Gardening Close Up

 

We garden on different perspectives: specific when studying individual plants, and general when designing a landscape. We can regard gardening as a continuum with many points between its ends. This range of possible perspectives deepens our interest in gardening.

With all that in mind, where does the survey of a genus belong on this continuum? That thought came to mind during a recent talk by Brian Kemble, Curator of The Ruth Bancroft Garden in Walnut Creek, specializing in succulent plants.

Ruth Bancroft established this extraordinary garden in 1972 as her private collection. It was the first garden supported by the Garden Conservancy, and in fact inspired the formation of that nation-wide organization. The garden was opened to the public in the early 1990s and soon became managed by a non-profit corporation.

Brian Kemble 3-2015

Brian Kemble, Cactus & Succulent Horticulturist

Kemble has been involved with the garden continuously since 1980, and has brought his considerable knowledge of horticulture and his expertise in succulent plants to the cultivation and development of the garden. Ms. Bancroft, now 106 years of age, maintains her interest in the collection.

Kemble spoke to the Monterey Bay Area Cactus and Succulent Society, in Watsonville. His talk focused on the genus Gasteria, a South African member of the Aloaceae plant family, which includes other popular genera: Aloe, Bulbine, Haworthia and others.

The name of the genus Gasteria reflects its flowers, which to some observers are stomach-shaped (“gaster” is Latin for “stomach). The flowers hang from inclined long racemes, which can includes clusters of 100 or more flowers. The flowers range in color from pink to vermillion with yellow-green tips.

The genus includes 22 species, with rosettes ranging in size from the diameter of a nickel coin, to those with leaves a meter long.

Gasteria acinacifolia

This is a Scimitar-leaved Gasteria (G. acinacifolia), displayed at the meeting of the Monterey Bay Cactus & Succulent Society, as part of the monthly mini-show. (It won a prize in its category!)  This is the tallest of the Gasteria species, native to the Eastern Cape of South Africa.

Kemble showed examples of several Gasteria species, each of which is native to a specific area of South Africa. He also showed several hybrid forms, including at least one that he developed himself.

Gasterias are relatively easy to propagate from seeds, divisions or leaf sections. They are also readily crossed with other plants in the Aloaceae family, so we have cultivars called xGasteraloe or xGasterhaworthia.

Kemble provided an expert overview of this interesting genus Gasteria. Some members of his audience might have been inspired to collect different species of the genus, but others most likely learned about how any given Gasteria fits into the larger botanical context. This knowledge adds in subtle ways to the enjoyment of gardening.

To learn more about Gasterias and other succulent plants, visit the web site of the Monterey Bay Cactus & Succulent Society, and click on
Specific Resources. Gasterias, as you will recall, are in the plant family Aloaceae.

 

Bare Root Trees and Shrubs

One of the best bargains in gardening is planting bare root trees and shrubs. And now is the time to do just that.

Bare root trees are dormant, by definition, and not attractive in the usual way, but they are excellent candidates for addition to your garden.

Bare Root Tree

Click to Enlarge

I have often written of the advantages of buying mail order plants, to draw from a wider selection than local garden centers can offer. That’s still a good practice for many plants, although there are drawbacks, as well: mail order buyers need to confirm that the plant of interest is right for their garden, particularly in terms of winter temperatures. Some tropical plants will not survive even the moderate winters of the Monterey Bay area, and some require more winter chill than they will receive in our climate, and will not blossom or fruit well here.

Years ago, eager to start a small orchard of antique varieties of apple and pear trees, I ordered ten bare root plants from a mid-west nursery, only to watch them struggle and eventually fail for lack of winter chill. Purely by chance, one tree, a Cox’s Orange Pippin, managed to survive my garden’s USDA zone and is producing very tasty apples to this year. That tree stands to remind me to do my homework before ordering mail order plants.

The hazards of selection are less important during bare root season because local garden centers are able to stock very good inventories of bare root trees and shrubs that are right for the local climate.

Despite the best efforts of garden centers, the economics of stocking containerized plants limit inventories of plants in pots: they cost more to ship and require more space, and offered at twice the price of the same plant in bare root.

Conversely, mail order suppliers (which still might offer a greater range of choices) can ship wholesale orders of bare root plants efficiently to garden centers, but have to recover the greater costs of shipping small quantities of plants to retail purchasers. So, for individual gardeners, the mail order price could be higher than the garden center price.

Additional benefits of buying bare root plants include larger root mass, according to researchers, easier to move and plant without soil and container, and faster growth because they adapt easily to local soil as they come out of dormancy.

The range of options at a garden center could include ornamentals, fruit trees, roses and berries. Many other shrubs could be offered in bare root form, as well, with the same advantages, but I have seen little development of that market.

When selecting an ornamental or fruit tree, look for a straight trunk, evenly spaced branches (if any), good spread of healthy-looking roots that have been kept moist, and a complete lack of any wounds or disease.

Many garden centers also offer espaliered fruit trees that have been developed by grafting branches in the right places, rather than by the time- and labor-consuming process of training. Some espaliered dwarf apple trees include grafts of several apple varieties, to produce a healthy young tree that will both fit a tight space in the garden and produce a selection of applies that ripen at different times during the season.

It is important to plant bare root specimens before bud break, so there is a small window of opportunity for the lowest prices. Don’t delay!

Roses for Foggy Areas

Q. Are there any hardy roses you would suggest I could plant that will survive Pacific Grove’s sandy soil and fog?

I enjoy your column.

December 2013

A. In December, it’s appropriate to strip leaves from roses to encourage dormancy. Just pull them off by hand and rake up under the rose bush to minimize any disease and over-wintering pests.

Treat the sandy soil and fog as two different issues. (They are both manageable.)

Sand in the soil helps drainage (which roses and most other plants appreciate), but there can be too much of a good thing. The sand content of your soil should be between 10% and 30%. I recommend analyzing soil texture so that you will know what you have. Here is a link to Fine Gardening magazine article, “How is Your Soil Texture?” that describes a simple procedures that you can do in a few minutes and without cost.

If this test shows an excess of sand, add compost or other organic material to improve the mix. During January or February, you could lift the rose, dig a hole about twice the size of the root ball, fill the hole with a mixture of garden soil, sand and compost, replant the rose, and water in. There is no correct mixture, but you might try for something like 70% soil, 20% sand and 10% organic material.

When lifting the rose, first use a shovel to cut the roots to about six inches around the plant. You could lift the plant without soil around the roots, but keep the roots moist (or at least out of the sun) until replanting.

A foggy environment has good and bad effects. Fog will help to keep the rose from drying out, but it will also promote various diseases, e.g., mildew, black spot, rust. The best strategy lis to select disease-resistant roses. Here’s a link to a Sunset magazine article, “Roses for Foggy Coasts,” with a list of rose recommendations.

The article recommends seeking advice from members of the local rose society. The Monterey Bay Rose Society has several members who are qualified Consulting Rosarians, and generous with their expertise.

Lose the Lawn

One the best gardening strategies to prepare for future droughts—and achieve additional benefits—is to replace your lawn with any of several landscape designs.

Lawns, and especially front yard lawns, began as a mark of affluence, because mowing a lawn was once a labor-intensive (and therefore costly) session with a scythe. A skilled scythe-wielding worker can be impressively efficient, but for most workers, including the homeowner with an up-to-date lawnmower, mowing a lawn is a tedious and repetitious task. The homeowner’s reward for a well-maintained lawn can include pride of ownership.

A lawn does more than display the homeowner’s wealth. It also serves as the base for widely accepted front-yard designs, the principal one of which has been called the Contractor’s Landscape. This consists of a shallow bed of reliable small shrubs next to the house, followed by turf grass to the curb. This design is quick and cheap to install, and inoffensive.

From an aesthetic viewpoint, the lawn provides a resting place for the eye as the viewer focuses on individual trees, shrubs and blossoms. The lawn is a neutral swatch of greenery, contrasting carpet-like with the relatively busy landscape.

But consider the negative aspects of the lawn.

  • Maintaining a good-looking lawn requires much more effort, water, chemical fertilizers and herbicides than alternative landscapes.
  • Two-cycle lawnmowers pollute the air about ten times as much as a car, and add noise pollution as well. Electric mowers are better, but they also impact the environment. Push mowers are best for the environment, the lawn and the homeowner.
  • Lawns are the homeowner’s version of monoculture, growing just one crop over an area. This practice might seem efficient, but to the wildlife, it’s a wasteland with very little food or water and no shelter at all.
  • Lawns might be valued for recreation, but in reality often have minimal use (except for maintenance). Other landscape designs could be more inviting and supportive of outdoor activities.

If these factors encourage you to consider losing your lawn, it’s time to look into the many possible alternatives. Begin with Sunset magazine’s “21 Inspiring Lawn-free Yards” <www.sunset.com/garden/earth-friendly/lose-the-lawn-low-water-landscaping>. This webpage offers a slideshow of attractive options to contemplate.

For more in-depth information, visit Evelyn J. Hadden’s extensive website, “Less Lawn, More Life,” or look for her book, “Beautiful No-Mow Lawns: 50 Amazing Lawn Alternatives’ (Timber Press, 2012).

Another fine resource on this topic is book by Carol Bornstein, David Fross and Bart O’Brien: Reimagining the California Lawn: Water-conserving Plants, Practices andDesigns (

Another helpful resource is the Lawn Reform Coalition, which is “all about reducing or replacing lawn, water-wise lawn species and eco-friendly care for all lawns.” Visit the Coalition’s website for information on all aspects of lawn alternatives.

“Lose the lawn” emphasizes the loss of a familiar element of the landscape. “Lawn alternatives” suggests a more appealing idea, one that opens our thinking about creative approaches to the landscape and new resources in the home environment.

Think of the possibilities!

Rain at Last

As an impressionistic meteorologist, I’m very pleased with our recent rains and even more so with the promise of more rain in the near future. Some areas of northern and central California could actually reach normal levels of annual precipitation. The Santa Cruz area is during fairly well, but this happy future might not extend throughout the area: portions of Monterey County are receiving lighter precipitation.

What have we learned?

My first reaction to the overdue rain is that we can now anticipate fresh new stems and leaves and a great floral display in the spring. Our plants are responding to the moisture by extending their roots and drawing in nutrients, preparing for a new season of growth.

Then, I flashed on the idea that the drought is over for good, and we’re back to the Monterey Bay area’s historical weather pattern, with a dry summer and the onset of the rainy season around mid-October. This thought didn’t last long. Realistically, our climate is changing in ways that will change our gardening—and our lives—in significant ways.

This change is happening at a fast rate, not with the very slow arrival of the Ice Age (approximately 110,000 to 12,000 years ago or the Little Ice Age (1550 to 1850), which developed relatively more quickly, over a period of about 200 years.

Politicians are debating a range of responses to today’s emerging problem. Clearly this is a global issue that requires global action, but as individuals, we can respond in small ways. The most constructive action for individuals is to elect those who accept the reality of climate change and support long-term solutions.

As gardeners, we can pursue three basic strategies:

First, retire plants that require summer irrigation and that suffer under drought conditions. The single most widespread plant in this category is lawn grass, which achieves it aesthetic potential only with frequent irrigation, applications of nitrogen fertilizers and broadleaf herbicides, and regular cultivation, including mowing, aeration and pest control.

In a future column, I will describe alternatives to traditional turf grasses.

Tropical-climate plants compirse another category to avoid for drought-tolerant gardens. Examples include the hibiscus (H. syriacus is the most popular ornamental species) and the banana (Musa acuminata, M. balbisiana and others). In general, avoid plants with large glossy dark leaves, which tend to absorb more heat, require a lot of water and transpire a lot of water.

For the water needs of specific plants, Sunset’s Western Garden Book provides useful guidelines, with briefly descriptive terms from “ample water” to “little to moderate water.”

The second basic strategy is to favor plants that will survive in your garden under drought conditions. Generally, as often mentioned in the column, these are plants that are native to coastal California and other Mediterranean (or “summer-dry”) climates. These plants will do better with a little moisture during a prolonged drought, but they have evolved to withstand dry periods, using such methods as growing small leaves, that minimize water loss.

Succulents are another category of drought-tolerant plants, which have developed structures for storing water in their leaves, stems or roots.

The third strategy for drought-tolerant gardening is to use water wisely, through drip irrigation and regular mulching. These water-conservation methods complement the two preceding strategies for plant selection, and help the gardener to cope with water restrictions.

Use the next clear days to assess your garden for drought-tolerance. However much we enjoy the current rains, preparing for future droughts requires long-term planning..

Summer Pruning of Apple Trees

Do you have one or more apple trees that have vigorous new upright growth, like the shoots, often called water sprouts, shown in the picture? This photo shows new growth on an espaliered Gala apple in my garden, before and after pruning (click to enlarge).

BEFORE PRUNING

Water Sprouts - vert

AFTER PRUNINGWater Sprouts - pruned

Those shoots, usually at least one foot in length, are the tree’s response to heavy pruning during the dormant season, and represent an effort to restore the balance between the canopy and the root system.

Water sprouts are unlikely ever to bear fruit. Instead, they sap the tree’s energy and shade the interior of the tree, slowing the development of vertical growth, and the time for dealing that problem begins now. The period from early August to mid-September is the ideal time for summer pruning, after the new branches have set their terminal buds. This means that the branch has stopped growing for the season, so pruning will not stimulate additional growth. The best practice is to remove the water sprouts with their terminal buds.

Note that some new shoots will be shorter, and horizontal or nearly horizontal. Horizontal shoots (properly called “laterals”) are more likely eventually to bear fruit, so they are treated differently from the vertical or near-vertical shoots.

First, consider training these laterals to close to horizontal, using string or V=notched spreaders, to support fruiting.

Then the recommended treatment is to prune these laterals back to three buds of new growth after the cluster of leaves at its base. This will stimulate the formation of fruiting buds.

Oren Martin, the gardening guru at UC Santa Cruz’s Farm & Garden, says this three-bud pruning system is based on the advice of Louise Lorette a French orchardist of the early 20th century.

Pruning your apple tree’s water sprouts and laterals in this manner can be a repetitious and fussy detailed task, but it really will not take long and will contribute significantly to your tree’s vigor and productivity.

My practice is to listen to National Public Radio on a portable radio while pursuing repetitious tasks like pruning or weeding. That way I can feel like both a conscientious gardener and an informed citizen.

Summer pruning of apple trees is distinctly different from winter pruning, which should focus on the tree’s structure and overall form. Summer pruning, by contrast, emphasizes the tree’s details, keeps sunlight flowing to the interior and supports fruit production

The time for structural pruning of an apple tree is late winter while the tree is dormant and leafless. Winter pruning can stimulate the growth of water sprouts, which are pruned in summer when the tree is not producing new growth. This practice results in less pruning down the line.

When the dormant season comes again, we’ll review the art of winter pruning. Now, during the summer months, pick up your clippers and snip away at those water sprouts.

Gardens as Tools

Following recent surgery, I felt too fatigued and sore for even light gardening. Those limitations lasted about one week, after which I could again put in several hours on easy—and overdue— tasks: weeding, installing small plants, pruning, all of which helped a lot in my recovery.

This episode stimulated thoughts of the garden’s many functions beyond pleasing the eye, feeding the stomach and providing regular light exercise.

Without minimizing the direct benefits of ornamental and edible gardening, consider the types of therapeutic gardens: healing, meditation, contemplation, and restorative.

“Healing” means helping individuals to overcome physical, mental, emotional or spiritual challenges.

“Meditation” involves deepening personal knowledge and attaining inner peace.

“Contemplation” involves thoughtfully examining issues larger than oneself, perhaps in a religious or mystical manner.

“Restoration” refers to returning to an ideal or normal state from a stressed or agitated state, or from boredom or difficulty in focusing.

A garden designed to help individuals to overcome physical challenges is described as an accessible garden. The design typically emphasizes raised beds, tall enough to provide easy access to the gardener who cannot kneel, or finds it difficult to do so. (Rising from kneeling could be just as challenging.) There are also convenient tools, e.g., rolling seats, tools with long handles, telescoping pruners, for gardeners who have grown to be less than spry.

Other kinds of accessible gardens are designed for gardeners with partial or complete loss of sight, emphasizing blossom fragrance or plant texture over appearance, to favor smell or touch.

No garden, however accessible or well intentioned actually effects any healing or restoration. Only the gardener who desires to be healed or restored can achieve such outcomes. In this perspective, the garden is not the cure, only the gardener’s tool.

The focus on the gardener is the same for meditation and contemplation gardens, which offer only nature’s calm environment to invite the gardener to forget for the moment personal stresses and the busy world’s demands, and to consider issues greater than “why snails?”

There’s one more type of therapeutic garden: the motivational garden, which helps those who may be bored or having difficulty in focusing.  Once we have begun gardening, and experienced the satisfaction of seeing plants grow under our hands, even a brief visit to the garden stimulates the urge to pull a weed, deadhead a faded blossom, or move a misplaced specimen to a better spot.

Gardens are valuable tools for many special purposes; many gardeners find them therapeutic on all occasions.

More

The American Horticultural Therapy Association provides its definitions and positions regarding therapeutic gardening.

The American Society of Landscape Architects offers an interesting essay, “The Therapeutic Garden— A Definition.”

Pinterest (which collects photos on various topics from many sources has several unorganized groups on topics related to therapeutic gardens. A search on “horticultural therapy ideas” yields this collection, which demonstrates the wide range of ideas that people associate with “horticultural therapy.”

 

Plants for Rock Gardens

Many different plants could be included in a rock garden. The usual design approach limits plant selection to low-growing varieties, but this is not a necessary constraint.

A brief study of the vegetation on a naturally occurring rocky landscape would help in designing a realistic rock garden for a residential landscape.

Some travel could be required to locate one or more good examples; this could be a pleasant weekend excursion with a clear purpose, especially if one knows where to find rocky landscapes. Ask around!

Once found, rocky landscapes might include one or more trees of various sizes, as well as shrubs and smaller plants. Clearly, proximity to rocks does not limit the size of plants.

A rock Garden in July

A late July scene in the rock garden of the University of British Columbia Botanical Garden; photo by Todd Boland.

The assumption that rock garden plants should be low-growing specimens probably relates to alpine gardens, which have inspired many rock gardens. Alpine gardens feature plants that grow naturally in high-altitude, mountainous areas, which typically have large stones and much gravel, low temperatures, low moisture, and poor soil nutrition. Plants that survive under such conditions might very well be small in overall size and low growing.

Developing an authentic alpine garden, however, involves reproducing the challenging conditions in which alpine plants are found. There are alpine varieties of some familiar garden varieties, e.g., Campanula, Dianthus, Geranium, Phlox, Primula, Ranunculus, Sedum, Sisyrinchium, Thyme. If such plants were to be grown in a moderate climate, in rich soil and with ample moisture, they would respond with more lush growth and greater size than they would in a true alpine garden.

Rock gardens should not be confused with alpine gardens. In fact, rocky landscapes can and do occur in a wide range of climates, with the only common characteristic being exposed rocks. So, in planting a rock garden, the gardener should first select plants that will thrive in the local environment. The Monterey Bay area’s climate supports a wide range of choices.

The rock garden designer still might want to emphasize low growing plants to keep the vegetation in scale with the surrounding landscape and the rock garden itself, and to keep the rocks visible (they might have required a significant investment).

Another consideration is the relationship of the plants to each other. This perspective might lead to developing a plant community, i.e., a grouping of plants that grow together in nature. Other possibilities include a thematic approach, e.g., a white garden or an analogous or complementary color scheme. In our moderate local climate, the designer also might plan for year-round seasonal color, or for interesting contrasts of foliage or structure.

There are many possibilities, but the most successful and satisfying landscape plans always are based on a plan of some description, rather than a series of impulsive decisions.

More

Alpine Garden Society – Plants –This is a thoroughly amazing website, a vast treasure trove of images and information about alpine plants. At the site, click on “AGS Encyclopedia” then on either “Families,” “Genera,” Species,” or “Authors” for encyclopedic information. (I found “Genera” most useful.)

sizedClass-1-second_SAXIFRAGA PANICULATA_Class1-1_ MANNLICHEN, BERNESE OBERLAND, SWITZERLAND JUNE 201228882

 

The image above came from Images/Photographic Competition/Previous Winners/AGS Photographic Competition, 2012 – Winners

The website invites—and requires—exploration to discover its many riches.

North American Rock Garden Society – Another good source of plant images and descriptions. Not as extensive as the Alpine Garden Society’s website, but helpful as an introduction to rock garden plants. At the site, click on “Plants” for the entry to lists and images.

Rock Gardens & Ground Covers A page of unorganized photos submitted to Pinterest. Interesting to scroll through, to see some very good plant pictures, some attractive designs (more or less naturalistic) and some truly bad designs (but that’s one person’s opinion).

Scottish Rock Garden Club – This website provides free access to many back issues of The International Rock Gardener, an excellent publication.

Rock Gardening

Garden renovation projects might include mounds to add visual interest in an otherwise flat terrain, and also to provide drainage and other benefits of raised beds. A particular form of the garden mound is the rock garden, based on a natural or simulated outcrop of rocks.

An outcrop could occur in a flat area, but are most common—and look most realistic when created—on a slope, where erosion over time would have exposed the underling rock formation. If your property includes an area that has a slope of ten degrees or more, and full exposure to the sun, you have a good site for a rock garden. Never mind if it lacks rocks: they can be trucked in from a stone yard.

Lacking a sloped area, the gardener could develop a rock garden on a mound, and should not be reluctant to do so, but should avoid the look of “a dog’s grave,” which results when an isolated bump is placed in a lawn. A mounded rock garden will have a naturalistic appearance when is has substantial size appropriate to the setting, and a backdrop of shrubs, trees, wall or hills.

Another contributor to a natural look is a scree boundary. The base of a natural rock outcrop often will have a loose accumulation of smaller stones and rock chips, called “scree.” So, where sufficient space is available, include a scree bed about two feet wide between the rock garden and the adjacent lawn or pathway. The scree bed should have a foundation of about eight inches of scree compost (1 part topsoil, 1 part compost, 3 parts gravel). An edging would help to contain the stones.

Acquiring and placing rocks will be the most expensive, strenuous and aesthetically challenging part of the project. Here are recommended guidelines:

  • Use one kind of stone, preferably one that occurs naturally in the area. Traditionally, rock gardens use limestone or sandstone, but in the Monterey Bay area Sonoma fieldstone, an igneous rock (basalt or rhyolite), is widely available and popular.
  • Commit to the project. Include boulders (stones too large for one person to move) even though they can be difficult to place in desired positions.
  • Contract with the stone yard deliver materials to as close as possible to their eventual location.
  • Position stones for a natural appearance: larger stones will be uphill of smaller stones; some stones might be close to other stones.
  • Bury stones one-third to one-half of their vertical dimension. Stones rarely are found atop the soil.

A rock garden is just one use of stones in garden design. Stones are also used for walls, borders of beds, walkways or patios. All such uses can be attractive in the garden, partly because of the contrast between the surfaces of stones and plants. Recognize, however, the differences between naturalistic rock gardens and these other uses, in which stones are used as building materials.

More

20 Fabulous Rock Garden Design Ideas —from Decoist.com. These images show fine designs that demonstrate a variety of uses of rocks in the landscape. Not all designs could be called naturalistic.

 

Rock Garden Ideas — 112 images of rock gardens, ranging from naturalistic designs to “whimsical” ideas. Test yourself on whether these designs follow or violate the five design guidelines listed in this article.

Alpine Garden Society – This society is based in the British Isles, where rock gardens first became popular. Gardeners in the United States have developed many rock gardens, but not with the enthusiastic commitment evident in England.

The Rock Garden – Very good how-to article by Alan Grainger, with sufficient information to guide a novice project.  Visit the website, The Alpine Garden for many related garden and plant photos, book reviews and other resources.

Betty Ford Alpine Gardens A large and varied place, designed for visits (not so much for web browsing). This could be the most highly developed public rock garden in the United States.

How to Build Rock Gardens From About.com – This website illustrates a “rockery,” a garden design that is based on rocks, but which does not pretend to a natural look. This might also be called a “dog’s grave.”