Adventuresome Gardening

Regular readers of this column know of my interest in plants from the world’s summer-dry climates, also called the Mediterranean Basin regions. Many plants from these exotic regions will thrive in the Monterey Bay area, and provide attractive and exciting alternatives to the garden center’s humdrum horticulture. Cultivating such plants is the enterprise of adventuresome gardeners and seekers of botanical thrills.

There are countless examples of such plants to be discovered among the selections of mail-order nurseries, either in published catalogs or online. To be fair, local garden centers also might have a few offbeat offerings; it’s worth asking the staff to mention any unusual plants.

One candidate for a featured position in the landscape is the Puya, which is one of about fifty-seven genera in the Bromeliad family. Just about all bromeliads are native to the tropical Americas. About half of the species are epiphytes (growing on air and rain), some are lithophytes (growing on rocks), and the rest are terrestrial (growing on earth). The most familiar of the terrestrial bromeliads is the pineapple (Ananas comosus).

Another terrestrial bromeliad is the Puya. This genus includes about 210 species, several of which are native to Chile, where they have the common name chagual.

One of the Chilean Puyas is the Blue (or Turquoise) Puya (P. berteroniana). This plant grows a flower spike about six-to-ten feet tall, and has exceptional landscape value because of its extraordinary 1.5” waxy, metallic blooms of an unearthly emerald-turquoise color, with contrasting bright orange stamens. The blooms hold blue, syrupy nectar that attracts hummingbirds, bees and other pollinators.

Puya berteronianas

The Blue Puya can be found in some public gardens. I viewed several fine specimens, and took this photo, about one year ago, in the Australian National Botanic Gardens, in Canberra.

Locally, the Blue Puya is in bloom now at the UCSC Arboretum. The blooms do not last long, so to see one of nature’s most extraordinary flowers, visit the UCSC Arboretum soon. For information and pictures, visit and click on “What’s Blooming.”

The Chilean bed in my garden includes two quite young examples of this genus: a Blue Puya (P. berteroniana) and a Silver Puya (P. coerulea). These are slow-growing plants, now years away from blossoming in my garden. While they are not yet pleasing my eyes, they are already trying my patience (a little) and piquing my imagination.

Annie’s Annuals lists nine Puya species, but current availability includes just three. Similarly, the wholesale nursery San Marcos Growers lists eight Puya species, with just three currently in production. Your local garden center could special-order plants from these nurseries, or another preferred source. Search the Internet by botanical name for information to share with garden visitors.

You certainly can keep your garden’s tried and true selections, but consider adding exotic plants to enrich your landscape.

Exotic Bulbs for Spring Bloom

As we proceed into autumn, the gardener’s thoughts turn to the gratifying display of spring bulbs.

If your garden already includes bulbs that bloom each spring, and you have all you want, relax and let nature do its thing!

If you want more blooms to brighten your spring, however, plant bulbs during the next few weeks.

The general rule is to plant bulbs before the ground freezes, but Monterey Bay area gardeners can only imagine a freeze to schedule bulb planting.

In this temperate climate, bulbs that do not require vernalization (dormant period chilling) are most convenient.

There are many bulbs in this category, including the popular narcissus, plus allium, colchicum, crinum, crocus, gloriosa lily, hyacinth, kaffir lily, muscari, snowflake, spider lily, and watsonia. Most of these are members of the large lily family (Liliaceae), which also includes the tulip.

Several species tulips require little chilling during their dormant period, including Tulipa bakeri ‘Lilac Wonder’, T. clusiana (Lady Tulip), T. saxatilis (Candia Tulip) and T. sylvestris (Florentine Tulip). All these produce demure, colorful blooms.

By contrast, hybridized tulips, with larger blooms and taller stalks, require chilling. Some helpful suppliers offer pre-chilled bulbs of hybridized tulips.

Bulbous plants are native to the globe’s five summer-dry climates, particularly the Mediterranean region, South Africa, and California. Adventuresome gardeners can have a great time growing spring bulbs from one or more of these areas.

Triteleia laxa

Triteleia laxa ‘Queen Fabiola’

Such projects require some research. The larger mail-order bulb suppliers offer at least a few bulbous species from faraway places, among the mainstream varieties, but their catalogs have inconsistent information about the country of origin.

Here are sources of bulbous plant information, by country of origin:

  • Pacific Bulb Society’s Wiki, a volunteer-written on-line encyclopedia of flowering bulbs, with photographs.
  • Telos Rare Bulbs, a mail-order nursery in Ferndale (on the California coast, near the state’s northern border), offers a great selection of native plants of California, South America and South Africa.
  • Mediterranean Area: Alpine Garden Society lists specialized books on bulbous plants, including Bulbs of the Eastern Mediterranean, by botanist Oron Peri. The bulbous plant cognoscenti are thrilled with this newly released book.
  • South Africa: The Color Encyclopedia of Cape Bulbs (2002), by John C. Manning, Peter Goldblatt, and Dee Snijman.
  • Chile: Few bulbous plants are native to Chile, including Glory-of-the-Sun (Leucocoryne) and the striking—and rare—Blue Chilean Crocus (Tecophileae cyanocrocus). Both are available from Telos Rare Bulbs. For the short list, visit Chileflora (click on Seeds Shop/Life Form: Bulbous Plants) or Sacred Succulents (click on Rare & Beneficial Plants from Chile), a small, family-run business in Sebastopol, California.
  • Australia: Gardeners of the land down under cultivate several bulbous plants that originated in other areas, but apparently few if any that are native to Australia. (If you know of any, let me know.) The region’s popular Chocolate Lily (Dichopogon strictus) is attractive, but it’s tuberous, not bulbous.

Screen Shot 2015-11-14 at 12.20.55 PMThrough a recent search of the Internet. I found a new book by Attila Kapitany, Australian Native Bulbs (2015). This book highlights eight native
species of bulbs, corms, and tubers, and “discusses many more.” It is available on eBay with shipping costs for the interested buyer to discover.





Cultivating exotic bulbs can be challenging, intriguing and rewarding, as beautiful and out-of-the-ordinary blooms appear in the spring.


Comments and Questions are Welcome


Landscaping with Succulents

As we await El Niño rains, the Monterey Bay area’s familiar rainy season is already late in starting, and we feel the pull of long-term perspectives on gardening.

Let’s consider landscaping with succulents plants, which are gaining appeal for their interesting foliage forms and colors, ease of cultivation and propagation and of course drought tolerance.

Many succulent plants can hold their own in the garden as specimens or aesthetic statements, but when we group several plants, they relate to one another in various ways and we have a landscape, either by design or by chance.

Tiered Succulent Display

Tiered Display of Succulents in Sidney, Australia

Landscaping by chance is often popular, but with a little planning, gardeners can succeed with more deliberate methods.

Designing with plants involves individual preferences and styles, which we always respect. There are, however, a few broad guidelines to consider.

The first of these is “taller plants in back,” which is about visibility. Take the time to learn the mature height of each plant. Here is information sheet from succulent expert Debra Lee Baldwin, listing popular succulent plants by height: Instant Gardens.

Another organizing guideline is to group plants by their watering needs. This technique, called hydrozoning, works with nature (always a good idea!) and makes garden maintenance easier.

Using this technique requires knowing the watering needs of the succulent plants in your landscape. All succulent plants need some water, particularly during their growth periods. They need much less during dormancy.

The two broad categories of succulent plants are the “winter dormant,” i.e., plants that grow during the spring and summer, and the “summer dormant,” i.e., those that grow mostly during the fall through early spring. Here is a link to winter dormant and summer dormant succulent plants.

The landscape designer also could group plants by county of origin. Such grouping is a step toward creating plant communities, which are combinations of plants that are found in natural settings. Such combinations reflect the plants’ common needs for soil, exposure, climate and other factors. Gardening in this way involves detailed cultivation methods. Grouping plants by country of origin is relatively easy, while respecting nature and developing an interesting landscape. The avid gardener can discover a plant’s country of origin from some books and plant labels, or by entering the plant’s botanical name in

Finally, consider combining succulent plants with grasses, which are another category of drought-tolerant plants. Grasses typically respond to severely dry conditions by going dormant, rather than by storing moisture, and grass-succulent combinations are seen in natural settings. The benefit of combining succulents and grasses is primarily in the aesthetic effect of contrasting the succulent’s fleshiness with the grass’s wispiness. To learn more about grasses, see the book, The American Meadow Garden (2009), by John Greenlee and Saxon Holt.

For more comprehensive guidance, Debra Lee Baldwin’s book, Designing with Succulents (2007), provides inspiring ideas for planning your own succulent garden area.

Preparing for long-term water shortages certainly includes defensive strategies, but your preparations can include landscaping with succulents as an absorbing and creative exercise.

Evolution of the Community Garden

I never expected to be impressed by a housing development in the San Jose area, but late in September of 2015, the City of Santa Clara launched an extraordinary project that City Council member Lisa Gilmor said is“…the first of its kind for Santa Clara. I don’t think we’ve done anything like this in the past.”

The Council selected a developer, The Core Companies, to lead master planning and development of a six-acre site on Winchester Boulevard, near the Valley Fair and Santana Row shopping centers.

Win6 Project - conceptual

Core/CNGF Project – Conceptual

The project concept combines housing with several familiar elements: a small organic farm, community gardens, a children’s garden, California native plant edible landscaping, roof gardens, solar energy production, a farmer’s market, a rainwater garden, an outdoor kitchen, and much more.

Overall, the project qualifies as an “agrihood,” a newer idea that focuses residential housing on a working farm, rather than a pool, tennis court or golf course. An agrihood also engages the residents in creating a sustainable food system for the entire community.

This concept could be appealing to people of all ages, but the United States has only a short list of existing agrihoods (for examples: The Santa Clara project appears to be the only agrihood in an intensely urban environment, and an exceptional showcase of several ideas in sustainable gardening.

The City of Santa Clara selected this project among eight competing proposals because of its creativity, vigorous community support and the history of the site, which had been part of an agricultural research station operated by the University of California, beginning in the last 1950s.

A visionary neighbor, Kirk Vartan, galvanized community support for this project. He found a creative and knowledgeable ally in Alrie Middlebrook, a landscape designer and leader of the California Native Garden Foundation, a non-profit group that demonstrates innovative gardening ideas and supports the development of school gardens. Middlebrook’s ideas are evident in the rich array of gardens in this agrihood, which has been called the Core/CNGF project.

The California Native Garden Foundation will be involved in managing the project’s urban agriculture open space. (Full disclosure: as a long-time member of the CNGF’s board of directors, I have had both opportunities to monitor this project’s development during the past several months, and a very limited role in its creation. The CNGF board’s primary role is to review schools’ applications for the planning and development of learning gardens.)

Agrihoods could become the evolutionary next step beyond community gardens and community-supported agriculture. Through this project in nearby Santa Clara, we can see the leading edge of innovative strategies for relating research-based gardening and community relationships.

Leaf Blowers

In recent columns, I have addressed soil health as an emerging issue in global climate change, and described ways in which residential gardeners could participate in solutions to this high-level priority. The most important strategies for home gardeners in this connection include using mulches and cover crops to protect the soil from the elements; avoiding uses of synthetic chemicals, which attack the soil microbiome, and favoring regionally appropriate plants, including (for the Monterey Bay area) plants that are native to California and other dry-summer climate regions.

Today’s column focuses on uses of gasoline-powered garden equipment: leaf blowers, lawnmowers, lawn edgers and chain saws.

This equipment contributes to climate change and air pollution. The typical device uses a two-stroke engine, which, by design, does not burn the fuel efficiently, and instead emits large quantities of carbon monoxide, nitrous oxides and hydrocarbons. These emissions contribute to smog formation, climate change and acid rain, and hydrocarbons in particular can be carcinogenic.

Small trucks and passenger cars also produce worrisome emissions, but gasoline-powered garden equipment emit them at much greater rates. For example, leaf blowers produce 100 to 300 times as many hydrocarbons as does a small truck or passenger vehicle. Garden equipment with four-stroke engines perform significantly better, but still far worse than car engines.

In terms of environmental pollution, these are very dirty devices.

The California Air Resources Board has stated, “Potential health effects from exhaust emissions, fugitive dust, and noise range from mild to serious.”

Fugitive dust includes organic debris and “particulate matter,” which can include a variety of potentially nasty organic and chemical stuff that people should not breathe.

Noise pollution effects include annoyance, hearing loss (particularly by equipment operators), and a range of psychological impacts.

For more information, visit the website of Zero Air Pollution ( This southern California organization details the range of health hazards associated with this garden equipment, wherever it is used.

Leaf blowers sometimes are used to clear organic materials, and leave bare soil. Making nature “tidy” in this way exposes the soil to the damaging effects of the sun and wind. The regeneration of healthy soil requires maintaining cover of vegetation or mulch materials.

Here are recommendations for ecologically appropriate uses of garden equipment.

  1. Minimize or eliminate the use of gasoline-powered devices in favor of manual equipment. Use rakes and brooms to clear leaves, a push lawnmower to cut grass, a long-handled edger to trim lawns, and a handsaw to prune limbs. These tools are consistent with a contemplative approach to gardening, and provide desirable exercise.
  2. When the task requires too much time and effort for manual equipment, use electrical devices. Battery technology is advancing to enable longer operation of small garden equipment; corded devices, although cumbersome, work quite well. (My corded leaf blower moves leaves nicely.)
  3. Negotiate with your “mow, blow & go” garden maintenance contractor to use manual equipment whenever possible. This might require a small rate increase, but everyone will be better for the effort.

Continue reading

South African Flora

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.9-11-15 Protea
  • Leucospermums (pincushions), most reach four-to-five feet tall, with yellow, orange, pink or red flowers.

9-11-15 Leucospermum

  • 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.

9-11-15 Leucadendron

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, 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.

Updating the Landscape

August might not be the best time of the year to work in your garden.

Even the Monterey Bay area’s temperate climate can be uncomfortably hot for digging (if that is among your priorities).

The early morning hours can be a fine time to keep up the chores, but using that time presumes readiness for an early start and control over the day’s schedule, which is not everyone’s situation.

Still, the lazy days of summer include opportunities for creative advances in the garden.

A priority task that is too often neglected, and could be pursued now in a timely way, is the annual assessment and adjustment of the home landscape.

The assessment process can involve a slow inspection walk through the garden, but ideally includes choosing a vantage point where a comfortable seat and a cool drink will support appraising each significant plant, and envisioning the renewal of the landscape.

Screen Shot 2015-08-15 at 11.01.27 AM

Take a little time for this important task, which can guide progress during cooler days, which are not far off, and chart longer-term improvements.

Right now is also a good time for your review of the landscape because in about two months, with optimism, we will begin our rainy season. At that time, we should have new plants in the ground, because the rains will keep them watered as they become established.

This review presents a good opportunity to recruit a fellow gardener to provide a second opinion. Invite reciprocal visits with someone who both respects the current restraints on your time and resources, and brings a creative perspective to the process.

When appraising the landscape, look for…

  • Plants that have been neglected, and consequently are struggling, dying or already dead.
  • Plants that are overgrown, and have begun intruding on walkways or crowding other plants.
  • Plants that need dividing to perform well. (Dig and replant irises this month and next.)
  • Plants that were misplaced originally, and would look better in another spot.
  • Areas that would be improved by the addition of a new plant of a particular size, blossom color or form.

The last appraisal listed above will require study to identify the right plants for addition to the garden. This could involve visits to the local garden center, or reviews of printed catalogs or websites. A neighborhood stroll is always a practical approach to finding plants that would work well in your garden and flourish your local growing conditions. When you see a desirable plant, ask the homeowner to name the plant so you could search the web for its cultivation needs.

Summarize the findings of the appraisal in a task list with target dates for needed adjustments.

Regular reviews and adjustments of your landscape will keep it looking fresh and interesting. Such reviews could be done annually, as proposed here, or at the beginning of each season.

Our gardens please us because they are alive and always changing, so gardening succeeds best when gardeners interact with Nature.

Restoring Soil

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 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.

Kids on Native Grass Lawn

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.

Rain Gardens – Advanced Water Conservation

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.

Rain Garden - Sentinel

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

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.


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.,, and click on “Images.” This will yield numerous photos of the plant, often showing considerable variation within the genus.