Gardening with Less Water (Storey Publishing, 2015) offers simple, inexpensive, low-tech techniques for watering your garden much more efficiently — using up to 90 percent less water for the same results. With illustrated step-by-step instructions, David Bainbridge shows you how to install buried clay pots and pipes, wicking systems, and other porous containers that deliver water directly to a plant’s roots with little to no evaporation
Water-wise gardening can reduce water demand and improve growth and yield of crops, the beauty of flowers and shrubs, and the health of the soil and landscape. Most of us are using much more water than we need, and we can all make dramatic changes in our gardens, yards, or farms that will make a difference. Cutting water use 50 percent can be relatively easy, but it’s possible to go much further. You may find your savings increase each year as you develop your skills and understanding of super-efficient irrigation and water-wise gardening. Many agriculture extension groups, garden associations, water agencies, and sustainable farming groups offer classes or online materials. Some cities and states are now offering financial incentives as well.
Keep in mind that gardening is also about climate and microclimate. What works in the low desert around Yuma, Arizona, may not work as well in Las Vegas, Santa Fe, or Atlanta. Read with a careful eye, and look for specific information for where you live. Learn from your neighbors, and take classes offered by local experts. Even if they are not familiar with super-efficient irrigation systems, they should be able to help with advice on soils, composting, crop varieties, planting, pest control, and crop timing.
Water-wise Gardening Tips
1.Give priority to the native plants from your region that are drought resistant, drought tolerant, or drought avoiding. The growing interest in xeriscape, a water-efficient landscaping method developed for arid climates, has made it much easier to find plants that will do well with very little water. Succulents often offer the best flowers for the least water. Your local garden center or nursery can help with advice and will usually sell varieties that do well in your area, but don’t restrict yourself to the handful of choices they offer. Search out the native plant nurseries and specialty growers who work with heirloom and exotic varieties. Look through the catalogs and websites of other companies that offer special heirloom and international varieties. Ask about locally developed and adapted species and cultivars. Where no locally adapted varieties are available, try heirloom cultivars from comparable climates. Ask your neighbors, your cooperative extension agent, and garden clubs what works for them and tastes best. Visit the local farmers’ markets and see what is being grown and sold.
2. Choose varieties that are dry land adapted. Many of these heirloom varieties have been selected over generations to do well with less water. Some, such as Hopi corn, have adapted with very deep, fast-growing roots. Also, crops and flowers that can be started indoors early in the season and then planted in the garden in very early spring will complete their life cycle by the time it gets really hot and dry. Trees that are very drought resistant include olives, pomegranates, loquat, macadamias, carob, and mesquite. Dwarf-type trees can also reduce water use and will do well in pots or containers. These can be surprisingly productive. Our Meyer lemon churns out delicious lemons all year long in San Diego!
3. Replace your lawn with water-conserving native plants, xeriscape, or gardens. With super-efficient irrigation, the replacement plants will use less water than a lawn. Rainwater harvesting can also provide much, if not all, of the water for the new landscape. In many areas, homeowner associations will resist or not permit lawn removal, but they may allow artificial grass to be installed. The more expensive types of artificial turf are surprisingly lifelike, but these fake lawns do heat up in the summer. Some states have realized the importance of removing lawns and have passed laws limiting the power of homeowner associations. In the West, the reality of ongoing drought has many agencies offering financial incentives to remove lawns.
4. Plant in blocks instead of rows to reduce evaporation losses and weed growth. Plants can also benefit from zoning so that plants with similar water demand are in the same area. This way, water application can be timed to meet plant needs without overwatering some plants and under watering others. In rainwater-based systems, the zoning is often done with the most water needy plants nearest to the water source. This helps ensure that when water runs short the plants that need water most are going to get it.
5. Keep your soil healthy and uncompacted so that irrigation water can move through more easily. Roots will grow denser and deeper and develop better partnerships with beneficial mycorrhizal fungi and nitrogen-fixing bacteria. Double digging to provide deep friable soil can dramatically improve crop growth and plant health on degraded compacted soils; it is best done in spring with moist soil and cooler temperatures.
6. Check your soil’s drainage. You can check drainage by digging a hole 18 to 24 inches deep and filling it with water. Fill it again the next day. If it doesn’t fully drain after one or two days, the drainage may be impaired. This may indicate that the topsoil was all removed during grading for the housing development or that one or more layers of caliche exist. In arid areas, caliche is found as a light-colored layer in the soil where the soil particles have been cemented together by calcium carbonate.A raised bed may be the best answer. In some cases you can improve drainage by deep ripping and adding lots of organic matter, sand, or, for clay-rich soils, calcium (as gypsum). Good drainage in potting mixes is also important.
7. Use mulch to reduce the evaporation of water from the soil, keep soil temperatures down, and help control weeds. Gravel mixed with coarse sand has been used as mulch for hundreds if not thousands of years in China to conserve moisture. (In a recent study, this kind of mulch reduced water loss 82 percent over 14 days; runoff decreased 95 percent during summer rains.) On a small plot, gravel can be raked up at season’s end, sieved to remove the dirt, and reapplied. Many seeds require warmer soil temperatures to germinate, so bare soil may be best when seeds are first planted in spring. Early summer is prime time to maximize mulch. For landscaping, shrubs, and trees, you can add mulch earlier.
8. Consider irrigating with greywater. Where water supplies are very short, some people use greywater from sinks, laundry, and showers to sub-irrigate crops where the water will not contact the parts we eat. (Berries, fruit and nut trees, tomatoes, and peppers are fine, but not lettuce, cabbage, or melons.) If you choose soaps and shampoos carefully, this water will not harm your plants. Cities, counties, and states may have rules governing greywater reuse. Ask first before installing a greywater recycling system to see if there are any financial incentives or restrictions.
Cities Get on Board
Some cities now make recycled wastewater available, often in magenta-colored pipes to prevent cross connections. This water is usually suitable only for landscaping but when treated to a higher standard can be used for agricultural crops.
Excerpted from Gardening with Less Water (c) David A. Bainbridge. Used with permission of Storey Publishing.