How to Save Water in Your Garden
Lawns and rose gardens can become sustainable — financially, environmentally, and ecologically.
Dear Avant Gardener, California is going after water for lawns, and our village has from time to time banned watering grass altogether. So we’re about to rip out a rose garden for something less thirsty. Roses are a big deal here, celebrated by the Rose Parade on New Year’s Day. And I clip the roses for little vases in the house. But we like lawn games as a family activity, so we’ll give up the roses in favor of ring toss. Our lavender does well and I’m wondering if more lavender is in our future. — Kathleen, La Canada (near Pasadena), CA
Ouch, painful choices! Lack of water in much of the country, especially California, is forcing changes in American yards. Fortunately, you can maintain what you love about your yard while making it more sustainable. In fact, it’s feasible to eliminate using household water to irrigate without changing how you use your yard.
Traditional turf hogs water, so replacing it will have a bigger impact on your water usage than replacing roses. Have you turned your carpet of grass into an area rug and planted native trees, shrubs and perennials in the unused sections? A 30 by 50 foot area (1,500 square feet) is sufficient for badminton or home croquet, as well as ring toss. California native plants use 90 percent less water than traditional turf, so replacing just 100 square feet of lawn with natives will eliminate the need to irrigate there, saving a couple of thousand gallons of water per year.
Once you’ve defined your lawn areas, installing low-water alternative turf can dramatically reduce water use without affecting your enjoyment of the lawn. California native grass sod from Camarillo-based Soil Solutions, for example, requires half as much water as traditional turf. That translates to roughly 14,000 gallons less household water to irrigate 1,500 square feet of lawn during the 30 weeks when La Canada and Pasadena do not get an inch of rain. Alternatively,
Alternative water sources
For the 14,000 or so gallons you’ll need to irrigate a 1,500 native grass lawn during the dry season, you might consider installing a 10,000 gallon cistern. La Canada’s 22 annual inches of rain on a thousand square foot roof will more than fill it. Rainwater is actually better for plants, because it is free of chlorine, fluoride and other chemicals. The cost of the cistern, as well as replacing turf, may be offset by grants through SoCal Watersmart.
As for the rose garden, I’m all for replacing traditional roses with native plants to support native insects. However, before you rip out the rose garden — the way you phrased that sounds painful — you might consider installing a greywater irrigation system instead. These systems route wastewater from your washing machine, showers, baths, and bathroom sinks to your garden. A two-person household generates about 70 gallons of greywater per day — or roughly 500 per week. That’s sufficient to water 1,000 square feet of ornamental gardens, which consume 20 percent less water than lawns.
Please, not more lavender!
Lavenders are exotic (i.e., non-native), with the most common one (Lavandula angustifolia) hailing from the Mediterranean. Although lavender evolved in a similarly low-water climate, California’s native insects did not evolve with it. As you’ve heard me say before, insects are the foundation of our terrestrial ecosystem and most insects depend for survival on the specific plants they evolved with. So plant native sages instead to help avert mass extinction.
Your rose garden honors the local rose tradition and provides cut flowers for your home. You can do both these things while reducing water use if you replace some or all of it with native roses and native cutting flowers.
What's more, exotic varieties of roses are often short of pollen and nectar, which are crucial food sources for a variety of insects and other creatures. “They're all show and no go,” says entomologist Stephen Buchmann of the U.S. Department of Agriculture. “Native roses are better because they contain a full complement of pollen and nectar,” attracting bumblebees, birds and other important pollinators. —National Wildlife Federation
California wildrose (Rosa californica), native to La Canada, works best as a hedge in the background where there’s plenty of room. In front of the roses, you can plant a cutting garden starting with the six below in cream, pink, and purple hues that will harmonize with California wildrose and lavender. Most are available near you at Pasadena’s Hahamonga Native Plant Nursery.
— The Avant Gardener
Why, How, Wow!
Two thirds of the country receives less rain than a traditional lawn requires — 55 inches per year. Installing alternatives appropriate to each region can reduce or eliminate the need for irrigation (supplementing rainwater), especially when combined with rainwater or greywater capture systems.
Using water-saving techniques can save you money and diverts less water from our rivers, bays, and estuaries, which helps keep the environment healthy. It can also reduce water and wastewater treatment costs and the amount of energy used to treat, pump, and heat water. This lowers energy demand, which helps prevent air pollution. — energystar.gov
The situation is especially acute in California, where one in 10 California households is falling into arrears on water payments, which can run $200 per month.
Native plants typically have deeper roots than exotic (non-native) garden plants. This helps them tolerate drought conditions. They don’t need supplemental water except for an establishment period of about six months. (In fact, watering in summer can kill California asters and other natives.) To maximize the amount rainwater available during establishment, plant in fall in many areas of the country.
Low-water southwestern plants aren’t all cacti and yucca. The California “Mediterranean” ecoregion — most of the coast from San Francisco south — supports lush flowering perennials and shrubs.
This region has a Mediterranean climate with mild, wet winters and dry summers. . . . Along the coast, fog provides some moisture, and high relative humidity and extensive cloud cover reduces evapotranspiration, allowing for lusher plant growth than would normally occur in a region with as little rainfall as this one. — bplant.org
Creating a California native garden? Search for “right plant, right place” by specifying your conditions and preferences in the advanced search function at Calscape.
Want to know more about turning your carpet of grass into an area rug? See “Love, Hate & 9 Lawn Questions.”
Interested in greywater and rainwater capture systems? You’ll find DIY info at Greywater Action.