Designing a Drought-tolerant Landscape

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, 9th 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, 2nd 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.

Brodiaea, California Cluster Lily

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.

More

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

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.

Sunset Book Cover

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

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.

Gunneras

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.

More

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.

Screen Shot 2015-04-12 at 10.29.01 AM

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.

 

The Bees Need Our Help

Gardeners can enjoy gardening at many levels. We can experience the Zen of Weeding, as I did this afternoon, and then shift to enjoy one of gardening’s many other dimensions.

Gardening often turns up in the wonderful world of public policy, a dimension that can resemble a house of mirrors.

The Case of Colony Collapse Disorder, an example of gardening in public policy, is in the current news with a flurry of contradictions.

Bee on Purple Flower

Colony Collapse Disorder refers to the widespread, sudden mysterious deaths of entire bee colonies. We deplore the premature demise of these colonies, and sympathize with the industrious victims, and fear the potential threat to our own wellbeing: bees pollinate about one-third of all the fruits and vegetables we eat.

Scientists studying the causes of CCD suspect a combination of factors, and environmentalists focus on neonicontinoids, a category of very effective and widely used systemic pesticides. Both commercial crops and garden center plants and seeds are often treated with “neonics” (as they are called). Several European nations have banned neonics, but the United States currently permits their uses.

Manufacturers of neonics have insisted that CCD results from several other factors, e.g., Varroa mites, Nosema fungus, viruses, drought, and loss of habitat. Others have speculated that bee colonies are traumatized by the practice of trucking hundreds of beehives to large-scale agricultural sites, such as California’s almond trees groves.

In May of 2014, Harvard University reported an environmental scientist’s research that “strengthens the link between neonics and CCDs. The head of the National Academy of Sciences’ earlier study of the problem dismissed that research, and called it “effectively worthless,” because it was based on bees’ exposure to pesticides at doses far above typical levels.

On June 20, 2014, President Obama issued a Presidential Memorandum calling for the creation of a federal strategy to promote the health of honeybees and other pollinators. This call to action included an order for the Environmental Protection Agency to assess the effect of pesticides, including neonicotinoids, on pollinator health. The Task Force, including multiple federal departments, was to develop a National Pollinator Health Strategy within 180 days, so its report was due around Christmas time last year. Presumably, it has been subjected to internal review since that target date.

On March 20, 2015, the U.S. Department of Agriculture reported that honey production in 2014 was up 19 percent from 2013, leading some to conclude that the CCD problem was over. Beekeepers had imported Australian honeybees to replace hives lost to CCD, so that conclusion might require another look.

These events provide a glimpse of the process of creating public policies, which are influenced by environmental, economic and political forces, and which eventually impact our interests as individuals.

No one has suggested that neonics are good for the honeybees. The goal is to balance the undeniably negative effects of agricultural chemicals with the anticipated positive long-term effects on our food supplies, recreational gardening and quality of life.

Gardeners can help the bees in small ways.

  • Plant bee-friendly gardens.
  • Do not use garden chemicals containing neonics.
  • When buying plants or seeds, ask the retailer if those items are free of neonics.

Organic gardening methods would be best for gardeners…and bees!

More

A friend at Suncrest Nurseries, Inc., a large wholesale company in Watsonville, responded to this column by saying, “Suncrest does not use neonicotinoid pesticides at all, in any way, shape or form on any of it’s plants !  I think we are the only non-organic nursery to do so !”

The Internet offers much information on bees and threats to their health.  deaths. Here are some interesting websites:

UC Berkeley Urban Bee Lab

Genetic Literacy Project: The USDA Study on Bee Deaths

The Genetic Literacy Project supports GMOs, dismisses neonics’ role in bee deaths, and doesn’t like organic foods. The project seems friendly to the chemical industry.

Environmental Protection Agency to Limit Use of Neonics

USDA Release on Honey Production

An increase in honey production is welcome, but it doesn’t mean that bees and other pollinators are safe from pesticides.

Presidential Memorandum Calling for Pollinator Health Strategy

This task force was to report in 180 days. That would have been around  Christmas, 2014. Let’s watch for the report.

List of Pesticides Containing Neonics

Friends of the Earth: Bee-Toxic Pesticides in Garden Center Plants

This paper is a couple years old, but still relevant.