Eucalyptus Magazine / March 2010 / Sustainable Landscapes

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Sustainable Landscapes

Yards of the future

Sustainable landscaping, with its emphasis on native plants, low water usage, recycled materials, and respect for the environment, is gaining ground in the Bay Area. Yard by yard, more homeowners are planting beautiful, drought-tolerant gardens where birds and butterflies abound, and leaving thirsty lawns and high-maintenance plants behind, says Jeff Sheehan of Confidence Landscaping in Campbell.

“Most people have no idea what an appropriate landscape is,” Sheehan says. “Fortunately, nine out of 10 of my clients are easy to convince.”

What he aims to convince them of is the benefit of “sustainable landscaping”—the use of plants that look beautiful and garden materials that function well, all without requiring much water, chemical pesticides, or fertilizers.

The change to sustainable landscaping is more than an aesthetic one. With an eye toward water conservation, many homeowners are rethinking what plant varieties they want around their homes. In addition, many Bay Area residents share the belief that chemical herbicides, pesticides, and gas-powered tools harm the environment, and prefer not to use them when working in their yards.

Assess needs, rethink the lawn
Creating a sustainable yard takes input from the homeowner as well as the knowledge of an expert. What are the needs of the home-owner? Are there young children in the family who play in the yard, or an uncomfortably close neighbor the homeowner would prefer to screen out? One person’s priority might be an enclosed, private space, while another wants a productive vegetable garden. Sustainable landscapes encompass the same considerations as standard landscapes, but with the emphasis on low environmental impact, and low-cost, low-hassle maintenance.

One of the best ways for homeowners to begin creating a sustainable yard is to reduce the size of their lawns, or remove them altogether. According to Virginia Scott Jenkins, author of The Lawn: A History of an American Obsession, lawns cover 30 million acres of the United States. They consume billions of gallons of water each week, and cost billions of dollars per year in care, including money spent on pesticides, herbicides, mowers, and trimmers.

Maintaining a lawn requires hours of work each week to keep the grass looking its best. And some consider lawns an environmental liability: Gas-powered mowers pump pollution into the air, and grass clippings typically end up in landfills as trash. Replacing thirsty grass with arid-climate plantings, mulched areas, paving, or even a trampoline eliminates the need for lawn care and nixes the need for a mower.

Which plants make good lawn replacements? The list of possible trees, shrubs, and flowers is enormous, and choosing wisely depends on the nature of the site. If the area gets lots of sun, plants native to the California chaparral are good choices. A few examples are manzanita, silk tassel bush, ceanothus, salvia, monkey flower, yarrow, fremontia, buckwheat, penstemon, and California fuchsia. In areas with more shade, gooseberries and coffeeberries grow well and provide colorful berries that birds love.

Californian, Mediterranean, and Australian native plants offer a wide variety of flowers at different times of the year; with careful planning, the sustainable garden can feature something in bloom almost year-round. Shade and privacy can come from tall plants, screens, or fences. Food gardening can be integrated with the landscape to create an “edible landscape,” one where food plants combine pleasantly with landscape plants.

Turn back the invaders
Alrie Middlebrook of Middlebrook Gardens in San Jose advises clients to educate themselves about what kinds of plants belong in their gardens.

“Understand and identify invasive plants, and remove them instead of potentially valuable plants,” she says.

Ivy, vinca, pampas grass, acacia, and oxalis are a few of the invasive species that grow commonly in the South Bay. These plants dominate and eventually eradicate slower-growing, native plants, and they have little benefit for wildlife. By contrast, the native elderberry is host to hundreds of native insects, birds, and animals, providing food and shelter.

By installing plants that are native to California or thrive in this climate, Sheehan says, his clients often drastically cut the amount of water needed to maintain their yards.

“We’ve all seen sprinklers going on a rainy day, or water spraying into the gutter. People need to understand the impacts of their actions,” says Sheehan, who has been known to knock on strangers’ doors to tell them about their watering problems.

Minimize water use
“Over-watering destroys the nutrients in the soil,” Sheehan says. If nutrients are swept away, he says, then they need to be added back to the soil, which is not a sustainable practice.

The ultimate sustainable landscape is the xeriscape, which utilizes no supplemental water. As California’s climate becomes more erratic, with longer periods of dry, hot weather predicted, this method of landscaping will make sense for more homeowners. Many of the state’s native plants are naturally adapted to the xeriscape, so they are widely used in this type of design.

Accepting that summer is these plants’ dormant time, when they rest and wait for winter rain, will be an adjustment for people who expect their gardens to look green and lush all summer long. But in the South Bay, using a balance of native and Mediterranean plants ensures an interesting and varied garden even in the area’s dry summer months, says Tim Hoagland of HLD Group Landscape Architecture in Los Gatos.

Let it be
In addition to removing invasive plants and choosing new ones wisely, sustainable landscapers strive to protect healthy soil, as well as reuse existing garden materials when possible.

Sheehan says his team disturbs the natural soil as little as possible. “Digging soil alters its microbial activity,” he says. “It takes a long time for the soil to repair itself.” When soil is disrupted, plants experience stress and are less able to absorb water and nutrients. He also tries to use garden materials already at the site, minimizing the need for imports. Hoagland also applies the reuse philosophy to landcaping.

“We look at the embodied energy, or possible reuse, of the materials we use,” Hoagland says. “Things like concrete, artificial turf, imported stone—they all have an environmental impact, whether large or small. Can we use them more than once, or will they ultimately end up in the landfill? For example, paving stones can be pried up from a driveway and reused, perhaps stacked in a retaining wall, but concrete requires more energy to recycle.”

Give plants their space
Another important practice is to give new plants the room they’ll need once they mature, so homeowners need to have patience with a freshly planted landscape, says Sheehan.

“People tend to crowd plantings, because they don’t realize that these little trees and shrubs will soon outgrow their spaces. Then the homeowner spends hours trimming plants and sending the waste to the landfill,” he says. Plants that are properly spaced should reduce maintenance rather than increase it, one of the goals of sustainable landscaping.

Free from the burden of constant maintenance, homeowners have more time to enjoy the garden, relaxing and observing nature with the knowledge that they have done something positive for the environment.

Homeowners can “tread lightly on the Earth,” says Hoagland, and in return enjoy a beautiful, environmentally friendly, low-maintenance yard—the very definition of “sustainable.”