Paths to Garden Success

One of my projects during this past week was to install a maintenance path through a deep garden bed, to provide access for weeding, deadheading, organic spraying, irrigation maintenance, and whatever else.

(By the way, my recent call for alternatives to the term “deadheading” yielded an intriguing suggestion: “bloom boosting.” That term is more descriptive than my relatively technical term of “rejuvenation,” and the best one I’ve received. It could catch on!)

A very deep bed should have a maintenance path every four feet, which effectively divides the larger area into beds that are four feet wide and accessible from both sides. That maximum width enables the gardener to reach all parts of the bed without stepping into the bed and compressing the soil.

To avoid fragmenting the appearance of a deep bed, the gardener could form maintenance paths with twelve-inch (round or square) concrete pavers. These are available for as little as ninety-nine cents each, and, when placed behind taller plants, can be unobtrusive.

Maintenance paths could be simply unplanted areas, to be sure, but unpaved pathways could become overgrown and difficult to find. The use of pavers or natural flagstones avoids such problems.

The creative gardener could cast unique (or semi-unique) pavers using purchased or homemade molds. That might satisfy a creative urge, but seems like overkill for something intended to be invisible to visitors.

Pavers also could be used for a walkway for gardeners and their visitors. Such walkways should be at least four feet wide, so the casual visitor could stroll through the garden without watching every step. In larger gardens, wider paths might be well proportioned and would accommodate side-by-side strollers.

There are many possibilities for the surface of a garden path, too many to review here. My paths are not constructed with paver, but with three or four inches of decomposed granite (“DG”) on landscape fabric, with Sonoma fieldstone rocks as edging. This design can be achieved at low cost per foot, but weed seeds, delivered by the wind and the birds, will germinate in the DG. Regular applications of corn gluten, an organic pre-emergent herbicide, can reduce the continuing need to weed the walk.

This use of DG (a coarse sand) resembles a path material called hoggin, which is a mix of gravel, sand and clay that binds firmly when compacted, yet allows water to drain through it. A hoggin pathway (more popular in the United Kingdom than in America) looks attractive and is easy to maintain, just requiring occasional weeding.

Well-designed and well-constructed pathways support both the maintenance and enjoyment of the garden. Planning and building a good path will add greatly to the long-term success of the garden.

More

For a good selection of garden path designs, see “35 Lovely Pathways for a Well-Organized Home and Garden.”

The Web has lots of technical information and video clips on building a garden path, including the selection of materials and the actual construction. Search the web for “design a garden path” or “build a garden path.”

We focus here on the route for a garden path.

When planning the route of a new path, consider both its function and its aesthetics.

The path’s basic function is to support comfortable, efficient and safe movement around the garden, by both the gardener and visitors. The path should connect the garden’s entrance and its exit, and provide good access to the principal features of the garden, e.g., patio, seating area, tool shed, garden art, greenhouse, pond, compost bin, nursery, irrigation controls, etc.

Safety considerations include the following

  • running grade no greater than 4%, i.e., elevation changes no more than one foot for each twenty-five feet, or about one-half inch per foot. (Use steps for greater slopes);
  • cross-slope no greater than 2%, for pedestrian comfort and safe use of wheelchairs;
  • ramps should not exceed 15% (8% for wheelchair use); and
  • surfaces should provide good traction under wet, snow or frost conditions, and should be kept reasonably clean of organic materials, e.g., leaves.

Aesthetic considerations are more subjective.

The appearance of the pathway, determined by the materials used, should relate well to the style of the garden. For example, a pathway of concrete, clay or natural stone pavers will be best in a formal garden environment, while a pathway of sand, gravel or hoggin will look “right” in an informal garden. A pathway of poured concrete would be most appropriate in a public botanical garden or arboretum, where high levels of use by pedestrians, shuttles and maintenance vehicles would be anticipated.

The aesthetics of pathway design also includes subtle issues. Generally, avoid straight-line pathways and right angles, both of which suggest formality and seem incompatible with the experience of strolling through a garden.

Then, ensure that each part of the pathway leads to a destination, e.g., a seating area, an exit, or one of the garden’s features, as listed above. A looping segment of the pathway should be intended clearly to support viewing of all sides of a larger bed. The pathway should neither meander aimlessly or lead to a dead end that requires the visitor to retrace his or her steps.

Finally, the pathway should not expose the entire garden to the visitor’s view, but should be designed to “conceal and reveal” in a managed process. Use the curves of the pathway, in combination with larger plants, to create a series of small mysteries that entice the visitor to discover what lies just out of sight. Then, as the visitor advances along the pathway, reveal the “prize,” which could be one of the garden’s features, listed above, or a specimen plant, nicely presented.

The layout of a garden pathway that addresses both functional and aesthetic concepts successfully can be a challenging exercise, but also can add greatly to the overall success of the garden. Just about all pathway designs can be revised on the basis of experience, so the gardener should feel free to experiment.

Deciding on Dahlias

The dahlia counts among our most satisfying and popular ornamental plants. It grows easily, blooms over a long period, reproduces generously and returns anew, year after year.

Spanish explorers brought the dahlia from Mexico and Guatemala to Spain in the early 1800s, where it became popular throughout Europe. The arrival in 1872 of a new variety, Dahlia juarezii, inspired hybridizers to create the wide range of dahlias from which gardeners can choose today.

The dahlia-growing year has three phases: selecting the plants, planting the tubers, and enjoying the blossoms. The planting season begins after the last frost (after April 1st for the Monterey Bay area, conservatively) and ends mid-June (earlier is better). The Monterey Bay Dahlia Society schedules its annual sale in early April.

The bloom period begins in mid- to late-July, depending on the cultivar, and continues until frost. In this area, we can leave tubers in the ground to sprout in the spring.

The first phase of the gardener’s annual dahlia-growing plan is to select plants to add to the garden. We might indulge occasionally in impulsive gardening, but planning works!

The time to select plants is now. This may be the dahlia’s greatest challenge. The American Dahlia Society recognizes eighteen forms of the dahlia, fifteen colors or color combinations, and nine blossom size categories. In addition, for each form, hybridizers have produced —and continue to produce—many unique cultivars.

Planning for specific plants also involves choosing a suitable location, which for dahlias means full sun and good drainage. In addition, site selection should consider how the size and color of dahlias would relate to nearby plants. The gardener might visualize a “garden vignette,” a setting in which dahlias would complement other new or existing plants.

There are no compelling rules here, except the tried-and-true “tall plants in back” idea, which concerns only visibility. Many combinations of color and form can be successful, so the individual gardener’s creative and aesthetic senses are most important.

After deciding on a spot for dahlias in your garden, you will have until planting time for site preparation: removing or relocating existing plants, amending the soil, etc.

To choose which dahlias to grow in your garden, know the options. An excellent opportunity for this planning is the Monterey Bay Dahlia Society’s 2012 Annual Dahlia Show, which runs from 1:00 to 5:00 on Saturday, August 25th and from 11:00 to 4:00 on Sunday, August 26th. It will be at Soquel High School, 410 Old San Jose Rd., Soquel, CA. At this free event, local gardeners display hundreds of types of dahlias and compete for awards. Knowledgeable volunteers will offer growing tips and answer questions. Dahlia blooms and plants will be available for purchase as well.

More

The following information is from the American Dahlia Society.

Blossom Size

  • AA -(Giant), over 10 inches in diameter
  • A -(Large), over 8 to 10 inches in diameter
  • B -(Medium), over 6 to 8 inches in diameter
  • BB -(Small), over 4 to 6 inches in diameter
  • M -(Miniature), up to 4 inches in diameter
  • BA -(Ball), over 3.5 inches in diameter
  • MB -(Miniature Ball), over 2 to 3.5 inches in diameter
  • P -(Pompon), up to 2 inches in diameter
  • MS -(Mignon Single), up to 2 inches in diameter

Form

  • Formal Decorative – Ray florets (petals) are flat, partially revolute (petal edges roll back), or partially involute (petal edges roll forward). The petals are uniform and regularly arranged, tending to curve toward the stem.
  • Informal Decorative – Ray florets are twisted, or curled, or wavy creating an affect that the petals are not flat. The petals may be partially revolute with their arrangement appearing irregular.
  • Semi-Cactus – The ray florets are broad at the base, straight, incurved or recurved and the ray florets revolute for up to one half of their length.
  • Straight Cactus – The ray florets revolute for more that one half of their length; they also may be pointed, straight, or recurved, radiating in all directions from the center of the flower head.
  • Incurved Cactus – These dahlias also have ray florets that are curved for more than one half of the length but the pointed petals have a pronounced curvature toward the center of the flower head.
  • Laciniated – The split or laciniation should be in proportion to the ray floret length. There should be an overall twisting in the area of the split involute or revolute ray florets, to give an overall fringed effect.
  • Ball – fully double flowers, ball shaped or slightly flattened at the face, and the ray florets are blunt, rounded, or indented, involute for most of their length, fully involute for about one half their length, and normally displayed in a spiral arrangement.
  • Miniature Ball – Same form as ball dahlia , differing only in size.
  • Pompon – Fully double flowers similar to ball dahlias but more globular and smaller in size; also, the ray florets involute for their whole length and fully involute for more than half of their length.
  • Stellar – Fully double, breaking gradually from immature florets to fully developed outer florets. The outer florets should be narrow and involute with a slight recurve to the stem. The less mature florets should possess the same narrow and partially involute characteristic. The depth of the stellar dahlia type should be from one half to two thirds the diameter of the bloom, the greater depth being the ideal.
  • Waterlily – Fully double and symmetrical blooms with a side view that appears to be flat or saucer shaped. The ray florets are openly faced giving the bloom a delicate appearance. The center is closed and dome shaped breaking gradually to four to seven rows of fully developed outer ray florets which are also broad and slightly cupped.
  • Peony – An open centered dahlia with two or more rows of ray florets surrounding the disc flowers (small tubular florets which make up the central part of the flower. Each has a pistil and stamens but generally no other conspicuous flower parts). Ray florets adjacent to the disc flowers may be smaller, twisted, and/or curled.
  • Anemone – Dahlias with one or more rows of ray florets surrounding a center of elongated tubular disc florets. These disc florets should be fully developed and present a domed, pincushion appearance.
  • Collarette – An opened faced dahlia with a single row of uniform evenly spaced compound ray florets in a flat plane surrounding the disc flowers. The petaloids that surround the disc are less than one-half the length of the ray florets.
  • Single – An open faced dahlia with a single row of uniform evenly spaced ray florets in a flat plane surrounding the disc flowers.
  • Mignon Single – Same as single, differing only in size.
  • Orchid – An open centered dahlia with a single row of evenly spaced ray florets in a flat plane surrounding the disc flowers. The ray florets are involute for 2/3s or more of their length and fully involute for at least 1/3 of their length.
  • Novelty Open – Dahlias with characteristics differing from the present classifications. These dahlias will have a disc center.
  • Novelty Fully Double – Dahlias with characteristics differing from the present classifications. These varieties will have a fully double center.

Color

1) White

2) Yellow

3) Orange

4) Pink

5) Dark Pink

6) Red

7) Dark Red

8) Lavender

9) Purple

10) Light Blend – a blending of the lighter tints and tones of pink, yellow,lavender, and other pastels

11) Bronze

12) Flame

13) Dark Blend

14) Variegated – where two or more colors appear on the face of the bloom either in dots, splashes, stripes on narrow lines

15) Bicolor – blooms with two distinctly clear and sharply separated color

Time to Plant a Rainbow

I mentioned recently that the imminent annual rhizome sales by the Monterey Bay Iris Society. If you made notes, you know that the first of two sales happens today, at the Deer Park Center in Aptos. If you didn’t write a reminder to yourself, by the time you read this, you missed it.

Happily, the second sale is a week away, at August 11th at the Aptos Farmer’s Market, located at Cabrillo College. For details, visit http://www.montereybayiris.org.

These sales are very popular: the rhizomes are favorably priced and sell quickly. Their popularity begins with the plants themselves, which most gardeners find both easy to grow and stunningly beautiful. The extraordinary range of colors—and color combinations—that iris blossoms display have earned the plant’s name, which comes from the Greek word for the rainbow.

Iris hybridizers search diligently for new colors, color combinations, patterns and textures, at the same time striving to improve the species in terms of blossom size, number of blossoms, overall form, vigor, resistance to disease and other traits.

The hybridizing process, like that of all flowering plants, seeks to combine the desirable characteristics of two plants. For example, one might have blossoms with very beautiful colors while the other has attractively ruffled blossoms. The hybridizer transfers pollen from the anther of one plant (the pollen parent) to the stigmatic lip of the other plant (the seed parent), plants the resulting seeds and evaluates the progeny. It is up to the plants to produce new plants with a marketable combination of features.

The result of this continuing quest for improvement is an ever-expanding multitude of named varieties and the evolving opportunity for the iris fancier to add to his or her collection. Each year brings new introductions with unique names.

All the new hybrid plants do not combine the desired characteristics as the hybridizer intended. Each trial inevitably yields many new plants that do not improve upon their parents. The hybridizer does not offer such seedling as new named introductions, so we who buy irises for our gardens see only very attractive plants. The “duds” are discarded.

Most hybrid irises are descended from one of just three species in the genus Iris: the German Iris (I. germanica), the Sweet Iris (I. pallida) or the Hungarian Iris (I. variegata), all of which are categorized as “tall bearded” irises. The hybrids of these species number in the thousands—and counting—but the genus includes about 300 species. Gardeners who appreciate the unique form and stunning range of colors of the iris have ample opportunities to look beyond the popular hybrids and explore the long list of naturally occurring species.

More

Iris Cultivation
The websites of the American Iris Society and the Monterey Bay Iris Society provide detailed information on the cultivation of irises.

Mail Order Sources of Tall Bearded Irises (West Coast Growers)

Aitken’s Salmon Creek Garden, Vancouver, WA
www.flowerfantasy.net

Bay View Gardens
(our friend Joe Ghio)
1210 Bay Street, Santa Cruz, CA 95060

Cadd’s Beehive Iris Garden
(our friends Anna & David Cadd)
Healdsburg, CA
(707) 433–8633; caddiris@comcast.net

Fred Kerr’s Rainbow Acres
North Highlands, CA
www.rainbowacresonline.com

His Iris Garden
Merced, CA
www.hisirisgarden.com

Iris Fan, The
Albany, OR
www.theirisfan.com

Keith Keppel
P.O. Box 18154, Salem, OR 97305

Lauer’s Flowers
Independence, OR
lauersiris.com

Napa Country Iris Gardens
Napa, CA
www.napairis.com

Nola’s Iris Garden
San Jose, CA
(408) 929–6307; info@walking-p-bar.com

Pleasant Valley Iris Farm
Vacaville, CA
(707) 451–3367

Snowpeak Iris and Daylilies
Lebanon, OR
www.snowpeakiris.com

Scheiner’s Iris Gardens
Salem, OR
schreinersgardens.com

Superstition Iris Gardens
Cathy’s Valley, CA
community.webshots.com/user/rickt103

Sutton’s Iris Gardens
Porterville, CA
suttoniris.com

Wildwood Gardens
Molalla, OR
www.wildwoodgardens.net

Mail Order Sources of Species Irises
Note: Most growers carry at least a few species irises in addition to the ever-popular hybrid tall bearded irises (called TBDs). The growers listed below place greater emphasis on the many alternatives to the tall bearded irises.

Draycott Gardens (beardless irises)
Upperco, MD
www.draycott-gardens.com

Eartheart Gardens (Siberian & Japanese Irises)
Harpswell, ME
www.EartheartGardens.com

Ensata Gardens (Japanese Irises)
Galesburg, MI
www.ensata.com

Iris City Gardens (Siberian, Louisiana and other beardless species)
Primm Springs, TN
222.iriscitygardens.com

Iris Haven (Louisiana Iris)
Australia
www.irishaven.com.au

Wildwood Gardens
Molalla, OR
www.wildwoodgardens.net

 

Finding Rare Plants

More by chance than by intention, I discover plants that are fairly rare in residential gardens. Invariably, my discoveries are plants that are native to dry summer climate regions, because it is that population within which I seek plants for my own garden.

Incidentally, gardeners who search for plants from climates other than their own garden’s climate are called “zone deniers.” Gardening with plants from exotic zones might appeal to one’s sense of adventure but it involves more challenges than I would enjoy.

Here are three attractive rare plants that I have encountered recently

Blood Flower (Haemanthus albiflos).

Image from Wikipedia (http://en.wikipedia.org)

An evergreen South African bulbous geophyte, related to the Amaryllis. The generic name translates as “blood flower,” reflecting the red flowers of the first species found, H. sanguineus. The specific name of the plant I acquired from the Monterey Bay Area Cactus and Succulent Society means “white flower,” so I now have a white-flowered Blood Flower. The plant is sometimes called “Elephant’s Tongue” for its leaves or “Shaving-brush Plant” for its unusual flowers. This is a very low-growing plant, suitable as a rock garden specimen or indoor plant.

Source (among others): Telos Rare Bulbs <http://telosrarebulbs.com>

Blue Chilean Crocus (Tecophilaea cyanocrocus).

Image from The Scottish Rock Garden Club (http://www.srgc.org.uk)

A very rare geophyte that is native to Chile, but presumed extinct in the wild since 1986. Plant hunters rediscovered it in 2001 and brought back corms. It has been propagated in botanical gardens and is slowly becoming available commercially. The plant, a member of the iris family, has blossoms that resemble those of the Crocus, a different member of that same family. Its flowering stems grow up to four inches tall, and the deep gentian clue flowers, with a whitish center, are just one inch across. In the northern hemisphere, it blooms February to March.

Source (among others): Brent and Becky’s Bulbs (https://store.brentandbeckysbulbs.com)

Golden Fuchsia (Deppea Splendens).

Image from http://www.strangewonderfulthings.com

Another plant that probably is extinct in the native cloud forests of southern Mexico (Chiapas) and Guatemala. This plant flowers in late summer with spectacular clusters of pendulant golden yellow tubular flowers topped by violet-red calyces. Even its leaves are attractive. The plant is not a Fuchsia, but a member of the very large coffee family. One of its many relatives is the Gardenia. Its seeds were first brought to northern California in 1981 and distributed selectively. Most of the plants grown from these seeds were killed by frost, but a few plants survived in the San Francisco Botanical Garden and the Huntington Gardens, and are now slowly becoming available commercially.

Source (among others): Annie’s Annuals & Perennials (https://www.anniesannuals.com/)

Avid gardeners could select these or countless other uncommon plants to enjoy for their beauty and rarity. Not all rare plants are attractive or even garden-worthy, so plants that meet those criteria and will also flourish in our dry summer climate are welcome treasures.

Enjoy your own rare plant discoveries.

 

When Less is More

My garden is doing well. Perhaps too well.

Several plants in established planting beds have grown to merge with adjacent plants to create a lush effect that I have often admired. Garden magazines often feature residential landscapes with masses of plants in close proximity, so that their colors and textures blend visually to provide an impressionist picture.

When we follow the parallel with fine art, the impressionist approach to garden design contrasts with the realist approach. The impressionist focuses on the overall elements of light, color and movement (all important in a garden) while the realist features the botanical characteristics of individual plants (also important in a garden).

The difference between these approaches could be just a function of time. Plants in a new bed are widely spaced, to provide room to grow, and plants in an older bed will have reached their mature size and occupied the spaces from their neighbors.

Let us agree that both approaches are valid and can be aesthetically pleasing.

Still, we can ask, “What circumstances make the impressionist approach successful?”

First, the choice should be intentional rather than an uncontrolled result of plant growth. This relates to the basic rule, “right plant, right place.” If a plant has grown to overshadow its neighbors or intrude on the walkway or simply become too large for its place in the garden, it no longer contributes to an impressionist ideal. It’s just a garden thug.

Second, the plants should be compatible with each other. They should flourish under similar conditions of light exposure, moisture levels, soil texture, site elevation, wind force and any other contributors to growth and health.

Third, the plants should be complementary in appearance. This could be an elusive criterion because of differing opinions on plants that look good together. The important variables for most gardeners are blossom color, leaf texture and overall size.

Whether any given pair of plants “look good together” is a personal preference, and, any two plants could be regarded as a good combination. I have rarely if ever read that any two plants look really bad together. Instead, their combination will be described as “dramatic” or “surprising” or “bold” or even “shocking” (but in an approving manner).

We might ask this question of the realist approach, but plants are farther apart from each other, by definition, so they it is less important that they look good together. Gardeners who prefer this approach are those who appreciate the natural forms of plants and have interest in their unique qualities.

Successful impressionist designs can be challenging.  I admit that areas of my garden are undeniably overgrown, and have already begun a long-term process of removing or relocating the thugs and featuring the prizes.

Enjoy your garden.

More

The most famous impressionist gardener was Claude Monet, whose garden at Giverny, France is well known and greatly appreciated. The New York Botanical Garden has a current exhibit in a conservatory environment, continuing to October 21, 2012. The exhibit includes photographs by Carmel artist and gardener, Elizabeth Murray, whose best-selling book, Monet’s Passion: Ideas, Inspiration and Insights from the Painter’s Garden, has been republished in a 20th anniversary edition (Pomegrate, 2010).

Information about the Monet exhibit is available on the NYBG website.

Contemporary garden designer Piet Oudoulf has created many lush “gardenscapes.” Several of his designs are available for study here. Look, in particular, at the Pensthorpe garden for a good example.

Finally, for examples of bold plant combinations, see Thomas Hobbs book, Shocking Beauty (Periplus Editions, 1999).

Divide and Plant Spring Bulbs

Are you thinking about dividing or planting bulbs now, in preparation for next spring?

I must insert the obligatory reminder that we often use the term “bulbs” to refer to true bulbs, as well as corms, rhizomes and root tubers, i.e., all plants with underground storage organs. Collectively, such plants are correctly called geophytes.

This is the season for dividing and planting spring-blooming geophytes. Dividing can be done annually, but is done most efficiently on a three-year cycle because in that time they can become too crowded to bloom well.

Daffodils are among the first of the geophytes to finish their cycle: their leaves have dried and dropped by July. If the leaves are still on the ground, the location of the bulbs will be evident. Otherwise, digital snapshots taken when the leaves are still green will provide useful clues of their locations. Plant daffodil and other bulbs about three times as deep as the bulbs’ diameter.

Irises should be divided and planted during the period from July through September. This year, the Monterey Bay Iris Society’s annual rhizome sales will be on August 4th at Deer Park Center and August 11th at the Aptos Farmer’s Market. For details, visit http://www.montereybayiris.org. Plant iris rhizomes shallowly, with their top surfaces exposed to light and air.

The tall bearded iris is the most popular variety of iris, but there are several other interesting species in the genus Iris, and many hundreds more in the iris family.

Another popular geophyte, the Gladiolus, should be divided in the fall, after the leaves have turned brown. Watch for gladiolus rust, a fungal plant disease of quarantine significance that first appeared in northern California in 2010. This disease is associated with the Gladiolus, but it also affects other genera in the iris family (Iridaceae): Tritonia, Crocosmia and Watsonia.

The fungus’s botanical name, Uromyces transversalis, provides a clue to its identification: pustules on both sides of the leaves tend to run across the width of the leaf, i.e., transversely.

If you spot these symptoms in your garden, seal the entire plant, corms, stems and leaves, in a plastic bag and discard it in the green waste (not in your compost bin). If gladiolus rust doesn’t appear in your garden, consider yourself fortunate.

Commercial growers can use systemic fungicides to control gladiolus rust, or to salvage the corms of infected plants, but these are toxic chemicals not suitable for use in residential gardens.

When dividing and replanting your healthy “glads” plant the larger corms six-to-eight inches deep, to reduce or eliminate the need to stake the plants.

Preparations at this time of the year will yield a delightful display in the spring.

Enjoy your garden.

More

Here is an example of gladiolus rust, showing the pustules arrayed across the leaf’s surface. This pattern is not always this clear. For other examples, search Google Images for “gladiolus rust.”

Gladiolus Rust

This fungal infestation deserves some concern, but it might not appear in your garden. Unless and until it does, the need to divide your geophytes when they get crowded, or to add new plants to your garden, is a higher priority.

When dividing geophytes, a garden fork is easier to use and less likely to damage the plant, compared to a garden spade. The task also is easiest when the soil is fairly dry and will fall away readily from the bulbs, corms or rhizomes.

Separating bulbs and corms is relatively obvious, but separating iris rhizomes is more involved. With each season, the original rhizome produces new rhizomes, which grow out like a new generation. After three years (when dividing is needed), there will be a cluster of rhizomes, which each new generation growing out of the previous generation. Snap the rhizomes apart and discard the older generations. The youngest generation of rhizomes will produce new plants.

Digging rhizome

1. Dig the entire clump gently out of the ground with a spading fork or shovel.

Dividing the New and Old Rhizomes

3. Cut off the outer rhizomes. Discard old center portion without leaves. Cut out any signs of rot and dust with fungicide as a precaution.

Planting Rhizome

4. Plant each division as shown by pressing the rhizome into a mound in the planting hole, with the top of the rhizome almost at soil level. Fill in and firm the soil.

More Timely Tasks – Deadheading

Deadheading flowering plants ranks among the easiest and most productive tasks in the garden. This task does not require precise timing, just whenever blossoms have faded and the gardener wants to promote new blossoms.

Deadheading is the process of removing faded blossoms. The purpose of the blossom of course is to attract a pollinator to bring pollen from another blossom to fertilize an egg cell and thus to produce a fruit with seeds.

In some cases, the gardener wants the fruit to eat (think apple tree) or wants the seeds to grow into more plants (think poppies). In other cases, however, the gardener simply wants the beauty and fragrance of more blossoms.

Deadheading can be a relaxing and satisfying exercise for the gardener, but it involves frustrating the plant’s reproductive purpose. The plant doesn’t experience frustration or any other emotion. Instead it responds by producing new blossoms, still in pursuit of its goal to make more plants. That means more blossoms, for the gardener’s pleasure.

Incidentally, we need a new term for this gardening process. “Deadhead” has been used for many years, possibly to suggest “head back dead blossoms,” but it sounds gloomy and doesn’t indicate the purpose of action. Something like “rejuvenate” (to make young again) would be better, but there are other options. Your ideas will be welcomed!

The basic technique is to remove the spent flower just above the first leaf below the flower head. This removes a section of stem (which might be unsightly) and encourages new growth from the leaf node.

The leaves of rose bushes occur in sets of three, five or seven, with larger sets lower on the cane. The standard advice has been to cut just above the first set of five or seven leaves. Some experts recommend cutting above the second set of five or seven leaves. In both approaches, the apparent intention is to encourage new growth from a stem that is strong enough to support a blossom.

Newer research has shown that roses will flower more prolifically when the gardener removes old flowers by cutting just above the first set of three leaves, rather than lower down on the stem. Try that on your own roses. Mark the “test cases” with a colorful string or ribbon and observe the effect.

Rejuvenating roses in this way can be combined with shaping the plant’s overall form, opening the inside of the bush to improve air movement, and heading back wayward canes. These goals often require cutting lower on the canes.

Next week: dividing daffodils, irises and other spring geophytes (they are not all “bulbs”). These tasks are needed at this time of the year but only on a cycle of about three years.

Enjoy your garden.

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Good Timing for Good Gardening

If you have an oak tree or an apple tree, this column is for you. If you have neither, read on nevertheless for seasonal ideas that generalize to other gardening processes.

The first concept of value is that timing is an essential strategy for successful gardening. Our plants operate on a natural cycle that waits for no gardener.

Apple Trees

Right now (the end of June) is the year’s last opportunity to maximize the yield of your apple trees. This time-sensitive task involves thinning your apples to allow each of the remaining apples to develop its greatest size and sweetness.

You can begin thinning apples a short time after the blossom drop when small apples appear, up to when the apples are no larger than table tennis balls. Once they grow beyond that size, thinning is not as effective.

Apple trees will thin themselves: the “June drop” is Nature’s way to produce larger fruits and avoid broken branches.

Commercial growers use chemicals for thinning, but hand thinning is practical for small home orchards. The largest young apples are the “king apples,” from the earliest blossoms. Use pruners or small clippers to remove the smaller fruits to so that the remaining fruits are about six inches apart. Let them drop then rake them for disposal. This might seem brutal but the harvest will be gratifying.

Oak Trees

During the July–November period, California Oakworms (Phryganidia californica) attack our Coast Live Oaks (Quercus agrifolia). The infestations vary in severity, but in a bad year the caterpillar-like larva of the Oakworm can defoliate a tree severely and provide a nasty display for the homeowner as well.

Some experts say Oakworm attacks are natural occurrences that rarely cause permanent damage to otherwise healthy oak trees. During last Saturday’s Garden Faire, however, I spoke with James Neve of Tree Solutions, who says homeowners need not suffer the presence of these insects and their droppings (frass), and their trees need not suffer defoliation. He recommends watching for the presence of oakworms in mid-July by placing a white paper plate under the tree’s branches and checking for frass. If the pests show up, consider whether spraying or injecting a biological control would be indicated.

Tree Solutions sprays with “Bt.” (Bacillus thuringiensis) or Pyrethrum (derived from Chrysanthemum flowers) or injects with Abamectin (derived from a soil bacterium). The University of California’s Integrated Pest Management program recommends these sprays and also a commercial product, Spinosad. A regular reader of this column reports good results with Spinosad. Most garden centers have these controls and spray equipment for do-it-yourselfers.

Other timely tasks: deadhead your roses, propagate your favorite woody plants from softwood cuttings, and above all, hydrate your plants during these hot and dry days.

More

For good, reliable information about the California Oakworm, visit the University of California’s Agriculture and Natural Resources website by clicking here.

For the commercial website of Tree Solutions (serving the Monterey Bay area), click here. (This is a free plug for a good business.)

Enjoy your garden.

Rock Gardening

In the garden, one thing always seems to lead to another.

I began by thinning one plant that had begun to crowd a bed in my garden. The plant is the Rain Lily (Zephyranthes candida), a low-growing bulb in the Amaryllis family, native to South America. It has grassy foliage, evergreen in the Monterey Bay area, and six-petal blossoms, white with a pink wash. (Pink blossoms are more common in the genus.)

After a few seasons in the ground, the Rain Lily generates many small bulbs and spreads happily. My original one-gallon clump expanded to fill nearly half of a semi-circular bed about thirty-feet in diameter.

I gathered hundreds of bulbs to share on June 23rd through the Garden Exchange at The Garden Faire (thegardenfaire.org).

That project created open space in that prominent front yard bed, and the opportunity to rethink its design. A rock garden seemed an obvious choice: the bed is already mounded and has a few largish boulders.

My preliminary inquiries into rock garden design revealed that this bed doesn’t qualify as a rock garden, but is instead a “rockery.” A rock garden has particular soil, rocks, and plants; a rockery is simply any planting bed with decorative rocks.

Serious rock gardeners study instances in which plants grow in a rocky environment. This occurs typically in a mountainous region, which will have high elevation, rocky ledges on sloping sites, rock outcroppings on more level land, and crevices, which are narrow, soil-filled spaces between rocks. The soil in such regions typically will be poor in nutrients and fast to drain. The climate usually will be windy and marked by much sun exposure.

The plants in a natural rock garden will have evolved to survive in those relatively hard conditions. The classic rock garden plants are called “alpines,” meaning plants that grow in The Alps, one of the great mountain range systems of Europe. These plants could be herbaceous or woody, and grow up to about one foot high.

Another category of rock garden plants includes small rock (“saxatile”) plants, which grow in rocky sites at lower elevations. These plants are easier than alpines to grow in most residential gardens because the gardener doesn’t need to recreate the uncommon conditions of a mountainous environment.

A popular feature for rock gardens is the scree bed, an area of loose rocks and stones that might occur at the bottom of a slope, perhaps deposited there by a landslide. A larger rock garden might have a sand bed, an acid heath bed, an “alpine meadow, or a boggy area beside a pond or stream.

A rock garden could succeed in a small setting as well, making this interesting naturalistic design concept adaptable for placement in gardens of all sizes.

More

A small rock garden could be created in a container. An appropriate container would be a hypertufa trough, which you can build yourself. Here are instructions from Fine Gardening magazine.

If you have larger project in mind, take the time to research the basic concepts, to be sure you are on the right track and won’t end up with a rockery instead of a rock garden. There are good books on the subject. Here are three that are available on Amazon.com:

Rock Garden Design and Construction, by North American Rock Garden Society (2003)

The Serious Gardener: Rock Gardens (New York Botanical Gardens), by Ann Halpin and Robert Bartomonei (1997)

The Rock Garden Plant Primer: Easy, Small Plants for Containers, Patios, and the Open Garden, by C. Gray-Wilson (2009)

Anatomy of the Garden

Many gardens begin as level rectangles, with a residence more or less in the middle. It doesn’t have to be that way.

If your garden has natural changes of elevation or an irregularly shaped boundary, or both, you could have an interesting context for your garden design.

Dramatic departures from the level of course could be more challenging than inspiring. Workers on steeply sloped vineyards in Germany’s Rhine Valley hold on long ropes to keep from tumbling into the water.

Likewise, an oddly shaped plot could be more trouble than help. Municipal regulations generally prohibit building on small parcels of very unusual form, but such a parcel could accommodate a community garden.

If your garden amounts to a level rectangle, and consequently lacks interest, consider your options for creating elevation changes.

Below-grade elevation change possibilities include a swimming pool, a naturalistic pond, a bog garden (more shallow than a pond) and a rain garden (which collects rainwater and lets it seep into the ground). A swimming pool is mostly a recreational resource, but the other three offer interesting gardening possibilities.

For very large parcels, another below-grade option is the ha-ha. This is a ditch between a garden and a natural area, intended to keep domestic or wild livestock from straying into the garden. The ha-ha typically runs across the line from the residence to the natural area in the distance.

Above-grade elevation changes include raised beds, berms, terraces and sculpted landscapes.

Raised beds are usually rectangular, rising only a few inches above grade, primarily to improve drainage. They could be simple low mounds or might have low walls of wood or other materials. A raised bed also could be about table height, to raise the planting surface for the gardener’s convenience. Such beds are sometimes made for accessible gardening by gardeners with physical limitations.

Raised Beds - Corten

Berms are like large raised beds. They generally are eighteen to twenty-four inches high, curved for a natural look, four or five times as long as wide, and with sloping sides. They could provide higher quality soil (imported), superior drainage, or just visual interest.

For a short article on creating and using berms in the landscape, click here.

Terraces are similar to steps, and, like steps, provide one or more level areas to ease the transition from one elevation to another. They also have aesthetic value when well designed, and can improve the visibility of ornamental plants.

To view an unusual example of a terraced landscape (a rice field in China), click here.

Sculpted landscapes, above- or below-grade, are typically large-scale imaginative earthen constructions intended primarily for visual interest.

A fine example of a sculpted landscape can be seen at the WiIlliam J. Clinton Presidential Center (click here).

These possible elements of the landscape are not difficult or very expensive to accomplish, and could transform a flat rectangular garden into an interesting landscape. They also offer a fine opportunity for creativity in garden design, complementing the core activities of plant selection and placement.

Enjoy your garden!

Click to Enlarge

These clustered raised beds are made of Corten steel for long-term use.