Keep off the grass: New techniques in irrigation conserve water in the Santa Monica Library courtyard, while some plants do it naturally. (Photos by Darcy Hemley)
Lawns are the SUVs of the garden world. The lush suburban yard, the SoCal American dream, requires inordinate amounts of water, not to mention time spent tending and manicuring. It embodies the arrogance of trying to create mini-oases in a desert climate. But recently, conservation-minded folk have been catching on — trading in their Navigators for Priuses, swapping their velveteen grass carpets for some less-thirsty and wilder-looking alternatives.
“If people are interested in expanding their vision, we like to consider other types of grasses, like buffalo and grama,” says Stephanie Psomas, vice president of Pamela Burton and Company Landscape Architecture, “or Carex — that’s a sedge which can go through a brown cycle and is reddish in the summertime.” Psomas also notes that you should avoid constant mowing, because it keeps the real shape and character of all types of grass concealed. Letting a native species of sedge grow to its full potential gives new seasonal variety and vitality to your garden. Sedges are hardy plants; once firmly rooted, they can handle a lot of foot traffic and need water only once a week. Some varieties even flower; you can add a splash of red to your yard by planting the Texas grass Muhlenbergia capillaris. For added drama, you can create an “herb lawn”: an aromatic field of chamomile and thyme, or tarragon and basil, which not only smells nice and attracts passersby, but also serves an alimentary purpose.
Psomas designed the landscaping on the Santa Monica Library gardens, which was awarded the 2006 Sustainability Award by the Los Angeles Business Council. She offers some other suggestions: “Rather than depend only on the California natives — which we love — we need to expand our palette to Mediterranean materials,” she explains. Trust in history and go with the ultimate survivor, the olive tree, renowned for its sculptural majesty and striking shadows. Once established in the ground, olive trees rarely need watering, save for dusting off urban detritus. Although it’s hard to forgo fresh produce, most olive-tree owners opt for the fruitless varieties (Swan Hill, Little Ollie, Majestic Beauty), for maintenance reasons but also because rotting olives attract flies. Just draw on the imagery of Greece, South Africa, Australia, Italy and Tunisia — places that have climates similar to California’s — in creating your sustainable-landscape fantasy.
And where you plant is just as important as what you plant. “Place deciduous trees, which lose their leaves in winter, on the south side of your house,” Psomas instructs. “That way, in the summertime, the trees have all their leaves and provide shade, while in the winter, the lack of leaves warms up the house.” This is also a nice way to bring your garden into sync with seasonal shifts and enhance its overall climatic and local “authenticity.”
Conserving water is crucial to “green” yards. During storms, rainwater that could sustain a garden usually gets funneled to the driveway and then to the street, where it picks up dirt and noxious chemicals on its way to pollute the ocean. This is known as urban runoff. Modern landscape design calls for containing as much water as possible on the lot itself, via the use of bioswales, mechanisms for directing water away from paved areas. Basically, the strategy is to build trenches around the plants that need water and fill them with gravel, so that the plants absorb water without displacing the surrounding soil when rain hits: “The entrenched stones let the water percolate from the paved area in the stone trench, and then percolate into the earth.” You can tier your garden so that higher trenches overflow into lower trenches; successful gardens do not flood, even during very wet storms. Psomas warns that, in the L.A. area, one should first test the soil’s percolation rate — how much water it absorbs — because nonabsorbent clay soil, characteristic of certain neighborhoods, renders a bio-swale unviable. If you have a little more money to spend, you might consider a gray-water recovery system, which recycles nontoilet household-use water for irrigation; over the long term, you’ll save more money than you initially invested. Psomas advises that you “zone plant-material placement by water use.” In other words, don’t combine plants with different water needs, like olive trees and geraniums. Then you can install a timer and drip-irrigation system, and won’t need to worry about watering.
After you’ve opted for wild sedges, and you’ve built custom bioswales, you don’t want to spray poison on your healthy, sustainable lawn! If you’ve got a pest problem, take advantage of nature’s processes and apply biological controls wherever possible. At Home Depot and most other garden centers, bags of live ladybugs — a predator of aphids — are available for purchase. Be sure to transfer the bugs to a more cavernous enclosure (use plastic tarp, a tent or netting) before releasing them into your backyard: They need to get their ya-yas out and fly around before settling down. Many forget this step and lose all their ladybugs within a day.
Finally, the simplest step to help your garden grow involves a small compost bin next to your sink. Keep it covered and save any organic material for it. “If you separated out all of your trash properly,” my green-savvy former Berkeley roommate reminded me, “the things you’d throw away to the landfill would fit in a tiny container; most of it would go in the recycling or compost bins.” Using compost in our small yard gave the previously bleak plants a new lease on life, with nutrients coursing through the soil as though we had buried a genuine carcass back there.
For other nonthirsty options, Psomas recommends San Marcos Growers, up in Santa Barbara, a “really terrific source of drought-tolerant plant material.” (125 S. San Marcos Rd., Santa Barbara, 805-683-1561 or www.smgrowers.com.)
The city of Santa Monica, one of the greenest cities in the U.S., provides a great online guide to urban runoff: http://santa-monica.org/epd/residents/Urban_Runoff/urban.htm.
For more on water-recovery systems, log on to www.water cache.com.
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