Becoming a Model of Irrigation Efficiency

Posted on September 8, 2017 by tomkarwin

As the summer draws to a conclusion, gardeners should consider landscape installations in anticipation of the rainy season’s onset. Right now is the best time to plan new plants. The coming rains will keep them irrigated as they develop roots and prepare to bud out in the spring. The rainy season usually begins in mid-October, so we now have time to decide on new plants, find them in a garden center or online nursery, and acquire them.

Because half of California’s urban water use is for landscape irrigation, all gardeners should be conscious of their landscape’s water need and informed about the preferred ways to meet those needs. Last winter’s rains were pretty good and supported the growth of very satisfying gardens, but the long-term potential remains for water shortages.

For these reasons, this is also the right time to update your plans for water use efficiency.

California’s Model Water Efficient Landscape Ordinance (MWELO) “promote(s) the values and benefits of landscaping practices that integrate and go beyond the conservation and efficient use of water” and “establish(es) a structure for planning, designing, installing, maintaining and managing water efficient landscape in new construction and rehabilitated projects…”

This ordinance applies to new landscapes of 500 square feet or more and rehabilitated landscapes of 2,500 square feet or more when either project requires a permit.

Such large-scale projects require a detailed Landscape Documentation Package that must be signed by the responsible parties and an auditor. For detailed information, browse to the website of the California Department of Water Resources and search for “MWELO.”

Most landscape renovation projects are not extensive enough to have to meet the comprehensive requirements of this ordinance, but its thorough approach is worth informal consideration on a voluntary basis.

The key component of the Package is the appended Water Efficient Landscape Worksheet, which is used to estimate evapotranspiration, i.e., the water evaporated from adjacent soil and other surfaces, and transpired by plants, and to calculate the evapotranspiration adjustment factor (ETAF). The Worksheet guides the calculation of the ETAF which considers the major influences on the amount of water required by the landscape: plant factors and irrigation efficiency.

For residential areas, the ETAF should not exceed .55. This figure is then used to determine the Maximum Applied Water Allowance (MAWA) and the Estimated Total Water Use, which must be below the MAWA.

This explanation uses the minimum number of acronyms!

The simpler approach to efficient water use in the landscape involves two concepts. First, choose plants with lower water needs. The obvious choices are California native plants and succulent plants. Second, use drip irrigation to control the amount and location of water usage. The state provides a useful planning resource, “A Guide to Estimating Irrigation Water Needs of Landscape Plantings in California.” It’s available without cost from the California Department of Water Resources website. Search for “WUCOLS.” That one more acronym stands for “Water Use Classifications of Landscape Species.” The Guide document includes the water use needs of many garden plants, listed by both botanical and common names, and are format in PDF files with the use of software as soda pdf online.

Planning for efficient irrigation helps to conserve the state’s limited water resources, and, for the gardener, minimizes the cost of water usage and supports effective plant growth.

This planning pays off!

California’s Healthy Soils Initiative

Posted on December 3, 2016 by tomkarwin

This week, California’s Department of Food and Agriculture reported progress in implementing the state’s Healthy Soils Initiative. This matter might seem esoteric for home gardeners, but it’s worth our attention for several reasons that are listed below.

First, by way of definition, let’s review the initiative’s goals, as stated by the CDFA:

Improve plant health and yields —contain important nutrients that improve plant growth and yields.
Improve biological diversity and wildlife habitat — at least a quarter of the world’s biodiversity lives in the soil; healthy soils improve habitats and other natural resources.
Reduce sediment erosion and dust — improve aeration, water infiltration, flood management and resistance to erosion and dust control.
Sequester and reduce greenhouse gasses — carbon stored in soil reduces overall greenhouse gas emissions from agriculture.
Improve water and air quality —affects the persistence and biodegradability of pesticides and other inputs.
Increase water retention — healthy soil has the ability to hold up to 20 times its weight in water.

These goals encompass a “basket” of interconnected issues: agriculture, an important part of California’s economy; biodiversity; erosion; climate change; water & air quality; and drought. These issues are concerns of several state agencies, all of which are engaged in the operation of this initiative. Promoting interagency coordination and collaboration, which is never easy, is among the principal actions to advance this work.

The state’s 2016 budget act includes substantial funding for the Healthy Soils Program. The CDFA has defined five primary actions for carrying out its responsibilities under this program. Its recent report of progress focuses on Action #2: the identification of sustainable and integrated financing opportunities for (a) promoting greenhouse gas reductions, (b) sequestering carbon, (c) increasing water-holding capacity of the soil, and (d) increasing crop yields. The CDFA has drafted a framework for this program and will be inviting public comments beginning in January 2017.

The Healthy Soils Initiative and Program clearly target California’s agriculture industry. Why should home gardeners find this work interesting?

It addresses issues that are important for every resident of the state, and that require long-term, comprehensive strategies for effective action.
Home gardeners could (and should) adopt their own Healthy Soil goals and action plan to pursue within their respective gardens.
By adopting the Healthy Soils Initiative, California both acts constructively to improve the quality of life within the state and provides a practical model for other states and indeed for the world. Everyone has a stake in this program’s success.

The CDFA has recently updated its website for the Healthy Soils Initiative. This site offers complete and succinct information on this program. Gardeners should visit the site and consider how they could pursue an equivalent program in their own gardens. Unless the CDFA quickly produces a “Healthy Soil Initiative for Home Gardeners,” watch for it in this column. Your ideas will be welcome!

Rediscovering Eco-cultural Gardening

Posted on May 12, 2016 by tomkarwin

Gardening is a very old activity. The word “garden” has its roots in an Old English term meaning “fence” or “enclosure,” and the earliest enclosed outdoor space discovered was created about 12,000 years ago.

We are still learning about gardening.

More accurately, we are rediscovering ideas that earlier gardeners understood thousands of years ago.

One of the earliest ideas, evidently, was that a fence keeps some hungry animals from the vegetables and (later) from the flowers.

The most basic principle for successful gardening is compatibility with Nature. We are advised occasionally that humans developed instinctive behaviors, e.g., Fight or Flight, at an early stage of our history, and evolved to thrive with a diet that consisted of a combination of foods that grew naturally in our local environment.

By the same token, plants and animals evolved over long periods to thrive in specific regions, together with each other. As a result of this co-evolution, we have interdependence between plants and animals that grow naturally within a specific environment. We even have interdependence between those plants and animals and certain aspects of the environment itself.

Ancient civilizations that understood these relationships intuitively gardened—and lived—in harmony with Nature. “Eco-culture” is today’s buzzword for the connection between ecological and cultural practices.

Some aspects of the environment appear not to interact with the plants and animals: the weather, elevation, and sunlight operate under their own rules, but the soil microbiota has close relationships with the flora and fauna.

Gardening is easiest and most successful when we recognize and respect these natural relationships. Good practices include gardening organically and growing plants that are native to the local environment.

The more recent history of gardening, however, has included many attempts to rewrite Nature’s rulebook. For example, as people traveled the globe, they added plants from exotic environments to their gardens and developed adaptive practices, including irrigation systems, greenhouses, and indoor gardening.

Also, as gardeners desired plants that would grow faster or larger, taste better, or look better, they developed hybridizing methods, fertilizers, and pesticides.

Such departures from Nature’s ways are often successful in achieving certain objectives, but they often have negative consequences, as well.

The clearest downside of attempts to “fool Mother Nature” is that gardening requires more time, energy and expense. If you find gardening to be burdensome, try converting to plants that are native to your environment.

When large-scale, commercial gardening (“agriculture”) adopts new technologies, the disruptions of Nature’s processes also grow larger in scale. Widespread applications of synthetic agricultural chemicals are damaging the soil biota, are poisoning the soil, killing birds, bees and butterflies, contributing to climate change and threatening our health.

Historically, ecological traumas began with the Industrial Revolution and accelerated in the 1940’s (with at the start of World War II), particularly in uses of synthetic chemicals.

Today, a growing number of non-profit organizations are sounding alarms about these practices and advocating alignment with Nature’s ways. Consumers increasingly demand organic foods, and intuitively resist genetically engineering foods. These groups and individual gardeners are rediscovering eco-cultural gardening.

Our roots are showing!

More to come: links to consumer-oriented non-profit groups related to eco-cultural gardening.

Here’s a related article (with an inappropriate title), “The dirty little secrets of a Native American garden,” from the San Francisco Examiner.

South African Flora

Posted on September 16, 2015 by tomkarwin

As California’s drought stretches into the future, the plants of Earth’s five Mediterranean climate zones attract gardeners’ interest and soon earn their appreciation. Many of these plants are fine additions to the landscape, offering beauty, fragrance and benefits for garden fauna as well as easy cultivation (with some exceptions) and environmental friendliness.

In today’s column, with our feet on the ground, we have an overview of the flora of one of these “summer-dry” zones: South Africa.

This relatively small country’s Mediterranean climate zone is the very small and extraordinary Cape Floristic Region. As background, botanists have identified six Floristic Regions (floral kingdoms) of the world. These are regions with distinctive plant life. The Cape Floristic Region, by far the smallest of the six, is noteworthy for very high diversity of plant life, with over 8,000 species, and very high endemism: nearly 70% of the plant species are native to the Region and nowhere else.

Much of the Region’s botanic diversity grows on the fire-prone shrub land called fynbos, which is roughly comparable to California’s chaparral. Both of these two shrub lands have shrubs with hard leaves, closely spaced on their stems.

The fynbos is the home for numerous small shrubs, evergreen and herbaceous plants, and bulbs, many of which are in three plant families.

The Protea family (Proteaceae), which includes 80 genera and 1,600 species, all in the Southern Hemisphere, and mostly in South Africa and Australia. The family name comes from the name of the Greek god Proteus, who could change between many forms. The adjective “protean” (changeable, versatile) has the same root. Plants in this family have a great diversity of flowers and leaves.

The popular South African genera in the Protea family include

Proteas (sugarbushes), which come in a range of heights, from three feet to nine feet, with unique compound flower heads (correctly, inflorescences) in pink or sometimes red.

Leucospermums (pincushions), most reach four-to-five feet tall, with yellow, orange, pink or red flowers.

Leucadendrons (conebushes), various species grow from three-to-eight feet tall; the striking silver tree (L. argenteum) reaches 25-to-40 feet tall, with “soft, silky, shimmering, silvery-green-gray, lance-shaped foliage.” The cone-shaped flowers typically are surrounded by petal-like bracts, often combining red and yellow colors.

Australia is home to several genera of the Proteaceae, including banksia, grevillea and hakea.

The Cape heaths (Ericaceae) include some 660 species that are endemic to South Africa, and are often called winter (or spring) heather. Another 40 species, including summer (or autumn) heather are native to other parts of Africa the Mediterranean basin and Europe. Most of the Cape heaths are small shrubs, from eight inches to sixty inches in height, with attractive tubular pink flowers throughout the year.

The Cape reeds (Restionaceae). The genus Restio includes 168 species in South Africa. Various species of Restio grow from one-to-ten feet tall, with tiny flowers grouped in spikelets that comprise inflorescences. Other genera in this family of perennial, evergreen rush-like flowering plants are found throughout the Southern Hemisphere.

To view photographs of South African plants, serve the web for the plant’s botanical name and click on the menu option for images. Better yet: to experience the real presence of these plants, browse to arboretum.ucsc.edu, navigate to Visit/Gardens and Collections/South Africa, and tour the Arboretum’s South African collection in person. You could become inspired to bring South Africa’s botanical bounty into your own garden.

Restoring Soil

Posted on July 12, 2015 by tomkarwin

Several people commented on last week’s column on the carbon cycle. All endorsed the concept of restoring garden soil, to support its natural ability to sequester carbon.

One reader had questions about how to go about restoring garden soil. This is a Big Topic and you, good reader, might have your own questions, but you also might share his interests. My brief responses are below. Visit gardening.com for more details, including plant suggestions.

Q. Plow the grass under?

A. Losing the thirsty lawn is a good first step, because such monocultures are not appealing to wildlife. Plowing, however, could both promote re-growth of the grass and bring dormant weed seeds to the surface. A better approach is to kill the grass over several sunny weeks by covering it with clear plastic (solarization), or with newspaper or cardboard (smothering).

For information on Soil Solarization for Gardens & Landscapes, visit the University of California’s Integrated Pest Management webpage on the topic. The presentation emphasizes pest control; in this context, unwanted turf grass amounts to a pest.

The California Native Plant Society has Detailed lawn removal advice.

Q. Plant different grass?

A. Yes! California native grasses can provide the basis of an attractive meadow, which is more casual than a manicured carpet of turf grass. A meadow has unique aesthetic appeal; supports a variety of wildflowers and wildlife; requires little water, infrequent mowing, and no chemicals; and helps to restore the soil.


JACQUELINE RAMSEYER — BAY AREA NEWS GROUP

Lily Baker’s front yard in San Jose
features a native grass lawn.
California native grasses help restore the soil.

For information on several California native grasses, visit the Tree of Life Nursery’s web page, “Masses of Grasses.”

A very good book by Carol Bornstein, David Fross, and Bart O’Brien is Reimagining the California Lawn: Water-conserving Plants, Practices, and Designs (2011).

Q. Grow more trees?

A. Absolutely! Trees and large shrubs are attractive additions to the landscape, valuable participants in the carbon cycle, and welcomed by all forms of wildlife. Invest a little research to select trees will thrive in your climate, and grow to an appropriate size for your landscape. Again, California natives are good choices.

A good introduction to California native trees and larger shrubs is available from the non-profit Nipomo Native Garden, which has produced a web page, “Native Trees for Landscaping and Wildlife.”

Q. Eliminate ground cover in favor of something with deeper roots?

A. Ground covers are any plants that hug surface or rise to any height up to four feet. Most importantly, they protect soil and soil microbiota from baking in the sun, or eroding. During the fall and winter, plant seasonal cover crops that draw nitrogen from the air and store it in their roots. Examples of such “nitrogen-fixing” plants include peas, beans, and clover. In the spring, before your cover crop sets seed, till the plants under to decompose and release their nitrogen into the soil to support the growth of other plants.

Deeper roots mean better drought-tolerance: deep-rooted plant can find moisture far below the surface. Such plants are generally preferable in the landscape, all other factors being equal.

The depth of roots varies among plants, reflecting adaptation to the plant’s environment. Among weedy grasses, for example, Annual Bluegrass (Poa annua) has roots only about right inches deep, while Bermudagrass (Cynodon dactylon) can grow to 60 inches deep in search of water.

Infrequent, deep irrigation encourages all plants to develop deep roots and drought tolerance. A common error with automatic irrigation systems is to schedule frequent, brief periods of watering. This practice encourages shallow roots, ultimately increases overall water usage and leaves plants vulnerable to dry periods.

Q. Shallower roots?

A. The advantage of shallower roots is that plants growing in arid climates have immediate access to occasional rains. Succulent plants have adapted to such conditions by developing shallow roots and the ability to store scarce moisture in their leaves, stems or roots. For this reason, gardeners often appreciate succulent plants for both drought tolerance and landscape appeal.

The New California Garden, which we envision here, features meadow grasses and succulent plants: a good time to start is now.

Gardening to Reverse Climate Change

Posted on July 3, 2015 by tomkarwin

The threat of climate change has become a concern among scientists, environmentalists and gardeners (who might wear all three of these hats, of course). In the search for solution to this problem, these three interested parties have common ground, as we explore in this column.

As background, our climate is changing as a result of a disruption of the Carbon Cycle.

On Plant Earth, a fixed amount of carbon cycles through different forms: liquid, solid, or gas.

Carbon enters the atmosphere from several sources, including respiration of animals and plants, decay of animals and plants, eruptions of volcanoes, and releases of dissolved carbon dioxide (CO₂) from the oceans.

Plants absorb carbon dioxide (CO₂) from the atmosphere, and use photosynthesis to release oxygen back into the atmosphere and convert carbon into sugars that support the plant’s above-ground growth. At the same time, up to 40% of the CO₂goes to the plant’s roots, to feed soil microbes. The microbes assist the plant to acquire nutrients through its roots, and lock (“sequester”) carbon into the soil for very long periods.

The Carbon Cycle supports Earth’s climate and enables the growth of plants and literally all other living things.

Credit: NASA/Globe Project

In the diagram above, notations in blue indicate pools of carbon and notations in red indicate fluxes of carbon, both quantities are measured in petagrams.

This complex natural process balances the amount of carbon in liquid, solid and gas forms. Vast amounts of carbon are stored in the soil and fossil fuels, and much smaller amounts are stored in the atmosphere, the oceans, and plants.

During the Industrial Revolution (1760 to c. 1830), humans began burning fossil fuels, cutting down forests, draining wetlands, converting grasslands to large-scale crops, paving paradise, and applying synthetic chemical fertilizers and pesticides. These activities have been disrupting the Carbon Cycle and altering this important balance.

The consequences include degraded soil with reduced ability to capture carbon, an excess of carbon in the atmosphere, the acidification of the oceans, and other effects, none of which are beneficial to living things (including us).

The broad term, climate change, encompasses all these negative effects.

Restoring the natural Carbon Cycle could reverse climate change.

Restoration requires feeding the soil with organic matter and planting cover crops to protect the soil from temperature extremes and erosion. In short, the solution is based upon regenerative, organic agriculture.

This strategy must be employed on a global scale, but we all should understand the Carbon Cycle and support this process of soil restoration in our own gardens and in our individual contributions to relevant public policy. Substantial private interests are invested in fossil fuels, “conventional” monoculture agriculture that depends upon synthetic chemicals, and other industrial methods that are changing our climate. They can be expected to resist this strategy of working with nature, so eventual success requires our vision and long-term commitment.

Each gardener could participate first in his or her own garden. That would be a fine way to celebrate our independence from, in this context, commercial interests.

Continue reading →

Rain Gardens – Advanced Water Conservation

Posted on June 15, 2015 by tomkarwin

Most gardeners have learned that large percentages of residential water usage occur outdoors, mostly as a result of irrigating lawn grass and other plants, and have adopted water-saving practices: replacing thirsty lawn grass with naturally drought resistant perennial plants, especially California native plants, using efficient drip irrigation, and mulch. These strategies involve relatively low expense, depending on implementation.

Some gardeners have gone to the next stage of water conservation, which includes water catchment and grey water recycling. These strategies require equipment, and its installation, both of which could lead to some initial expenses. A 5,000-gallon water tank, for example, would be a substantial investment, but one pays off through long-term water savings or even fire protection.

Today’s column introduces percolation ponds as another stage of water conservation.

When we are fortunate enough to have rain, much of the water from roofs and paved areas runs to storm drains, which in the Monterey Bay area lead eventually to the sea. An efficient storm drain system avoids flooding, but often delivers pollutants into the ocean. A better approach is to direct the runoff to the soil, which filters the pollutants and leads the water into the aquifer.

This approach involves the development of a percolation pond, which is simply a low area that collects and holds runoff so that it percolates into the ground.

The principal objectives for percolation ponds are to filter runoff to minimize pollution, recharge local groundwater, and conserve water.

To include a percolation pond in your garden, find a naturally occurring low area (or create one) that is at least ten feet away from your home and any existing septic field. This separation is needed to avoid having water migrate towards your foundation, or to interfere with any utilities close to the house.

A rain garden by a driveway in Pacific Grove. Credit Dona Johnsen Landscape Archietcture

A rain garden away from the (east coast?) residence. Credit: EPA:gov

The percolation pond should have good drainage, so that it holds water for no more than forty-eight hours. A retention pond, by contrast, holds water for longer periods, and could be designed as a water garden or bog garden.

Determine the surface area of the percolation pond to reflect the surface area of the capture area and the soil type. For example, multiple the surface area of your roof by 20% for sandy soil, 33& for loamy soil, and 45-60% for clayey soil. If you are creating a percolation pond, the bottom layer ideally should consist of about 60% sand, 20% compost and 20% topsoil. This composition would provide effective filtering of the runoff.

Then, adjust downspouts or a sump pump outlet to direct the water into the percolation pond. Depending on the situation, a bioswale could be used to direct the runoff to the percolation pond. A bioswale is a drainage course with gently sloped sides (less than six percent) and filled with vegetation, compost and/or riprap.

In areas that receive regular rainfall, the upper layer of the percolation pond can be planted with deep-rooted perennials, which can flourish under occasional deep soaking, followed by relatively dry periods. These features are called “rain gardens.”

In California, where we need to protect and restore our aquifers, and have current drought conditions, the upper layer might emphasize decorative stones, which can slow the flow of water that might otherwise overflow, and promote percolation. California native plants, once established, would do well in a percolation pond, and also provide both an attractive appearance and environmental benefits. Continue reading →

Designing a Drought-tolerant Landscape

Posted on April 24, 2015 by tomkarwin

When planning your garden for the long term, today’s important considerations include drought tolerance. Gardeners should be open to changing their gardens from time to time, as ideas change, new plants attract attention and—let’s face it—some older plants move to the compost heap in the sky.

Still, when we must anticipate prospects for long-term drought, it makes sense to base your landscape design on plants that can thrive without lots of water, or even regular irrigation.

Landscape design can be a challenging enterprise, but also could be quite approachable, given planning ahead and narrowing your focus. Assuming that you wish to change your current landscape from thirsty to drought-tolerant, or from boring to interesting, here is one path for a short distance between your present and future gardens.

First, select your target area. This might be all of a smaller yard or a high priority, not-too-large section. The front garden might be a good candidate.

Then, study the area’s characteristics: exposure to sun and wind, soil texture (sand, clay, loam), and topography (flat, sloped, hilly). This will determine which plants would be appropriate for your garden’s conditions.

Very important: choose a theme to guide plant selections for your new landscape. A theme of well-defined, limited theme will lead to study of plants that meet your criterion and add to the character of the landscape.

Plenty of plants are drought-tolerant, particularly plants from the five Mediterranean (or summer-dry) regions of the world, and succulents. For this model approach to design, we focus on California native plants; an even better theme would be plants that are native to your local plant community. California’s native plants have evolved to succeed in the soils and climates of their native growing grounds, and to enjoy symbiotic relationships with the local flora and fauna.

Secure ready access to at least one good reference book. Several good choices are available, but here is my short list:

The New Sunset Western Garden Book, 9^th Edition (2012), edited by Kathleen Norris Brenzel;
The Sunset Western Garden Book of Easy-care Plantings (2015), edited by Kathleen Norris Brenzel;
Designing California Native Gardens: The Plant Community Approach to Artful, Ecological Gardens (2007), by Glenn Keator and Alrie Middlebrook; and
Growing California Native Plants, 2^nd Edition (2012), by Marjorie Schmidt and Katherine Greenberg, with illustrations by Beth Merrick.

Select a small number of plants, for development of clusters or swaths of the same plant for optimum visual appeal and design coherence. Most gardener designers favor landscapes with plant groups or repeats, and avoid collections of isolated single specimens.

Check out local garden centers and nurseries to locate good inventories for your thematic design. Just about any plant is available by mail order, but the more common California native plants should be readily available from local sources.

click to enlarge

The plant in the photo is the California native bulb, Brodiaea californica, which has the common name, California Cluster Lily. Brodiaea plants once Triteleia plants, which have been identified as a separate (but related) genus.

Here are the botanical and common names of short lists of well-liked California native plants for a drought-tolerant landscape that has good exposure to the sun.

Trees: Arbutus (Madrone), Aesculus (California Buckeye), Quercus (Oak)

Taller Shrubs: Ceanothus (California Lilac), Rhamnus (California Coffeeberry), Rhus (Lemonade Berry)

Shorter Shrubs: Arctostaphylos (Manzanita), Artemesia (California Sagebrush), Baccharis (Dwarf Chapparal)

Perennials: Dudleya (Live Forever), Penstemon (Beardtongue), Salvia (Sage)

Bulbs: Allium (Onion), Brodiaea (Triteleia), Calochortus (Mariposa Tulip)

Groundcovers: Epilobium or Zauschneria (California Fuchsia), Eriogonum (Island Buckwheat)

All of these plants require watering after planting and until they are established. Such variables as soil texture, air temperature, and rainfall will determine the amount and frequency of watering, but the objective is to maintain soil moisture until there any danger of wilt has passed. Once the plants are well rooted, they will benefit from being watered during seasonal growth periods, but will survive nicely on their own during our future drought.

To learn more about the plants suggested above, check any of the books listed, or other general reference garden books. Most good books will provide important information such as mature size of the plant (always important in planning a landscape).

Another approach is to enter the botanical name in a search engine, e.g., Google.com, and click on “Images.” This will yield numerous photos of the plant, often showing considerable variation within the genus.

Gardening during Drought

Posted on April 20, 2015 by tomkarwin

Californians are agonizing over our severe drought and its probable future. Those going through the greatest stress are homeowners maintaining verdant lawns and gardens in southern California’s deserts, farmers using 80% of the state’s surface water, and policy makers working to move the state’s burgeoning population toward life styles and businesses that use our limited water wisely.

This will be a lengthy slog.

The good news for Monterey Bay area residents is that we have already made excellent progress in reducing water usage to the target level, which is 25% below the usage of February of 2013.

We all need to conserve more to reach that target, but not nearly as much as people in southern California, especially in desert areas, where water usage is double the state average.

Growing grass and common perennial plants in sand unavoidably requires unusual cultivation methods, including lots of water. Such gardening ignores the first rule of gardening: right plant in the right place.

The primary strategy for drought-tolerant gardening, then, is to grow plants that are native to your own patch of land. The corollary strategy is to grow plants that are similar to plants that are native to your site. For the Monterey Bay area, this means plants from the world’s regions with a summer-dry climate. These include (if you need yet another review) the Mediterranean basin, South Africa, Chile’s central coast, Australia’s southwestern coast, and of course, much of California, especially the central coast region.

Keep in mind that each of these regions includes a range of microclimates, so it is still wise to know the particular conditions within your garden, and to favor plants that thrive in those conditions. That is the crucial method for low-maintenance gardening.

I have just received Sunset’s latest book, which addresses this point in a timely, effective and attractive manner. The Sunset Western Garden Book of Easy-Care Plantings has chapters on Gardens, Beds and Borders, Succulents, Groundcovers, and Containers. Other sections provide an overall introduction and seasonal tips.

Click to Open

Kathleen Brenzel edited this book, and has edited several earlier books that merit a prominent place on California gardeners’ bookshelves. This new book includes advice from such experts as John Greenlee and Robin Stockwell, who know all there is to know about grasses and succulents, respectively, and who have shared their knowledge with gardeners often over the years. During Robin’s 2014 Succulent Extravaganza, for example, I enjoyed John’s presentation of a companion planting of grasses and succulents.

California’s drought results from the combination of several factors: cyclical weather patterns, climate change, population growth, and agribusiness expansion. It is a complex picture, to be sure, and avid gardeners need to adapt to changing conditions.

My initial scan of The Sunset Western Garden Book of Easy-Care Plantings impresses me as a good source of guidance and inspiration for that adaptation. I welcome the opportunity for learning from each chapter, and anticipate enjoying the experience, which surely will motivate even more sustainable gardening.

The New Normal for Gardens—Lose the Lawn

Posted on April 12, 2015 by tomkarwin

Earlier this month, Governor Jerry Brown issued an executive order mandating water use restrictions. This order requires California’s 400 water supply agencies to restrict water uses to achieve an overall 25% reduction, and monitor compliance with those restrictions..

The restrictions will have many impacts. Here, we consider only the impacts on small-scale gardening at residences and businesses. At another time, we’ll get to commercial agriculture’s water usage, which equals 80% of California’s developed water.

Studies have shown that 30-50% of residential water use occurs outdoors. Uses include washing cars and filling pools and fountains, but most outdoor water usage is intended to maintain the growth of plants, particularly lawn grasses.

If the current four-year drought continues for ten years or longer, as weather scientists have projected, gardeners should plan for the “new normal” for their gardens.

This is not the time to install artificial turf, learn to love the parched look, or pave your yard. There are better options.

The first step would be to remove the water hogs in your garden. These might include plants from tropical climes. For example, I have a long fascination with the Chilean Rhubard (Gunnera tinctoria), a riparian plant with enormous leaves. My garden once had one of these plants, but it dried out.

Here is a fine example of a clump of Chilean Rhubarb near a pond in a large garden in Santa Cruz.

Click to Enlarge

The next step would be to lose the lawn. A well-kept lawn consumes a lot of water, fertilizers and pesticides, plus the lawn owner’s time and money. Two-cycle lawnmowers also generate noise and air pollution.

In return, most lawns provide a green vista—or at least a resting spot for the eye—but receive very little actual use. Lawns used to symbolize status, but that was when only the wealthy could afford groundskeepers wielding scythes. The 1830 invention of the lawnmower transformed the lawn from status symbol to an easy option for many homeowners and an obsession for a few.

Now, our governor has said, “The idea of your nice little green lawn getting watered every day, those days are past.”

The plan for losing the lawn will vary with the size of your greensward. A small patch could be converted to a new reality in one go. A larger area might better be reduced incrementally, to spread the effort and the design issues over two or three years.

The first step should be to plan for replacing the lawn grass with another ground cover that would require much less water. It is all about the strategic selection of plants. This individual design decision could focus on meadow grasses, wildflowers, or drought-tolerant plants, e.g., California natives or Mediterranean climate plants. Some people have opted for cacti and succulents, which can be very interesting, but that’s a challenging move, design-wise.

There are many very attractive possibilities for a drought-tolerant landscape. Visit ongardening.com for resources to help with this planning.

Then, remove the grass. This can be done with solarization: over several weeks, a plastic cover uses the summer sun to heat the grass to extinction.

The operation of a sod cutter, probably rented, is much faster, but this method could remove enough soil to require importing topsoil.

In any event, avoid killing the grass with chemicals, which are not good for gardens. Also, avoid rototilling the soil, because that will bring buried weed seeds to the surface. A rake would be the preferred tool to smooth the soil.

Once the grass is gone, install the landscape you have designed. After a couple years of planting, watering and inevitable weeding, you will have a landscape that will survive during the coming drought years with minimal care, and look great.

Once you have made the decision to replace a traditional lawn with a drought-tolerant alternative, you can consider several options. Here are resources to explore:

Full disclosure, the Lose the Lawn website was created by a friend, Alrie Middlebrook, owner of Middlebrook Gardens. It has been available for quite a while, and is more relevant than ever today.

Sunset Magazine web resources includes 24 Inspiring Lawn-free Yards.

An excellent book on this subject is The American Meadow Garden: Creating a Natural Alternative to the Traditional Lawn, by John Greenlee and Saxon Holt (2009).

An eloquent call for California native plants is found in Reimagining the California Lawn: Water-conserving Plants, Practices and Designs, by Carol Bornstein and David Fross (2011).

A best selling book, Lawn Gone!: Low-Maintenance, Sustainable, Attractive Alternatives for Your Yard, by Pam Penick (2013), provides a new look in book title punctuation.

A search of Amazon.com for “lawn alternatives” or “drought-tolerant landscaping” will yield several additional titles for books that you might find in a local library or bookstore. There’s no shortage of ideas!

Finally, you might have heard that southern California residents so far this year have a poor record for reducing their water usage, compared to people on the central California coast. Here’s an image that provides a clue for that failure to cut back on landscape irrigation. This shows a part of Rancho Mirage, which is between Palm Springs and Palm Desert.

The grey areas are sand! If you believe the drought is a hoax, you might be interested in living on this human-created oasis. Contact Magnesia Falls Real Estate, which has this photo on its website. (An even more dramatic aerial photo of this community is in the current issue of Time magazine.