Nebraska–Lincoln Extension. All rights reserved.