Time to ask serious questions about lawns and water.
The notion that panels of mowed grass should serve as the prime carpet within our landscapes comes to Westerners as a historical hand-me-down. The West was settled mostly by people from the Eastern United States and Northern Europe places where green grass grows so easily it just about comes with the mortgage. But every part of the populated West is too arid for green grass to grow naturally throughout the year. The map below shows why: from May through October, the West gets so little rain that grass has to be sustained with piped-in water. And lawn grass generally requires more water per square foot than anything else that we grow. Western droughts, population growth, and a water-conservative future The amount of water needed to maintain lawns began to matter with the droughts of the 70s. And droughts continue to come upon us, with last winter's precipitation well below average for much of the West. Even in a wet year, there's a limit to how much water can be stored. Since the West is the country's fastest-growing region, it seems logical that, as the population continues to grow, Westerners are going to have to conserve more water. Water shortages affect everyone. Though agriculture uses about 83 percent of California's water, homeowners, municipalities, and industry also face a future of increasing frugality with their share of this precious resource. Think about how water-greedy grass is, and then ask: do we really need all the mowed turf we maintain? You may very well decide that you don't need the unused portions enough to continue supplying the You have many options Nature and the nursery industry offer many attractive, low-growing alternatives that require only 10 to 15 percent of the water grass needs. That's the way it has worked for us at Sunset. The year before last, we replaced nearly an acre of unused lawn around the fronts of our buildings in Menlo Park, California, with five different kinds of low-wateruse ground covers. You can read about what we did and how we did it in our September 1989 issue. These days, our water-conserving ground covers-which use only a sixth to a tenth of the water the grass needed-are looking handsomer by the month, with more variety and seasonal interest than the lawns had. And they've offered us an unexpected but quite impressive dividend: they have required much less upkeep than turf, saving us a good deal of both time and dollars. Along with plants, you also have another choice: inert ground covers, including gravel, crushed rock, concrete pavers, flagstone, and brick. In the examples on the following pages, notice the close association of paving materials with ground covers, shrubs, trees, and structures-avoiding the parking-lot look you'd get if you just paved over where a big lawn had been. When you plan a low-water-use garden to replace a lawn, you have an opportunity to create a unique environment. Look at the seven lawn replacements shown on these pages and we think you'll agree-besides saving a great amount of water, gardens without lawns can be totally satisfying and useful. Each garden shown here meets its owners' needs, with a greater diversity of plants, flowers, and surfaces than before. From planning to replanting, here are tips to help you make the transition from lawn to low-water-use garden. Two Sunset books can get you started To choose plants to replace the removed lawn, consult the Sunset Western Garden Book. Its listings of drought-tolerant trees, shrubs, vines, perennials, bulbs, and annuals-with climate zones where they grow-offer you many ideas. Also check a recent Sunset book, Waterwise Gardening. It contains a detailed chapter on planning and design, and its watering chapter describes the latest advances in drip systems. The "Plants at a Glance" section fills you in on some 350 water-thrifty trees, shrubs, vines, and perennials-including ground covers. Other steps to a new landscape Now is the time to make all parts of the garden function smoothly. Check walks, drives, and entry landings. Do walkways take people where they want to go? Do people have space to open car doors and get out comfortably? A professional designer can help. The hotter your climate, the more you need to provide at least partial shade over paving or stone during hottest hours of the day to reduce heat buildup and glare (note pleasant shadow patterns on the Fresno, California, patio above right). But in cool-summer climates, the heat down in an out-of-the-way place, and keep them slightly moist (covering with plastic helps); in about a year, you'll have excellent compost. Spray hard-to-kill stoloniferous grasses while they're green and vigorously growing; use a systemic herbicide such as glyphosate. Usually, it takes two or three applications, spaced 10 days to several weeks apart, to kill the last remnants. Follow label directions precisely; spray that drifts onto green parts of other plants, including trunks of roses, citrus, and chorizia trees, can damage them. Determined composters will even use Bermuda (albeit separately); most gardeners won't risk regrowth, and discard it. In drought areas where you're sure the lawn is already completely dead, you can just rotary-till it under. Soak soil several days beforehand so it's barely moist (like a wrung-out sponge) when you till it. What about irrigation? In most cases, it's best to disconnect and cap off an old sprinkler system and start with a new drip or low-flow one. Add an anti-siphon valve to meet current codes. Just leave the old pipes in the ground. In simpler remodels, if the old pipes are sound, you can cap some heads and switch others to bubblers, drip emitters, or lowflow sprinklers. Local suppliers can probably offer parts and information. As you regrade soil or add paving, install temporarily capped risers to the new grade or install pipes (and electric wires) under paving, as needed. This saves having to undo completed work later. Consider mounds. Get ready to plant Since most lawn alternatives don't need mowing, they allow you more flexibility in contouring the site. Low mounds can discourage people, animals, and even cars from cutting across planted areas. They also give young trees and shrubs instant height, add privacy, and look more interesting than a flat expanse. The smaller your space, the lower the mounds should be to stay in scale with their surroundings. Plants on mounds are usually best watered by drip. Add header boards to keep different materials in place. Install any paving materials, and prepare soil for planting by tilling in organic soil amendments. For most soils, you need to add enough amendments to cover soil 2 to 5 inches deep. Spacing ground covers The bigger the plants at maturity, the more future troubles you cause by planting too closely. Most shrubby ground covers such as junipers, grevillea, or rhaphiolepis-mature to at least 4 feet wide, more often to 5 to 8 feet. Planted 2 feet apart, they look good at planting time. A year later, they will almost cover the soil. But in two years, they will be crowded and beginning to fight one another for survival. Crowded shrubs mound up higher than normal and are more susceptible to insects and disease. For best results in the long term, a good estimate for plant spacing is about two thirds the width of the mature plant (check the Western Garden Book or measure for yourself). That means 4 to 6 feet apart for most junipers, almost never less than 3 to 4 feet apart for any shrub. For best looks immediately, cover all exposed soil with mulch, keeping it away from woody trunks. Or, fill gaps between big, slow growers with quick, temporary, noncompetitive ground covers such as wildflowers, freeway daisies (Osteospermum), or verbena. (Don't use aggressively growing plants such as hypericum or ivy as temporary fillers.) Spacing of low, fast-spreading plants such as hypericum, ivy, or vinca is less critical. Set 6 to 8 inches apart, small rooted cuttings can close ranks in as little as 6 months; spaced I to I 1/2 feet apart, they should grow solid in 12 to 18 months. To control weeds, professionals often use a pre-emergent herbicide, alone or in addition to mulch. But a mulch alone, 4 inches deep, will eliminate most weeds and make the few that do sprout easy to pull. If you keep up with them, handpulling small areas takes about the same effort as applying chemical controls.
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|Date:||Jun 1, 1990|
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