Despite the increasing number of "green" architects and interior designers--professionals who work with a health- and eco-friendly approach--the notion of "green" landscape design still raises eyebrows, Osaka says.

"If it's outdoors, how can it not be green?" is the common response Osaka gets when describing her work to others.

There are all kinds of toxins in the landscape, Osaka says, which can have a major impact on human health and the ecosystem.

"It's what you drink, what you breathe. It's what kids play in," she says.

Environmental consciousness and organic gardening have always been a significant part of the former engineer's life. Once in the computer industry, Osaka received a certificate in landscape architecture from the UC-Berkeley extension program in 1999. She briefly thought about working in a firm but knew that it might limit her ideas about sustainable landscaping.

"I just couldn't do it," she says. "I felt that I needed to go the environmental track."

In the nine years since she's set up her own business, Osaka acknowledges it hasn't been easy promoting her cause. She cites a number of reasons for the problem. There is a prevalent misconception that anything related to landscaping means "green," she says. The other hurdle is contractors. Most have been using the same materials and techniques for years and are reluctant to change.

However, several years ago, Osaka met Ryan Marlinghaus and became acquainted with his Cupertino business, Cal Earthcare Landscaping. The company's services range from installing environmentally friendly irrigation systems to planting and maintaining organic gardens.

Because his earth-friendly approach makes Marlinghaus and his business a rare commodity, Osaka has worked on numerous projects with him over the years. The fact that he's open to trying new things is a big plus, she says.

"I need someone with an open mind that's willing to experiment," she says. "That's what we're all doing."

While environmental and human well-being are the ultimate goals of sustainable landscape design, the conservation of resources is at the heart of every project.

"Any new landscape is going to require new energy and consumption," Marlinghaus says.

That's why maximizing the assets already on a property--such as the existing plants, trees and other yard materials-- helps to minimize the waste that ends up in the landfills. Osaka and Marlinghaus say using and reusing what is already available is the main principle that guides sustainable landscaping professionals.

"We do a lot with recycling," says Osaka, who over the years has become creative in her methods of reusing available materials.

Three years ago, for example, while working on the San Jose yard of Cathy and Muneer Waheed, Osaka transformed torn-out concrete from the driveway on Valpico Drive into stepping stones.

Unlike the previously impermeable layer of concrete, which caused water to run off, the stepping stone paving allowed water to seep into the ground because the stones were set in gravel. Porous paving is a huge issue in sustainable landscape design, Osaka says, because it allows underground aquifers to be refilled.

Osaka also educated the Waheeds on non-toxic materials, the use of which was a high priority for the environmentally conscious family, Cathy Waheed says.

Osaka told them to avoid chemically treated materials, such as products coated in wood and injected with chromated copper arsenate--outlawed by the U.S. Environmental Protection Agency three years ago. She also warned them about irrigation piping treated with polyvinyl chloride, which leaches toxins into the ground. These chemicals affect the quality of drinking water and contaminate the soil, Osaka says.

Other hazards include fertilizers, pesticides and herbicides, which can easily get into the sewage system and run into the Bay, endangering marine life.

While pesticides and herbicides should be minimized or better yet, eliminated from use, Osaka says simply recycling food and garden waste is a great alternative to fertilizers.

"It's amazing how much compost you can get--and it doesn't take turning the pile every week," she says.

Aside from toxins seeping into the groundwater and earth, Osaka says irresponsible irrigation is another environmental concern frequently addressed by sustainable landscaping professionals. One problem is the controllers on sprinkler systems are often set inappropriately. This leads to sprinklers running full blast during a rainstorm or watering so much that there is runoff.

"As soon as you see it running down the street, that's waste," Osaka says.

She recommends homeowners adjust their controllers at least four times a year or install drip irrigation systems. The latest technology, she says, is subsurface drip irrigation, which applies water directly to the root.

Just recently Osaka consulted Marlinghaus' services to install a subsurface irrigation system in the backyard of her client Louise Robinson. The San Jose resident says she couldn't be happier with the results.

"I have the best grass I've ever seen in my life--it's so green, it's amazing," she says.

While lawns, with their high demands on irrigation, fertilization and weekly mowing, aren't exactly considered environmentally friendly, Osaka says they do make for an outstanding play surface for children.

But people considering lawns primarily for decorative purposes have more eco-friendly options, such as native shrubs, which require minimal maintenance, she says.

"The right shrub can require no water at all, all summer long," she says.

Because plants native to California do well in poor, dry and rocky soil, they need little fertilization and watering, Osaka says. This makes them an essential resource in sustainable landscape design.

"In California we have 6,000 species of native plants," she says. "Three thousand of those are in no other place in the world. There's just no excuse for not using native plants."

Robinson knew from the beginning that she wanted to use only native plants, and Osaka introduced her to a variety of plants she had never heard of before, she says.

"A lot of them are really pretty," Robinson says. "It's not just cacti."

Besides being more environmentally responsible, a native garden also fosters a healthy eco-system likely to attract a number of species such as hummingbirds and butterflies, Osaka says. And clients are happy with the uniqueness of their backyards.

"You get a landscape that's not the typical boxwood hedge, birch, lawn," she says.

Cathy Waheed says her backyard is brimming with plant and animal life since it was put in three years ago.

"We really enjoy it," she says. "It looks good and it has a different feel to it."

Robinson adds that opting for sustainable landscaping also creates a distinctive garden atmosphere. And her yard is a testament to that creativity, with plants that were mulched and reused, concrete that was recycled for pathways, and the poured earth wall in her front yard.

For more information on Sherri Osaka and Sustainable Landscape Designs, call 408.264.7427, email sdosaka@sustainable-landscape.com or visit www.sustainable-landscape.com.

To contact Ryan Marlinghaus at Cal Earthcare Landscaping, call 408.871.2792 or email ryan@earthcareland.com.

Information on creating
sustainable gardens

Native Revival Nursery

2600 Mar Vista Drive, Aptos

831.684.1811

www.nativerevival.com

Yerba Buena Nursery

19500 Skyline Blvd., Woodside

650.851.1668

www.yerbabuenanursery.com

Larner Seeds

www.larnerseeds.com

California Native Garden Foundation

www.cngf.org

For information on drip irrigation:

Urban Farmer Store

2833 Vicente St., San Francisco

415.661.2204

www.urbanfarmerstore.com

Information on non-toxic pest control:

Peaceful Valley

www.groworganic.com

Information on paving, salvaging,
recycling:

Central Concrete

755 Stockton Ave., San Jose

408.293.6272

www.centralconcrete.com

San Jose Construction and Demoli-
tion Recycling

www.sjrecycles.org/business/cddd.htm