Why Xeriscape, the Okanagan environment, and growing conditions of the Okanagan

Why Xeriscape?

If you want your garden to give you the maximum enjoyment and value for your expenditure of time and money, xeriscaping is the answer! Xeri (rhymes with terra) is the Greek word for dry. Xeriscaping is gardening with your natural environmental conditions rather than fighting against them.


  • Enhances the value of your home with an attractive and water conserving landscape.
  • Reduces water use- depending on the design and the plants used, water use can be reduced by over 50%.
  • Saves time– less watering, trimming, weeding and mowing.
  • Saves money– less water, chemicals, fertilizer, and replacement of dead plants.
  • Eliminates pesticide/herbicide use– plants growing in their ideal conditions thrive.
  • Protects your family’s health and that of the environment – including keeping poisonous chemicals out of our water.
Growing Conditions
The mean daily temperature in January is between 0 and -5C (32 and 23F), while in July, it’s 20 to 22C (68 to 72F). However, in winter it is not uncommon for temperatures to plunge to -32C (-26 F), while in summer, they can soar to 40C (104 F). Hot, sunny summers and fairly mild, overcast winters put the Okanagan in plant hardiness zones four to six.
*USDA plant hardiness zones are calculated by the average lowest winter temperature- the Okanagan is zone 1 to 5.
The average annual precipitation is about 280 millimetres (11 inches), approximately half of this falling as snow in winter. Summers are getting drier and two to eight weeks without any rainfall is becoming common. When it does rain, it often comes as a very short, heavy downpour in a thunderstorm. Frequently this welcome rain falls too fast for the parched soil to absorb the water and so it runs off into streams and storm drains.
The soils have a tendency to be alkaline rather than acidic, with an average pH of 7.6. Due to low precipitation, growth of natural vegetation is slow and there is very little organic matter in the soils.
The Okanagan Environment
The Okanagan Valley features a string of seven lakes along its length of approximately 160 kilometres (100 miles). The valley was carved out by glaciers during the last ice age occurring in about 16,000 B.C. Today, the Okanagan Valley is a semi-arid climate, and includes the only desert in Canada at its southern end. The average annual precipitation is about 280 millimetres (11 inches).
Natural vegetation along the valley bottom, which is at about 300 metres in altitude (1,000 feet), is predominantly Ponderosa Pine and Bluebunch Wheatgrass habitat, along with cactus, Rabbitbrush and sagebrushes in the south.
The land slopes up on either side of the main stem lakes to 500 metres (1,700 feet) on the bench lands. Here in spring, the showy Arrow-leaved Balsamroot turn the hillsides yellow with their blooms against a backdrop of abundant white-flowered Saskatoon bushes. In summer the hills turn brown as the grasses die back for lack of rain. A fall feature is the red berries of the sumac, paired with the grey foliage of the sagebrushes and vivid yellow bloom of Rabbitbrush.
Wildlife include white-tailed and mule deer, yellow-bellied marmot, coyotes, cougars, lynx, black bears and the occasional grizzly bear, as well as moose and elk at higher elevations, and small populations of California bighorn sheep and mountain goats.
The valley has the greatest diversity and population density of bats of any region in Canada and it is host to more than 330 species of birds, more than 200 of which breed locally. Many plant and animal species are found nowhere else in Canada and due to development and human activity many are threatened with extinction.
Favourite plant today: Daylily
Common name Daylily Latin name Hemerocallis varieties Type Perennial Height 12-48″ Spread 12-30″ Light & Water Full sun: Part sun: Zone 2 Bloom months
  • May
  • June
  • July
  • August

Bloom colour White, pale yellow, bright yellow, gold, orange, pale pink, deep pink, red, violet, mixed colours Foliage colour Green, grass like Features

  • Attracts hummingbirds
  • Deer resistant
  • Edible
Notes Hundreds of varieties available, including bicolours and doubles. Bloom for 3-4 weeks but early mid and late season blooming varieties are available. Underplant with spring bulbs and add some grasses for easy care garden.
Health Tip:
The Canadian Cancer Society is very concerned about the use of cosmetic chemical pesticides, which can contain carcinogens, for the purposes of controlling unwanted weeds and plants on lawns and gardens (cosmetic use).
Cosmetic chemical pesticides have been linked to various cancers and children are at a greater risk. What’s more, these chemicals are unnecessary. Safe, effective, non-toxic alternatives exist and the use of these alternatives is good for business and can grow the green economy.  Integrated Pest Management (IPM), or the use of pesticides ‘as a last resort’ to deal with weeds and insects, should not be included in cosmetic pesticide legislation.When it comes to cosmetic chemical pesticides, the Canadian Cancer Society endorses the precautionary principle and is calling on the BC government to ban the sale and use of cosmetic pesticides.

Lush Mountain Landscaping “Improving the world we live in”