Landscape Uses of Plant Containers

Plant containers are popular as decorative elements in the garden. A well-placed large pot can provide a focal point, and a strategically arranged series of pots can lead the eye throughout a planned tour through the garden.

The color of a container can also contribute to the aesthetic of landscape by complementing plants in or near the container or by creating a visual exclamation point in a primarily green environment. Many containers in the garden marketplace are neutral in color, but bright hues are readily available as well, and color patterns have been appearing in recent years.

Containers provide familiar artistic forms in the garden, and can also support plant growth. Empty containers can stand alone as artworks, as well. Containers of all sizes can function like sculptures at more affordable prices.

Gardeners also experiment with other low-cost alternatives to sculptures: bowling balls, wine bottle trees, farm equipment, and porcelain accessories of the home have been striking and even unforgettable sights in some gardens.

A novel use of plant containers could be as elements of a thematic landscape.

In these columns, I have from time to time advocated a thematic approach to garden design. Many possible themes could provide an identity for some or all of a garden, and thereby support a rationale for plant selection.

Garden themes oriented to a single plant genus, e.g., roses, irises, dahlias, are quite familiar. Other themes emphasize a color combination, or one color, like the historic white garden of England’s Sissinghurst Castle.

My garden has several thematic beds. The largest beds are dedicated to each of the world’s five summer-dry climates: the Mediterranean basin, South Africa, southwestern coast of Australia, the central coast of Chile, and coastal California.

These beds might need to be identified for visitors, because most will not immediately recognize the origins of plants. I have considered placing an identifying sign in each bed, but would rather avoid that institutional look.

Another method for identifying a geographically defined bed might be to place in the bed a large container from that part of the world. Assuming that the visitor will recognize the container’s country of origin, it might serve to identify the bed.

To date, that idea has succeeded in exactly one instance. A Talavera pot now marks a bed of succulent plants from Mexico, which is not one of the world’s summer-dry climates.

The accompanying photo shows this pot with a young specimen of Agave applanata ‘Cream Spike’, from Mexico.

Cream Spike Agave

Many garden centers have at least a few Talavera pots. Authentic Talavera pottery comes only from the very old city of Puebla, in southeastern Mexico, but many products come from other sources. Regardless of authenticity, Talavera pottery is strongly associated with Mexico.

A fairly good marker for the bed of plants from the Mediterranean basin is a terra cotta container that suggests a Mediterranean style, confirmed by an image search of the Internet. The casual visitor, however, might find its message to be ambiguous.

Garden centers offer a good variety of plant containers, but few refer clearly to a country of origin. For example, the city of Pomaire, south of Santiago, is famous for its pottery, but when taken out of context, the pots do not identify as Chilean.

My search for thematic plant containers has yielded information about the world’s pottery traditions, and concluded that there is no good substitute for a sign. My next step is to try hanging clay nameplates on the pots. I’ll report on that approach in a future column.

Gardening can lead us in unexpected directions!

A Not-to-Miss Event

As we enjoy the final days of winter, warmly, we begin thoughts of the arrival of spring and the reemergence of our gardens. With exquisite timing, the annual San Francisco Flower & Garden Show brings the season into focus and offers an unparalleled array of inspiration, information and products to help avid gardeners to launch the year’s gardening activities.

The SF Show began over thirty years ago as a fundraiser for the San Francisco Friends of Recreation and Parks, and soon evolved into a commercial event that features landscape designers, speakers on numerous topics in gardening, and exhibitors of plants and a wide range of garden products.

The Show ranks as one of the nation’s three largest annual events devoted to gardening and landscaping. The others are the Northwest Flower & Garden Show, which was held in mid-February in Seattle, and the Philadelphia Flower Show, which will be held March 5–13. Since 1829, the Philadelphia Horticultural Society has sponsored the Philadelphia Show as a fundraiser.

The world’s most significant competitor to these three garden shows is the Royal Horticultural Society’s Chelsea Flower Show, to be held May 24–28, 2016, at the Royal Botanical Gardens, Kew (near London).

This brief survey of major garden shows indicates that the SF Show amounts to a major event for gardeners of the west coast, and a great and accessible resource for gardeners of the Monterey Bay area.

This year’s SF Show will include 125 free seminars by gardening experts who have been selected as effective speakers. The seminar speakers and schedule is available on the SF Show’s website. The seminars are scheduled in five different stages within the San Mateo Event Center, so your attendance requires a little planning.

The Show also includes over 200 exhibitors in the Plant Market and The Marketplace. If you need any new plants or tools or garden art, you are likely to find them at the SF Show. One of the favorite exhibits is the large display by Succulent Gardens, from near Moss Landing. Early word is that this booth will be larger than ever, in response to enthusiastic collectors of succulent plants.

I will bring a couple mail order catalogs of garden plants and supplies for reference in evaluating prices at the SF Show. The prices are reasonable, I believe, but I always appreciate bargains.

The highlight for many visitors will be the Showcase Gardens, which will include nine full-size garden displays of the talents of landscape designers and craftsmen from northern California. The gardens often dazzle visitors by providing elaborate presentations of beautiful plants, stunning settings and unique concepts. These gardens present thematic designs that incorporate many ideas that can be adapted for your own garden. The designers of course will welcome new clients, and most will also be on hand to answers visitors’ question.

A day at the SF Show is really close by, not expensive, and an exceptional opportunity to bring gardening ideas and riches back home. It should be on your calendar.

If You Go

What: San Francisco Flower & Garden Show

When: March 16–20, 2016

Where: San Mateo Event Center

Info: http://sfgardenshow.com/

Drama for the Landscape

 

One of the most spectacular plants from South Africa, in exuberant bloom at this time of the year, is Aloe arborescens. It can be seen throughout the Monterey Bay area, occasionally having spread into impressively large clusters of plants.

The specific name means “tree-like,” because the plant can grow to close to ten feet high. Structurally, the plant consists of several branches, each of which ends in a rosette of leaves edged with small spikes. Each rosette can generate several flower stalks that produce cylindrical inflorescences (racemes). The individual flowers, typically a bright orange-red, are tubular and attractive to hummingbirds. The clusters of flowers resemble the flame of a torch, leading to the plant’s common name: Torch Aloe.

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Several years ago, I planted my first specimen of this succulent plant, a single rosette, in a well-drained bed. It grew rapidly and extended runners (stolons) that produced new plants, ready to take over the bed. Not knowing its full growth potential, but realizing that it was too productive for that small bed, I shovel-pruned it, replanted three rosettes in front of a nearby compost bin, and placed most of the rest in the bin.

The replanted rosettes grew readily into a dramatic presence in my garden, and also shielded the compost bin from view.

A. arborescens is related to A. vera, a smaller, more familiar South African native that is popular for its ornamental, cosmetic and medicinal values: its juices reportedly have rejuvenating, healing, or soothing properties.

The Torch Aloe also reportedly has value in promoting good health. Some people advocate a drink made from the pureed whole raw A. arborescens leaf, unheated raw honey and 1% certified organic alcohol. This drink is claimed to support immunity from a range of diseases and provide general cleansing for the whole body. It is reported to be “bitter, but unctuous and savoury as well, thanks to the honey.”

I have plenty of leaves but have not tried the drink. This is not a testimonial.

A. arborescens is one of about 500 species of the genus Aloe, which includes natives of South Africa, tropical Africa, Madagascar, Jordan, the Arabian Peninsula and some islands in the Indian Ocean. Many grow well in the summer-dry climate of the Monterey Bay area. Most species, unlike A. arborescens, are stemless: the rosettes grow directly on the ground.

A smaller, yellow-flowered variant, called Golden Torch Aloe (A. arborescens lutea), can be found in limited numbers.

Another yellow-flowered form, Yellow Aloe, was discovered in a private garden in Santa Barbara. This plant might be a variant of A. arborescens, a hybrid with another species, or an entirely different species: A. mutabilis, which has red flower buds that mature into yellow.

Aloe arborescens can be an attractive and interesting addition to a landscape that has sufficient space.

Pollinator Friendly Gardening

The current period of warm weather surely doesn’t signal the end of El Niño rains, but it does bring to mind the coming of spring. And with that cyclical change comes the inspiration to plan for garden development.

Our gardens can support many different objectives. One timely objective to consider is to support healthy lives for nature’s pollinators, primarily bees and butterflies.

We have frequently touched upon the vital role that bees and butterflies fill in the propagation of plants. The development of fruits and vegetables, which are essentially seed cases, often depends on bees, and butterflies are important pollinators of wild and cultivated flowers.

Our pollinators are threatened by civilization, notably habitat loss and agricultural chemicals. In May of 2015, the U.S. Dept. of Agriculture and the Environmental Protection Agency, in response to a directive by President Obama, established the Pollinator Health Task Force. That multi-agency group has begun reporting on studies and releasing recommendations to help bees and butterflies. We can expect a continuing flow of constructive new directions.

In June of 2015, with endorsement by First Lady Michelle Obama, environmentalists created the National Pollinator Garden Network and launched the Million Pollinator Challenge, with the goal to create one million new pollinator gardens by the end of 2016. Clearly, individual gardeners are invited to join in nationwide efforts to support pollinators.

In this context, we have a new book by Master Gardener Rhonda Fleming Hayes: Pollinator Friendly Gardening, (Voyageur Press, 2015).

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This is a valuable resource for developing a garden that supports healthy lives for bees and butterflies. Fleming, a dedicated advocate of pollinators, provides a readable and complete introduction to the subject and maintains a calm and informative style. (We respect fervent commitment to a cause, but the strident alarms and urgent calls to action we sometimes see can be trying.)

Fleming offers three principals for pollinator-friendly gardening: provide blooming plants all year, allow nesting and overwintering sites, and avoid uses of pesticides.

She also focuses on native plants, which have co-evolved with many insects and developed reciprocal dependencies. These relationships are site-specific so that the plants and insects that are native to California are not the same as the plants and insects of the east coast of the U.S. Many garden books, including this one, address national readerships, so each reader should adapt plant lists to his or her own garden environment.

Also, note that honeybees were imported to the U.S. long ago from Europe and other regions, and do not relate to U.S. native plants in the same way as the thousands of species of U.S. native bees. Imported bees particularly appreciate plants from their native lands that have been introduced in the U.S.

Here are sources for more information on pollinator-friendly gardening:

The Pollinator Partnership

National Pollinator Garden Network

Xerces Society

Monarch Watch

Ladybird Johnson Wildflower Center

A pollinator-friendly garden has direct benefits for the bees and butterflies, and also serves the gardener with the pleasure of beautiful surroundings and the satisfaction of ecologically sound practices. Also, an enjoyable and educational counterpart to bird-watching is the emerging activity of bee-watching. There is much to learn from the bees!

Adding Unexpected Plants to Your Garden

This column presents a case study of adding an unexpected and unfamiliar plant to one’s garden.

A friend gave me a plant that had outgrown its container, and no longer had a place in its previous home. My friend didn’t have a name for the plant, but a neighbor’s garden has a related species: the photo shows much longer leaves than my gift plant, and the potential to grow rather large.

Dyckia

I had never grown a plant like this one, so I was immediately interested. Here is a suggested intake process.

First, inspect the plant visually to check that it is healthy and free of disease or pests. This plant had some dieback from normal aging and outgrowing a large container, but otherwise looked healthy. I gladly accepted the gift.

Identification should be the next priority. I had seen this plant in four-inch pots, and knew it as a Dyckia, but learning the genus and species of a new plant can be challenging. This plant doesn’t appear in Sunset’s Western Garden Book, a convenient reference. In such cases, asking other gardeners or garden center staff can be the best strategy.

Then, examine the plant’s size and characteristics. This Dyckia develops several rosettes eight-to-twelve inches in diameter. Each rosette is comprised of many thin leaves up to eight inches long, with very sharp terminal spines and numerous sharp teeth on both sides. (My neighbor’s magnificent Dyckia has leaves up to two feet long!) The plant is attractive, but neither welcoming nor easily handled!

Considering both this plant’s mature size and hazards, I concluded that it should be should be three feet from any walkway, but still close enough to appreciate its intricate leaf structure.

Also, it should not be under a tree, as it would be difficult to groom dropped leaves from the Dykia’s spiny cluster.

Then, learning about the plant’s cultivation needs will guide planting and future care. An Internet search for “Dyckia” brought me these websites: Wikipedia; Bromeliad Society of Houston; Yucco Do Nursery; Annie’s Magic Garden; and Dyckia Brazil.

Dyckias, I learned, are native to Brazil, members of the Bromeliad family, and related to pineapples (Ananas comosus), Puyas, Tellandsias, and Bilbergias. There are some 158 species of Dyckias.

After comparing my specimen’s appearance with others on the Internet, I concluded that it is D. fosteriana, which is a popular species. This plant hybridizes easily in nature and in human hands, so many cultivars are available. Confident identification requires a specialist.

The Dyckia lacks internal water storage tissue, so it’s not a true succulent, but it will go dormant in response to a lack of moisture. It prefers full sun but will manage partial shade, and has exceptional tolerance for freezing weather. It is pest-free, although snails will nibble at tender flower shoots. Generally, the Dyckia is a sturdy and trouble-free plant.

Dyckias reportedly do not like transplanting during the winter, but I proceeded still to separate and pot up six offsets (”pups”) for gifts to others, and to put my new plant in the ground. I’ll learn how well it responds.

My garden lacks a bed for Brazilian plants. I accommodated this unusual new plant by redefining my existing Chilean bed as Chilean/South American.

Avid gardeners should welcome unexpected, unusual and attractive gifts to their gardens. A systematic process can help to place the plant well and to provide the care needed for its success. New plants are gardening adventures!

Rethinking a Planting Bed

There are a few reasons for a gardener to re-think a planting bed: inspiration for a new approach, boredom with the old approach, overgrown plants (and an invasion of weeds), or a desire to improve the aesthetics.

For one of the beds in my garden, I have the urge to edit the existing plants to satisfy to a thematic concept: Mexican Succulents.

At least ten years ago, I established this bed, which is not large (almost forty square feet) but prominently located in the garden. An edge of larger stones supports a raised planting area, which is ideal for succulent plants. Over time, I installed a variety of succulent plants.

When I look at this bed now, the mix of plants leaves me uneasy. During the intervening years, I have become interested in thematic collections of plants, with an emphasis on county of origin. From that perspective, this bed was a horticultural hodge-podge.

For some gardeners, that reaction might suggest an unhealthy obsession with order, but that’s OK. It’s my garden and I can do what I want.

This concern, which has been lurking in the background for a while, was activated recently by two events. First, at a meeting of the Monterey Bay Area Cactus & Succulent Society, I attended a presentation on Agaves, a southern California succulent. Then, a friend gave me an Agave parryi (Mescal Agave), which is also from southern California and northern Mexico.

I already knew most of the plants in this bed were Mexican or southern Californian, the featured plant being a Dasylirion wheeleri, also called a Desert Spoon.

Dasylirion wheeleri

Dasylirion wheeleri, a succulent plant from Mexico, with a large South African succulent, an Aloe arborescens, in the upper left background.

My concept of “Mexican Succulents” includes southern California, because plants don’t recognize political boundaries, and besides, historically, Mexico included what we now know as southern California.

My first step toward that objective was to inventory the existing plants, to determine which should be relocated. I identified plants from South Africa: Crassula tetragona (Miniature pine Tree), Crassula argentea (Jade Plant), and an enormous Aloe arborescens (Torch Aloe), which has been screening my compost bins.

I also found plants from the Europe and the Mediterranean basin: a self-seeding Euphorbia characias wulfenii (Mediterranean Spurge), a few unidentified plants: Sedums, Sempervivum, and Aeonium.

The task, then, is to move the South African succulents to another bed that already has that theme and to move the others to the bed for Mediterranean Basin plants. The biggest challenge will be to remove the South African Torch Aloe, which needs a larger space than is available elsewhere in the garden, and to find another screen for the compost bins. Aloes are hard to kill, so I could give away cuttings at the curb for other gardeners.

Then, I could assess the newly dedicated bed for Mexican Succulents and begin filling in the empty spaces with new plants, beginning with my one Agave parryi. I probably will avoid collecting agaves because they have sharp terminal spines, are monocarpic (they die after flowering), and produce lots of offsets (pups). There are many other Mexican succulents to explore.

A good practice is to tour your garden occasionally to consider if a bed could be improved by editing the plants, or starting over entirely. It’s best to focus on a limited area, rather than taking on the entire garden at one time. Renewing a planting bed should be a creative exercise and could lead you into a new area of gardening.

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 wikipedia.org.

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.

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

 

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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

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.