PLANTING SEEDS

How to keep climate change in mind for landscaping projects

IN RESPONSE TO growing public awareness about climate change and extended periods of drought, some builders are examining a process of gardening and landscaping traditionally reserved for arid regions. It’s called xeriscaping, and its aim is to reduce or eliminate the need for irrigation.

A properly designed outdoor xeriscape not only reduces water usage by 20-50% but also cuts chemical usage, requires little maintenance and creates a unique aesthetic. It further allows for a wide range of trees, shrubs and flowering perennials, while removing the need for the constant mowing of a traditional lawn.

The organization of a xeriscape takes into consideration the creation of water-use zones, or hydrozoning, to add efficiency to watering and reduce waste. Plants should be clustered together into zones that require frequent watering, occasional watering, or no watering at all to avoid over- or under-watering certain species. These zones should then be correlated with the sun. Zones that require lots of watering should be kept out of high sun exposure to reduce evaporation from the soil.

Conversely, plants with lower water requirements should be placed in areas with more sunlight.

High-water-use zones should be limited in size and, if possible, be placed in highly visible areas such as entranceways due to the fact that these plants tend to be more aesthetically pleasing and lush.

The other consideration for a garden is the topography and subsequent drainage patterns. Slopes that cause excessive runoff should be terraced to allow rainfall to seep into the ground for plant use, while low spots that drain poorly should either be avoided or designed to aid in their drainage. High-water-use plants can be planted in low spots, provided it is not too wet for the vegetation. By regarding the water drainage patterns within the yard, it’s possible to customize the area with backfill and redirect the water to locations where it’s most needed.

The low-water-demand garden is a highlight of Ross Street House in Madison, Wisconsin, the state’s first home to with a LEED Platinum rating. In collaboration with her mechanical engineer husband, architect Carol Richard of Richard Wittschiebe Hand provided detailed specifications for the planting of xeriscape gardens in both the front and rear yards of her three-storey, 2,700 sq. ft. home. The landscape was transformed into an edible yet extremely water-efficient garden. Plants such as wild strawberries, western sunflowers and herbs are just a few examples. Native perennials requiring little maintenance were included.

To complement the exterior of neighbouring houses and their proportions, the exterior walls are clad with 6” tongue-and-groove cedar siding.

The three storeys are connected by a central staircase that lets natural light flow through. The private living room and bedrooms sit on the third floor, while the below-grade basement accommodates guests, mechanical hardware, storage and even a Belgian-style beer brewing room! The living, kitchen and dining spaces are on the main level, with plenty of windows looking out over the outdoor vegetation.

Could this mark the beginning of our parting ways with sod?

Avi Friedman IS AN ARCHITECT, PROFESSOR, AUTHOR AND SOCIAL OBSERVER. AVI.FRIEDMAN@MCGILL.CA