Xeriscaping: A Guide to Water Conservation in Landscapes

Xeriscaping

A Guide to Water Conservation in Landscapes

What is Xeriscaping?

Xeriscaping is defined as a style of landscaping or gardening that promotes the ecological conservation of natural resources through water-smart design principles.

Xeriscaping Benefits

Xeriscaping serves a significant role in determining the environmental sustainability of a landscape and demonstrates synergetic advantages to both human and wildlife communities:

• Increases water conservation (50–75%).
•  Decreases maintenance, labour and cost.
• Decreases soil erosivity and erodibility.
• Increases soil infiltration, percolation and aeration.
• Minimizes or eliminates fertilizers and pesticides.
• Reduces carbon emissions, chemical pollution and contaminants.
• Provides wildlife resources for beneficial organisms.
• Increases property value (10–25%).

Xeriscape Design

Figure 1. The Xeriscape Demonstration Garden at Denver Water Headquarters in Denver, Colorado. © Jeffery Beall. 2015.

Xeriscape design is established on the basis of seven ecological principles: i) water conservation; ii) restricted turf areas; iii) efficient irrigation systems; iv) soil improvement; v) mulching; vi) drought-tolerant species; and vii) low maintenance. The following section contains ideas and concepts for implementing these xeriscaping principles into an urban garden or landscape.

Water Conservation	Group vegetation with similar watering requirements into specific hydrozones to increase watering efficiency. Apply water in the morning when evaporation rates are lowest. Study natural contours and drainage patterns to prevent precipitation runoff and erosion.
Restricted Turf Areas	Eliminate or reduce turf by only installing drought-tolerant mixes in areas with practical functionality to increase water efficiency and reduce evapotranspiration (30 – 60%). Groundcovers, rockeries and tiered gardens can be implemented to minimize turfgrass.
Efficient Irrigation Systems	Drip (syn. tube) irrigation is considered to be the most efficient irrigation system in xeriscaping. Drip irrigation prevents moisture stress by supplying a slow, steady supply of water on the soil surface or directly into the root zone (2.0-8.0 L/hr) and provides uniform moisture distribution in less surface area compared to other irrigation systems (10–20%). Stormwater management can supplement irrigation via rain barrels, cisterns or green roof systems.
Soil Improvement	Add soil amendments to improve soil structure, infiltration, percolation and aeration. Soil amendments include sphagnum peat moss¹, compost, green manure, casts, coir, rice hulls, biochar, calcined clay, perlite, vermiculite and sand. Analyze soil texture, nutrient composition and pH with testing kits. Aerate soil sparingly to facilitate gas exchange. Do not cultivate soil during wet conditions. Do not overcultivate.
Mulching	Lay mulches around herbs, forbs, shrubs and trees. Mulches include wood, bark², needles, leaves, straw, stone and gravel. Organic and inorganic mulches should be incorporated at the appropriate depth (5.08–12.7 cm) as deep mulches can procure poor soil drainage. Organic mulches should be replenished every year to offset decomposition. Choose coarse-textured mulches over fine-textured mulches. Avoid mulches that have been painted or chemically treated. Do not use non-permeable landscape fabric or plastic as these materials prevent groundwater charge.
Drought-Tolerant Species	Incorporate drought-tolerant species with defining characteristics (e.g. small, thick, glossy, succulent, glaucous or pubescent leaves) or native species with climate, insect and disease resistance. Small shrubs and herbs can reduce pruning maintenance. Avoid monocultures to create biodiversity and decrease pest virulence.
Low Maintenance	Proactive maintenance includes judicious watering and fertilizing, replenishing mulches, weeding, prohibiting shearing, fixing broken irrigation and mowing at the appropriate height (5.08–6.57 cm).

For more information on how to start your own xeriscaping project, check out Creating the Prairie Xeriscape (2013) by Sara Williams.

¹ – Sphagnum peat moss is considered an unsustainable soil amendment. Consider sustainable alternatives such as compost, green manure, casts, biochar, coir or rice hulls.

² – Check out The Myth of Pretty Mulch (2015) by Dr. Linda Chalker-Scott to read about the negative apsects of using bark mulches in landscaping applications.

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When in doubt, contact a professional to ensure your garden is ready for any climate. Contact us for a horticulture consultation today!

Prairie West Landscapes

3541A 78 Ave SE

Calgary, AB T2C 1J7

(403) 252-6330

info@pwlscapes.com