Xeriscaping for sustainability

Xeriscaping (pronounced “Zera-scaping”) is a more sustainable alternative to traditional landscape practices which use exotic plants and standard green lawns in arid areas and contribute to excessive water use, photochemical air pollution, and ecological damage. Xeriscaping involves lower conversion of local habitat, and benefits biodiversity, providing a cultural anchor, while also supporting recreation.



Keywords: xeriscaping, landscaping, native species, exotic species

The term “xeriscaping” defines the process of making landscapes more water-efficient. This is achieved in the design phase as well as through proper planting, and good water management practices. The concept, first coined in Colorado in 1981, has been developed into seven principles:

• Suitable planning and design
• Practical lawn areas (using turf only when it provides functional benefits)
• Efficient irrigation
• Soil protection and improvements
• Appropriate plant species selection
• Maintenance to reduce water requirements

Regulation and incentives
The first site to pass a xeriscape regulation was Florida in 1991. California, Arizona, Nevada, and Toronto have since followed with various legislation and incentives for property owners to incorporate weather efficiency into their landscaping.

Water savings translates to less pressure on aquifers, and reduced soil pollution from irrigation. A study comparing conventional and water-efficient landscapes in Northern California found savings of 54% for water, 25% for labour, 61% for fertilizer, 44% for fuel, and 22% for herbicides. Other studies in dry regions, such the Mojave Desert, have demonstrated that xeriscaping reduces water use by up to 80%, and results in a 30% decrease in maintenance costs and labour. On the basis of these savings, research on xeriscaping as an investment found a potential return of investment within 4 years.

Indigenous species
Apart from providing water and cost savings, xeriscaped environments also ensure that the greening of cities is ecologically sustainable, by promoting the planting of local species and thereby restoring indigenous environments (see also Adelaide, Auckland and Mata de Sesimbra). This is a vital part of the overall well-being of ecosystems and benefits citizens: not only promoting biodiversity but also forming a cultural anchor for urban biodiversity. Furthermore, a more sustainable urban greenspace thwarts the loss of native species through exotic species invasion, and provides better use of limited space.


References
N.E. Hostetler, M.E. McIntyre, 2001, ”Effects of urban land use on pollinator (Hymenoptera: Apoidea) communities in a desert metropolis”, Basic and Applied Ecology, Vol 2, Issue 3

M. Ignatieva, 2010, “Design and Future of Urban Biodiversity”, in N. Müller, P. Werner and J.G. Kelcey (eds.), Urban Biodiversity and Design, Oxford: Wiley-Blackwell

Maria Ignatieva, Colin D. Meurk, Marjorie van Roon, Robyn Simcock, Glenn Stewart, 2008, “How to put nature into our neighbourhoods: application of Low Impact Urban Design and Development (LIUDD) principles, with a biodiversity focus, for New Zealand developers and homeowners”, Urban greening manual, Landcare Research science series, no. 35, Manaaki Whenua Press, http://www.kapiticoast.govt.nz/Documents/Downloads/How-to-Put-Nature-Into-Our-Neighbourhoods.pdf

J.E. Ingels, 2009, Landscaping principles and practices, 7th ed., Delmar Cengage Learning, Clifton Park NY US

J.F. Karlik, A.M. Winer, 2001, ”Plant species composition, calculated leaf masses and estimated biogenic emissions of urban landscape types from a field survey in Phoenix, Arizona,” Landscape and Urban Planning, (53) 123-13

Text by: Aaron Thomas