Innovative horticulture emphasizes water conservation and native plants
LANDSCAPE architect Terry Lewis often spends his spare time wandering through abandoned, overgrown lots in poor sections of San Antonio.
It's an ideal laboratory for discovering what kind of local plants and vegetation thrive naturally - without frequent watering and careful tending.
Mr. Lewis then takes this field research across town and designs xeriscape landscapes for the expansive yards of wealthy San Antonio residents.
Xeriscape (pronounced zeer'-i-skape) is officially defined as "water conservation through creative landscaping." The term was coined in 1981 by the Denver Water Department in response to an ongoing drought.
On a tour through the wide residential streets of San Antonio, Lewis points out xeriscape landscapes scattered among the traditional sprawling lawns. The conventional approach to landscaping is to plant grass everywhere and follow up with a few beds next to the house.
Xeriscape landscapes involve a more limited lawn and heavily mulched, meandering beds with a wide variety of drought-resistant plants. Plants with similar water needs are usually grouped together for more efficient watering.
One San Antonio xeriscape yard has no front lawn, and the beds host an eclectic group of sages, ornamental grasses, and perennials.
In another neighborhood nearby, a more organized, formal xeriscape landscape includes a small front lawn bordered by wide stretches of beds on all sides. Spider lilies flourish and mountain laurel shade colorful begonias.
Xeriscape is a derivative of the Greek word xeros, which means dry. This has caused widespread confusion about xeriscape landscapes, says Doug Welsh, past-president of the National Xeriscape Council and a horticulturist at the Texas Agricultural Extension Service at Texas A&M University.
For example, some people think that these landscapes require no supplemental water. "We're not talking cactus and rocks," Dr. Welsh says.
"There's a big difference between xeriscape and zero-scape," Lewis says. "When it first came out, it was a brand new word, and I think that hurt the industry."
Others argue that the mysterious term is helpful. "It's a million-dollar word," says Fox McCarthy of the Cobb County-Marietta Water Authority in Marietta, Ga. "People hear the word and ask, `What's that?' If I were to tell you about water-efficient landscape, you'd say, `Oh, OK, that's nice.' But when you say xeriscape, it hits a chord and makes people listen."
The National Xeriscape Council and local utilities nationwide are doing whatever they can to promote understanding of xeriscape principles. "If the general public perceives xeriscape as weedy, and wild, and not blooming for more than half the year, they're not going to like it," Lewis says.
In fact, many gardeners complain that xeriscape landscapes aren't lush enough, or tidy enough to fit their tastes.
"At first, people associated xeriscape with a style - a native woody landscape. And maybe that's not what fits in with the neighborhood," Lewis says. The key is understanding that "xeriscape has nothing to do with style," he says.
According to Lewis, "a xeriscape can be a very formal garden or a very informal space.... It's really just good, sound horticultural techniques."
Xeriscape concepts were developed in response to nationwide concerns about limited water resources. Forty to 60 percent of all summer water use is for landscape maintenance, the National Xeriscape Council estimates.
Xeriscape techniques can decrease water use by half, Lewis says. "It's like plugging in an efficient light bulb."
The National Xeriscape Council outlines seven principles of xeriscape landscaping:
* Start with a good design.
* Improve the soil.
* Choose low-water-use plants.
* Limit lawn areas.
* Water efficiently.
* Use mulch.
* Practice good maintenance.
"The best kind of xeriscape is the kind that incorporates all of these principles," Lewis says. And he'd like to add one more to the list: creating shade through the use of trees. "That would do a whole lot to reduce water use," Lewis says.
Little things can make a big difference in conserving water through landscaping. "The amount of water that you can conserve by using mulch is amazing," Lewis says.
He offers another water-saving tip for homeowners with lawns: Mow higher and mow less often. "If we mow higher, the taller grass blades shade the ground and less water evaporates out of the ground. Taller grass also grows more slowly."
Xeriscape landscapers place a premium on using native plants that are well-adapted to the area. Xeriscape plant lists, indicating which plants are naturally suited for a particular region of the country, are published by many local water boards.
The lists include perennials, ground covers, shrubs, grasses, and trees. "It's not like we have to pick from a tiny palette of plants," Lewis says.
"We have a lot of choice now of plants that don't require a lot of water and offer color throughout the year," says John Olaf Nelson, manager of the North Marin Water District in California. "You can design your landscape so that there's always something interesting happening in it."
The rationale for using well-adapted or native plants is practical: It reduces pest problems and maintenance hassles. Native plants are most likely to prosper with the least amount of care.
"We now have a lot more expertise in the landscape industry as to how to design a low-maintenance, good-looking landscape," Mr. Nelson says.
Initially, however, some segments of the landscape industry resisted new ideas.
An important part of the growth of xeriscape has been the education and participation of the "green industry itself - the nursery people, landscape designers and contractors," Nelson says.
Much of the controversy centers around the xeriscape principle of limiting lawns. In the beginning, "the whole turf industry was up in arms" over this idea, Lewis says.
Many homeowners are attached to traditionally large lawns and don't want to replace them with drought-resistant plants.
"Having the quietness of the lawn balancing the activity of beds works well," acknowledges Lewis. "We don't always want to just take away the lawn."
The litmus test is whether that lawn area serves a function, either practically or aesthetically, Welsh says. "What we've got to get away from is designing the flower beds and the patios - and then putting in everything else as turf, like a fill-in material."
"Throughout time, people have always created gardens," Lewis says. Now we're seeing the need for attractive landscapes that also make sense environmentally.
"We can work with nature and at the same time have fun with creating what we think are beautiful surroundings," Lewis says.