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 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.

Kids on Native Grass Lawn
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.

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.

 

Shrub Selection

Q. I love your column and appreciate that you invite questions.  I want to grow a thick but attractive shrub on the shady side of my house.  It receives very little sun there and is somewhat damp.  Do you have any suggestions?

I live between Fremont and Del Monte off of Montecito in Monterey, if that gives you an idea of the weather.

I like tea trees and they do well in my front yard, but there’s more sun there.  A friend recommended Dodonea, which I’m not thrilled with, but it would be okay.  I don’t know about Abutalon, it might need more sun.

If you could suggest something, I would be most grateful.

A. The Dodonaea is an interesting option, but it’s a tropical plant that appreciates more sun than you seem to have in this spot. Here’s a link to a description of the Purple-leafed Hop-Bush, from San Marcos Growers:

The Abutilon also prefers full sun. It’s attractive but may be more open in structure than you are looking for.

I prefer to recommend California native plants, as you might already know. A very good California native shrub is the Ceanothus (California Lilac), which would do well in your garden. I have a list of over twenty Ceanothus species that are shade tolerant. I could narrow down that list to a few options for your situation, based on the mature size that you would want for a plant in this location.

Let me know what height and width you have in mind for this plant.

Q. Wow!  You’re wonderful!  Thank you so much!  I agree that natives are the best, but I forget that.  Not quite there yet.  The ideal height would be around 7 feet tall.  It would be along a fence, so the width of the area I want to cover would be about 30 feet.

In my rush, I had forgotten to check what the Ceanothus looked like.  Of course, having grown up on the Peninsula, I am very familiar with it.  It’s flower is soapy, as I recall from having smashed them as a child.  This is a beautiful plant, full of color!  I love it!   With the dimensions that I gave you, do you think it would work, where would you recommend I buy it, and do you ever recommend gardeners?  Thank you!

A.

I reviewed the lists of such shrubs in a couple reference books, and searched through the inventories of some likely sources: San Marcos Growers, Suncrest Nursery, Las Pilitas Nursery and Yerba Buena Nursery. They all list several Ceanothus plants, but most are sun-loving, and the shade tolerant varieties tend to be low-growing. The remaining candidates might or might not be in stock at present.

So, on a recent visit to Native Revival Nursery, I found two varieties of Ceanothus thrysiflorus that might meet your needs. Both are listed as being shade-tolerant and capable of growing to 10 feet. When grown in partial shade, I would expect that they would not reach their maximum height, but would top out closer to the seven feet you have targeted.

These plants are in stock  at Native Revival Nursery (2600 Mar Vista Drive, Aptos).

They have both varieties in 5-gallon size for $24.99 each. The Snow Flurry is also available in 1-gallon size, for $9.99.

Blue Blossom grows to six feet wide, so for a 30-foot screen you would need five plants.

Snow Flurry grows to 8-12 feet wide (perhaps 8-9 feet wide in the partial shade), so you would need four plants.

You could mix the blossom colors, too!

Best wishes. I hope this helps.

Q. What a wonderful resource you are!  Thank you for these ideas and attachments.  I have written to the nursery and let them know that I’d like to buy three Blue Blossom and two Snow Flurry.  Thank you so much for your help!

Time to Plant Your Garden

Over the next few weeks, as we move into autumn, it is time to think about installing new plants in our gardens, and moving plants that should be in better places.

Installing or moving plants makes sense during this time of the year for two reasons. First, many plants that are good choices for Monterey Bay area gardens are entering into a dormant period, during which they can be moved with minimal trauma from one garden location to another, or from a nursery pot to a larger container or into the ground.

The second rationale for installing or moving plants now is that our familiar rainy season, beginning usually mid-October, will irrigate them during dormancy. The gentle rains of fall and winter have been a welcome gift to gardeners, who can attend to other tasks as plants develop their roots and generate new growth for the spring, as temperatures warm.

We still do not know if we will have a normal rainy season this year. Recent reports from International Research Institute for Climate and Society and the Climate Prediction Center, both trackers of the El Nino/Southern Oscillation, indicate a relatively small impact on our fall and winter weather, around 60 to 65% of the historical norm. In other words, we should expect rain, but not as much as we usually enjoy.

That forecast is more vague than gardeners would like, but now is still the time to plant. The worst-case scenario is that watering by hand or drip irrigation might be needed to keep newly installed plants adequately hydrated.

Gardeners might be inspired to bring new plants to their gardens in the spring, when garden centers are displaying plants in bloom. There are real advantages of planting in the spring: bedding plants are available in abundance, blossom colors are evident, and the weather welcomes outdoor projects. One downside of this schedule, however, is that customers pay for nurseries to care for the plants during their early growth. Also, plants that have been boosted into bloom with synthetic fertilizers often under-perform once they have been moved into typical garden soil.

When you bring new plants into your garden this autumn, choose plants that are drought tolerant and well suited for the local climate and growing conditions. Such plants are most likely to succeed under drought conditions with the only basic care by the gardener.

Remember: even drought-tolerant plants need water, just not as much and not as often.

Good opportunities soon will be available to find such suitable plants:

  • Succulent Extravaganza, September 26 & 27 (today and tomorrow); 2133 Elkhorn Road, Castroville. Info: sgplants.com, 831-632-0482.
  • Fall Plant Sale, UC Berkeley Botanical Garden, September 28; 200 Centennial Drive, Berkeley. Info: botanicalgarden.berkeley.edu, 510-643-2755.
  • Fall Plant Sale, UC Santa Cruz Arboretum & California Native Plant Society, October 11; High Street at Western Drive, Santa Cruz. Info: arboretum.ucsc.edu.
  • Fall Show & Sale, Monterey Bay Area Cactus & Succulent Society, October 18 & 19, 10 San Jose Street, San Juan Batista. Info: www.facebook.com/MonteryBayAreaCactusAndSucculentSociety

Gardening success depends on the selection of plants that are appropriate for specific locations and growing conditions. You might change where you garden, but external forces could change your garden’s growing conditions. Plan ahead!

Gardening to Save the Planet

We are learning about humanity’s many impacts on the near and distant future of our planet. Some people are in denial about these impacts, while others are concerned and ready to do whatever we can to ensure that our Earth will support future generations.

To support and encourage such positive action, leading botanist Peter Raven will visit the UCSC Arboretum next week to meet with UCSC faculty and staff, and present a public talk, “Saving Plants, Saving Ourselves.” Raven will present an informed update on the increasing threats to Earth’s environment, and emphasize the special role of public gardens in conserving plants that could be lost through habitat loss and climate change.

Peter Raven has a long friendship with the UCSC Arboretum, and a national reputation as a conservationist and advocate of global biodiversity: Time magazine hailed him as a Hero of the Planet. His visit to the Monterey Bay area inspires us to reflect on the home gardener’s unique role in saving the planet.

Here are ten everyday practices that gardeners can apply to help sustain the environment and protect plant diversity.

  • Irrigate your garden wisely, using drip technology to deliver water only where needed, and mulch (organic or inorganic) to minimize evaporation and weed growth.
  • Recycle household water into the garden, using plant-friendly soaps and detergents.
  • Prune your acquisitions of consumer goods that bury our landfills and clutter our environment…and that you really don’t need.
  • Propagate plants that Nature’s pollinators (bees and other insects, bats and birds) love and need to survive. Clusters of flowering plants will enrich your landscape.
  • Conserve biodiversity by protecting endangered species and including rare and threatened California native plants in your landscape. (Visit the California Native Plant Society’s website, www.rareplants.cnps.org/ for info.)
  • Nourish your plants with organic fertilizers, and discontinue uses of artificial chemicals
  • Control plant-eating insects with insect predators and organic insecticides. Use physical barriers and non-toxic deterrents to control other plant-eaters, e.g., snails, gophers and deer,
  • Select plants that are native to California or other summer-dry climates, to enable their healthy growth, support wildlife and ease your gardening workload.
  • Compost the “carbon-rich” fantasies of climate change deniers with the “nitrogen-rich” facts of the world’s scientists to promote wise stewardship of the environment. (Alto, keep all biomass on the property by composting green garden waste!)
  • Cultivate these good practices among your friends and neighbors.

The UCSC Arboretum employs these practices regularly, and assigns high priority to its work in plant conservation.

pt sur Austin and Tim

Click to Enlarge

This photo shows UCSC student Austin Robey and Arboretum volunteer Tim Forsell as they replanted endangered California native manzanita shrubs on a steep slope near the Point Sur State Historic Park and Lighthouse. The Arboretum’s Brett Hall coordinated the conservation project.

Your practices in your own garden also could help to save the planet. A good start would be to attend Peter Raven’s talk..

***

Registrations for the Peter Raven talk sold out quickly. To receive timely announcements of future events at the Arboretum, visit arboretum.ucsc.edu/get-involved/.

If you would like to sponsor an educational event at the UC Santa Cruz Arboretum, contact Jennifer Macotto, 831-427-2998 or jmacotto@ucsc.edu.

For information on how you could help save a rare species: visit arboretum.ucsc.edu/education/plant-sponsorship/.

Low-Maintenance Garden Themes

Designing a garden bed around a theme yields practical and aesthetic benefits.

The aesthetic benefit of thematic garden design rests on the relationships among the plants: they are linked by being members of the class defined by the theme. In that respect, a thematic group is more coherent, aesthetically, than the ever-popular “grab-bag” approach to plant selection.

The practical benefit is a plan for selecting plants from the hundreds of thousands of available varieties. Once the gardener has chosen a theme, he or she has reduced the universe of possible plants to consider. This one action narrows the selection task and supports close evaluation of options.

A garden design theme is simply a concept to which plants relate. This definition embraces a very wide range of possible themes, which could be a single color or combination of blossom colors; a plant genus, e.g., rose, iris, daffodil; size, e.g., miniatures; bee-friendly, etc.

For today’s topic, consider a progression of four themes for low-maintenance gardening.

Theme #1: Zone-appropriate Plants. Every gardener should know the U.S. Department of Agriculture’s Plant Hardiness Zone in which his or her garden exists. The Monterey Bay area is in USDA Zone 9b, where minimum temperatures are in the 25–30 degree range; plants marked for Zone 9 should survive cold spells in that range. A great many plants are that hardy, so this theme excludes only plants that are vulnerable to cold and therefore high-maintenance. Nurseries also use UCDA zones to indicate the preferred zone for given plants. Plants that are rated for Zones 10 or 11 usually will thrive best in very warm climates, not in Zone 9.

Theme #2: Mediterranean Climate Plants. These are plants that have evolved to grow well in the world’s areas that have dry summers and moderate winters. These areas (again) are native to the central coast of California, the central coast of Chile, the southwestern coast of Australia, South Africa and the Mediterranean basin. A large number of plants are suitable for this theme, but this category still is significantly smaller that Theme #1.

Theme #3: California Native Plants. This theme is within Theme #2, of course, but it stands apart from the others because includes plants that are both suitable for the Mediterranean climate and the soils and fauna of this state. Soil chemistry and symbiotic relationships with birds, mammals, insects and microbial life contribute significantly to the growth of plants, and, ultimately, the success of the gardener.

Theme #4: Native Plant Communities. A great variety of plants are native to California, and many have evolved to grow best in specific environments within the state, and in communities with specific other plants. An oak woodland plant community is certainly different from one that occurs naturally on coastal bluffs and cliffs. For the ultimate in low-maintenance gardening, adopt a thematic design for a California native plant community that would be appropriate for your garden setting.

Consider a thematic design for each garden bed or each large area of your garden. Plant selection will transform a random process to a purposeful activity.

Books for Thematic Designs

Zone-appropriate Plants
The New Western Garden Book (Sunset, 2012)

Mediterranean Plants
Plant Life in the World’s Mediterranean Climates (Dalman & Ornduff, 1998)

California Native Plants
California Native Plants for the Garden (Bornstein, Fross & O’Brien, 2005)

Native Plant Communities
Designing California Native Gardens: The Plant Community Approach to Artful, Ecological Gardens (Keator, Middlebrook & Faber, 2007)

 

Spring is Here

This year’s puzzling weather has produced a few days cold enough to promote dormancy in plants that don’t need a real winter chill, and nowhere near enough rain. We still hope late rains will replenish aquifers and reservoirs, but there’s little promise in the forecasts.

The arrival of spring does not cause abrupt change in our gardens, but it does bring warm weather that takes plants out of dormancy and stimulates new growth. Plants need moisture at this time but water restrictions demand reduction of our water usage. The middle ground for gardeners involves watering plants efficiently and only when they show need by wilting a little. This means drip irrigation if you have it, or moving a hose or watering can from plant to plant. Store your wasteful wide-area sprinkler!

If you have been preparing for drought conditions, you have emphasized summer–dry plants, a category that includes California native plants and other Mediterranean climate plants.

This is not the best year to add summer-dry plants, however: newly installed herbaceous or woody plants need regular watering for two years to establish roots.

A more appropriate strategic response to this drought is to add succulent plants, which have developed ways to minimize transpiration and maximize water retention in their leaves, stems or roots.

When added to a garden or moved within a garden, succulent plants come with their own supply of moisture, and need only minimal watering to settle their roots. They are quite resilient, but of course will need some water in time.

Succulents are far from compromises from an aesthetic perspective: they offer a range of blossom colors and foliage textures as well as low maintenance and drought tolerance. They have in fact become desirable specimens in garden beds or containers, even before our current weather concerns.

Happily, a major sale of succulent plants is less than one month away. The Monterey Bay Area Cactus and Succulent Society will hold its annual, free-admission Spring Show & Sale from 9:00 to 5:00 on April 19th and 20th in the San Juan Batista Community Hall, 10 San Jose Street, not far from the Old San Juan Batista Mission.

Screen Shot 2014-03-21 at 11.16.42 PM

The Society’s show will include members’ selected cacti and succulents, demonstrating plants that are very well grown and shown, and that display an amazing range of shapes, sizes and colors. The sale includes a great selection of mostly small plants grown by members or commercial growers, with reasonable prices. Society members also will be available to offer advice and answer questions.

Respond to this drought creatively: use this occasion to start or expand your collection of succulent plants.

More

If you are a beginning gardener of succulent plants, a helpful book is Debra Lee Baldwin’s newest book, Succulents Simplified. Her earlier books, Designing with Succulents and Succulent Container Gardens, are a more advanced, but still accessible for casual gardeners.

succulent books

Visit Debra Lee Baldwin’s website for inspiring photos and practical information.

California Native Roses

Rosa Californica is the only rose in my garden that is native to California. It’s a fine plant, but tends to expand its territory through underground suckers.

When I came upon a healthy specimen of another rose identified as a California native, I grabbed it for my garden and worked to learn more about it and other California native roses.

I soon discovered that my new rose, R. multiflora, is an imposter! It is a native to Japan that has become naturalized in California and much of the U.S. In eastern North America, it is considered an invasive species, and even a “noxious weed” in grazing areas. Although it has many blossoms, it is most appreciated by goats.

Roses that are truly native to California typically have single pink flowers, varying degrees of fragrance, and spiny branches. They often are found near water sources. While they tolerate some drought and shade they grow best with ample moisture and sunlight. They can spread vigorously in hospitable circumstances, but are controllable with seasonal pruning.

Here are several species, in roughly north-to-south order.

  • California Rose (R. Californica). Grows in much of California in chaparral, riparian and central oak woodland plant communities. Most widely grown native rose. This photo  is from the website of the University of California, Santa Cruz Natural Reserves.
    Rosa_californica_California_Wild_RoseAs a side note, the UCSC Natural Reserves program includes five sites, including one in Marina and one in Big Creek (south of Carmel). The five sites ring the Monterey Bay along the National Marine Sanctuary that extends the entire coastline from the Golden Gate at San Francisco south to Big Sur, between 38 and 36 degrees North latitude along roughly 122 degrees West longitude.The wide range of habitats, from fog-enshrouded redwood forest to maritime chaparral, provide an unparalleled natural laboratory for marine and terrestrial research and serve as study sites for University scientists and students.
  • Ground Rose (R. spithamea). Native to central California from the San Luis Obispo area up into Mendocino and Humbolt and in the Sierras from Tulare to Yuba. Grows in chaparral and coastal sage scrub plant communities.
  • Nootka Rose (R. nutkana). Grows in riparian areas in northern California and up to Alaska.
  • Wood Rose (R. gymnocarpa). Grows from San Luis Obispo to northern California, and in other western states, and has large fragrant blossoms.
  • Whiskey Rose (R. pinetorum). A relatively rare rose that has been spotted in northern California and in the Monterey area. Resembles R. gymnocarpa.
  • Cluster Rose (R. pisocarpa). A fairly large plant, up to six feet high, with flowers in clusters near the top. Grows in northern California to British Columbia.
  • Mountain Rose (R. woodsii ultramontane). Grows in high elevations east of the Sierras, and produces large numbers of very fragrant dark pink blossoms.
  • Mojave Rose (R. woodsii glabrata). Grows near springs in the Mojave Desert. Similar to R. Californica.
  • Baja Rose (R. minutifolia). Grows in Baja and the southern section of San Diego. It has very small leaves and bright pink flowers with prominent yellow stamens.

The information in this column was drawn largely from Wikipedia and the website of Las Pilates Nursery, a great source of information about California native plants.

More

This photo is from Suisun Marsh page of the California Department of Water Resources website. The photo shows Rosa Californica’s rampant growth and numerous rose hips. This plant can be controlled in a garden, through seasonal (and diligent) pruning.

0CCARosehips copy