A Cautionary Tale About Ivy

 Ivy brings a combination of pleasure and pain to the garden, and the potential to surprise gardeners who do not pay attention

Forty years ago, when I moved to my current residence, the property had a generous crop of English Ivy (Hedera helix). This most common species of the genus Hedera has some appeal in the garden. The Royal Horticultural Society has honored fourteen cultivars of H. helix with its Award of Garden Merit, reflecting the plant’s apparent good behavior in England’s climate.

Despite its British credentials, H. helix grows rampantly on the west coast of the United States. Washington and Oregon have listed it as a noxious weed. California’s Department of Food and Agriculture has not yet listed this plant as a noxious weed, but hopefully is considering that action. 

This plant had covered much of my new garden, grown into some shrubs, and overwhelmed a large evergreen tree. We removed the tree, with great regret. After several months of hacking at this invasive plant and uncounted ivy hauls to the local landfill, we had it under control. During the following years, we pulled many sprouts and still do today. The more recent sprouts probably began with bird visits, but it is not impossible that dormant ivy seeds have been lurking in my garden for decades, awaiting a taste of moisture and sunlight.

More recently, perhaps five years ago, a variegated cultivar of Algerian Ivy (H. algeriensis) caught my eye, and I planted a small amount near the base of a chimney as a groundcover. All ivies grow horizontally, and are often selected for groundcover duty. My willingness to give this plant another chance in my garden reflects both short memory and persistent optimism.

In the same area, and with similar optimism, I installed a Big Mexican Scarlet Sage (Salvia gesneriiflora). This plant quickly grew well above ten feet in height (it can reach twenty feet high in the mountains of northeastern Mexico) and spread to four separate shrubs.

These beautiful but huge plants concealed the ivy’s relentless spread. The Algerian Ivy/Big Mexican Scarlet Sage collusion continued for weeks, until the enormous salvia finished blooming, and became ready for renewal pruning (i.e., cutting it to the ground).

That drastic action revealed that the ivy had discovered the chimney that rises about thirty feet beside the house, and used it aerial roots to grow to the top of the chimney and spread in both directions across the side of the house. This growth had not been impossible to observe, but the tall shrubs close to the pathway effectively screened the situation from view.

There’s a certain charm to ivy-covered walls, but the plant eventually can cause damage and rot, and harbor unwelcome wildlife. My best choice was to have the ivy pulled down, expecting that it would take down some of the thin-brick veneer, which it did.

There is no simple solution to ivy on the house and chimney.

The next steps of this project include reattaching the missing pieces of the veneer, removing the ivy and all but one specimen of the Big Mexican Scarlet Sage, and keeping it pruned to appropriate size.

Then, the project includes shopping for plants to re-landscape the area. The UCSC Arboretum’s Fall Plant Sale will be a fine opportunity to acquire California native plants for this project. The sale begins at 10:00 a.m. tomorrow (Saturday, October 13th).

Lesson learned: if you plant any variety of ivy in your garden, check occasionally to make sure that it is growing only where you want it to grow.

Glorious Geophytes for the Garden

Right now is a good time of the year to plant spring-flowering bulbs. There are many available varieties for venturesome gardeners to consider, and we regularly recommend trying unfamiliar botanical treasures. Today’s column features daffodils, which could well be the most popular and most frequently hybridized of the geophytes.

‘King Alfred’ Daffodils

Here are reasons for including daffodils in your garden.

Really Beautiful

Many flowers are delightful in the garden, and many gardeners have their favorites, but just about everyone enjoys daffodils, especially when they declare the arrival of the spring season. Daffodils have graceful stems, attractive foliage, and unique blossoms. Trumpet daffodils, the most familiar division within the genus Narcissus, have blossoms that feature the trumpet-shaped corona surrounded by six petal-like tepals, which form the perianth. The corona and perianth might have the same color, or different colors.

Numerous Hybrids

A very large and growing number of hybrid daffodils are available through garden centers and mail order nurseries. Many plants are yellow or white, or combinations of those colors; hybridizers have introduced cultivars with green, pink, orange and red elements. There are interesting and pleasing color combinations for various tastes.

The growing number of hybrids includes variations of shapes, particularly in the coronas that might be single or double in form, or might have ruffled or frilly edges.

There are also varieties that bloom in at various rtimes, as early a late December and as late as early, mid- or late spring, so with a little planning you can create an extended display.

Perennialize Themselves

During their growing season, many hybrid daffodil bulbs form side bulbils that develop new bulbs and provide more flowers in the following season. A clump of daffodils will increase in sixe from one season to the next. In time, the clump can be come crowded, and the gardener can dig up the bulbs for replanting over a larger area, or gift them to friends.

Naturalize Themselves

Some varieties will develop seeds and sow them naturally to form additional populations of plants Over a few seasons, they can spread throughout a meadow area, providing a stunning display.

Free of Pests and Diseases

The bulbs and foliage of daffodils are poisonous to most pests, because all parts of the plant includes the toxic chemical, lycorine. Consequently, the plants have minimal problem with deer, gophers or other rodents. If such pests tend to favor your garden, daffodils will provide a fine display without the expectation that plants will disappear when you’re not looking.

Daffodils are not immune to diseases, and basal rot and fungi could attack the plants, as will as nematodes, bulb flies, or viruses. However, plants grown in good soil with good drainage, and regular care generally will resist such difficulties. The references listed below include helpful information about managing such problems.

Easy to Plant

Daffodil bulbs are planted three times the width of the bulb apart, three times the width of the bulb deep. They can be planted singly, with a trowel or other tool, or in groups by removing the desired amount of soil from the planting area, positioning the bulbs, then replacing the soil. Each gardener has a favorite planting method. In any case, planting a large number of daffodil bulbs can be accomplished quickly.

For more information, here are recommendations of Becky Fox Matthews a past president of the American Daffodil Society:

The American Daffodil Society – The ADS is :The AmericanCenter for Daffodil Information” providing rich resources on its website.

Daffseek – A online photo database with an incredible amount of features (different languages, photos from all over the world, daffodil genealogy and more), made free to the public by the American Daffodil Society;

Daffnet – A discussion forum for For people interested in growing, showing, or hybridizing daffodils

Dafflibrary – Books, articles and journal about daffodils

Dafftube – Slide presentations and video recordings, many of which were presented originally during national or regional meetings of the American Daffodil Society.

Many thanks to Becky Fox Matthews for sharing these links.

Another useful source of information is the website of England’s The Daffodil Society. The Society was established in 1898 as the specialist society of Great Britain for all who are interested in the Genus Narcissus

 Daffodil bulbs will be available now, and through most of the fall months from local garden centers and several mail order nurseries. Several mail order nurseries throughout the United States will offer daffodil bulbs. An Internet search for “daffodil bulbs” will list several sources.

Many gardeners will favor west coast suppliers on the premise that they grow their bulbs under conditions like those of the local area.

In addition, I will list Brent and Becky’s Bulbs, located in Gloucester, VA, not the west coast. This family business began in the early 1900s as a daffodil specialist and has since grown to offer over 1,000 varieties of bulbs. Daffodils continue to be their favorite product, and they offer many beautiful cultivars. Their website also offers solid advice on cultivation. Click on the menu for “Media.”

If you don’t already have daffodils in your garden, this is the time to select and order cultivars that speak to you, and plant the bulbs in preparation for a delightful display in the spring.

Color Combinations in the Garden

Combining floral and foliage colors can be an enjoyable and challenging aspect of garden design. The plant kingdom offers a vast range of possible color combinations, including mixes of the various shades of green.

When planning floral color combinations in the garden, a basic consideration is to select plants that will display their colors at the same time. This issue alone can require compiling notes regarding the bloom periods of plants under consideration, drawing on reference materials such as Sunset’s Western Garden Book.

In addition, the selected plants should have similar requirements for exposure, irrigation, and drainage.

Then, it will usually be desirable to select plants of similar size, so that the blossoms will be in fairly close proximity for optimal effect.

Once the gardener has satisfied these placement and cultivation considerations and has identified a good number of candidate plants, the focus can be on deciding the actual color combinations.

Unless the gardener has a natural gift for visualizing and evaluating color combinations, a color wheel is a useful tool for combining colors in a systematic manner, presenting the spectrum of colors in the familiar sequence of red, orange, yellow, green, blue, indigo and violet (ROYGBIV). They vary primarily in the range of hues presented. A very basic wheel will show just the three primary colors: red, yellow, blue. A more advanced wheel will include the secondary colors: green, orange, purple. An even more detailed wheel will include the six tertiary colors, which are created by mixing primary and secondary colors.

A search of the Internet will produce numerous examples of color wheels for convenient reference in planning color combinations in the garden.

Color theory can be a lengthy study for visual artists and others seeking to appreciate the subtle relationships among colors.  Most gardeners will need only familiarity with the basic color relationships on the color wheel: complementary (opposite colors), analogous (adjacent colors), triadic (three colors evenly spaced), etc. For illustrations of these and other relationships, search the Internet for “color harmonies.”

Real-world combinations might be reflect one of the formal color harmonies, but are as likely to be only a rough approximation. For example, this photo shows a chance mix of a blue-purple salvia blossom and a pink/white geranium blossom. This is a roughly analogous combination, but because the color green adds to the display, it qualifies as a roughly triadic harmony. In any event, if it pleases the gardener, it’s a success!

Salvia and Geranium combine pleasing colors

Another example of a chance mix shows succulent foliage in various shades of green. This too is a roughly analogous combination based on a small sample of the many greens that appear in many gardens.

Succulents provide several green hues

Here is a brief reality check on color combinations in the garden.

  • Creating classic color harmonies requires lots of study to select plants with similar cultivation needs, compatible sizes, and the “correct” floral or foliar colors.
  • Many plants will present pleasing combinations of colors virtually by chance. While beauty is in the eye of the etcetera, it’s difficult to imagine mismatched colors in nature.
  • Garden magazines often include breathless excitement over apparently random color combinations, and describe them with verbiage about their inspired creativity,

If you discover two or more plants that would provide a good mix of colors in your eyes, move them together or keep them together, and enjoy the effect. Garden design by the book can be time-consuming and frustrating, while botanical serendipity can be a delight.

Enjoy your garden!

Strategic Use of Specimen Plants

Recently, we focused on three basic priorities for landscaping: develop a short list of plants, install significant numbers of each kind of plant, and select some unfamiliar plants that will fit into your plan.

A complementary strategy emphasizes the strategic use of specimen plants, which are “unusual or impressive plants grown as a focus of interest in a garden.” A specimen can thought of as an example of a category, but

A plant could function as a specimen plant if it is sufficiently large, especially showy, striking in form, or quite unusual. Note that a plant doesn’t qualify as a specimen plant simply by being an isolated instance of some plant. In other words, a garden of single examples of various plants does not work as a landscape of specimen plants. 

Conversely, a plant that works as a specimen because it is large, showy, striking or unusual probably would not work as a component of a mass planting. Instead, a specimen plant complements a mass planting.

Many plants could qualify as a specimen plant. Garden designers often will choose a tree of appropriate size as a specimen plant. Japanese maples, for example, are popular selections for this purpose.

The placement of a specimen plant contributes significantly to its effectiveness. In many cases, the specimen will succeed best as a contrast to a fairly large grouping of plants, especially foliage plants, e.g., hedges.

A “large, showy, striking or unusual” plant that is apart from other plants also could function as a specimen plant.

As an example from my garden, we have a Kennedia beckxiana ‘Flamboyant’, which is an evergreen climber in the Pea Family (Fabaceae), and one of the UCSC Arboretum’s Koala Blooms Australian Plant Introductions. The plant’s common name, Cape Arid Climber, refers to a region in western Australian.

Kennedia becksiana ‘Flamboyant’ climbing on a stairway

The plant’s generic name honors a British nurseryman, John Kennedy, and its specific name honors Gustav Beckx, a 19th century Belgian consulate General in Australia.

It earns the variety name ‘Flamboyant’ with its 2-inch long orange-red flowers with a showy large lime-green central spot at the base of the reflexed keel petal.

Kennedia beckxiana blossom (Wikimedia photo by Christer Johannson via Creative Commons)

I acquired a five-gallon plant about a year ago from the Arboretum, and installed it to climb on a stairway. It has grown vigorously there, and will soon reach its mature height of ten feet.

My online research into the cultivation of this robust plant suggests that it should be cut back heavily after flowering to prevent invasive growth.

Given its prominent location and showing blossoms, my Cape Arid Climber will hold its own as a botanical focal point.

Look for a spot in your garden where a specimen plant could attract the eye and add interest to your landscape. You might have a fine selection already in place, or one that could be moved to such a special location. If you have “spotted the spot” but don’t have a specimen plant in hand, you can anticipate the pleasure of choosing one for your garden.

Mark Your Calendar

The Monterey Bay Area Cactus & Succulent Society will hold its Fall Show & Sale on September 29th and 30th, in nearby San Juan Bautista, where there is enough space for Society members to fill some eighty tables with fascinating plants for sale or display. We’ll have full details about this event in next week’s Home & Garden section, so be sure to schedule the date for this opportunity to acquire succulent plants for your landscape.

Gardening in Containers

Planting in containers can be a complement to planting in the ground, and it has multiple appeals:

  • alternative to garden space that’s limited (or lacking entirely);
  • opportunity for creative combinations of pots and plants;
  • supports either long-term or seasonal displays;
  • freedom to hide pots with plants after blooming;
  • design strategies for paved areas, like decks and patios;
  • ideal use of wide stairways; and
  • invites large and dramatic arrangements;

Container gardeners soon develop their personal likes and dislikes, but if this approach is new to you, here are ideas to consider.

Plan plants and pots as complements: One method is to choose a container that you like, and then find a plant that would work well with it. The reverse strategy can work too, but there are more plants than pots, so it’s easiest to find the right plant for a given pot. Find complementary colors, textures, and sizes. (One rule of thumb: the plant ‘s mature height should be about twice the height of the container.)

Think big pots: For a striking presentation, select large pots. A collection of one-gallon plastic nursery pots will minimize cost, but will also minimize impact. Smallish decorative containers, even when individually attractive, still under-sell the horticulture. Big pots produce big results, and provide more root room and hold more moisture between watering sessions.

Think multiple pots: Just like planting in the ground, mass effects can be pleasing to the eye and satisfying to the soul. A substantial array of containers can present an eye-catching display. Three is better than two, and, given lots of available space, fifteen is better than twelve. Multiple-pot displays could emphasize annuals or perennials, and can be particularly effective with bulbs.

Plan the overall look:  It’s too easy to accumulate both plants and pots one at a time, which leads to a confusing conglomeration. Such groupings reflect piecemeal landscaping, which is all too popular and ultimately minimizes bang for the buck. The first step in planning for multiple pots emphasizes the overall effect, even when limited time and resources requires building the display over weeks or even months. The plan should encompass the style of the containers. They need not all be the same, but they should work together. A Talavera planter probably will look out of place among several terra cotta pots. The plan also should also consider blossom color combinations, e.g., complementary, analogous, triadic, etc. Search the Internet for “color harmonies.”

Plan individual containers: An important difference exists between a floral arrangement, and a container that plays a role in a larger display. When planning a standalone display, the “thriller, filler, spiller” design works fine. When planning for a big, dramatic effect, however, plant each container with one type of plant in one color. And fill the containers: for example, a 12-inch wide pot can accommodate up to 30 bulbs. A more timid installation will look, well, timid.

Consider the passage of time: When building a display of seasonal plants, keep their bloom period in mind. When blooms have faded, move the containers out of sight and bring in different, ready to bloom containers. An intermediate approach involves installing layers of bulbs with successive bloom periods. This requires some planning, but the extended display can be gratifying.

Large-scale container planting takes some research. If you are considering a display of bulbs, right now is the time to order bulbs to be planted in the fall, for spring blooms. One good online resource is Brent & Becky’s Bulbs. I’ve had the pleasure of having dinner with Brent and Becky Heath, so I’m partial, but there are other very good online bulb nurseries, some of which offer wholesale prices for container gardening on a larger scale.

For design inspiration, search the Internet for “bulbs in containers,” and select “images.”

Do you have a suitable space for container gardening?

Hybridizing Aloes

Hybridizing plants is an easy process: bees do it! They’re usually pollinating plants of the same species, but occasionally, they move a plant’s pollen to a different, compatible species and, without intention, begin the process of natural hybridization.

Human hybridizers, by contrast, have a plan: to improve specific plants. Pursuing this goal requires more than accident. Legendary hybridizer and sometime romantic botanist Luther Burbank said, “The secret of improved plant breeding, apart from scientific knowledge, is love.”

Another important secret, according to contemporary hybridizer, Karen Zimmerman, is fun! She strongly recommends and enjoys hybridizing aloes and growing plants from seed.

Zimmerman is the Succulent Propagator for the Huntington Library, Art Galleries andBotanical Gardens, in San Marino, California. The Huntington’s Desert Garden is one of the largest and oldest assemblages of cacti and other succulents in the world, so her work includes a generous measure of fun.

Speaking to the Monterey Bay Area Cactus & Succulent Society, Zimmerman focused on hybridizing aloes, a genus of succulent plants that includes some 450 species.These include the common Aloe vera, which has a variety of medicinal uses, including soothing sunburns, but a wide range of other forms exist within the genus.

As a hybridizer, Zimmerman studies the several kinds of aloes and explores the potentials of combining features of different kinds to produce hybrids with desirable characteristics. She described several categories of aloes:

  • Size & Form: miniatures, shrubs, trees, and creepers
  • Unusual Leaf Arrangements: fan, spiral rosette
  • Teeth, Prickles, “Warts” or Bumps
  • Colors: white, green, red, black, various patterns

She recognized several prominent hybridizers of aloes, including Kelly Griffin ofAltman Plants, and Brian Kemble of The Ruth Bancroft Garden & Nursery. Hybridizing can build upon the products of other hybridizers, or work primarily with natural species. Hybridizers typically welcome efforts to add to their successes by crossing their hybrids with other plants. This approach is not so much plagiarism as respect. 

Generally, hybridizing can seek improvements in plants for landscape appeal, flowering, vigor, pest or disease resistance, or other characteristics. Zimmerman emphasizes what she terms “fantasy aloes,” which have unusual colors, patterns, or spinose teeth on the leaf margins. She has introduced several hybrid aloes with names that suggest fantasies, e.g.,  ‘Dragon’,‘Gargoyle’, ‘Wily Coyote’, and ‘Chameleon’.

Aloe ‘DZ’ a hybrid by Karen Zimmerman

The process begins with transferring pollen from one plant to another. Zimmerman uses various tools for this task, and currently favors her fingers, tweezers, and dentistry tools.

The nextstep is to collect the resultant seeds, which are small and easily lost.Zimmerman recommends mesh drawstring gift bags, which are inexpensive and effective in catching seeds.

She plants the seeds with labels indicating the “pollen parent” and “seed parent,” plus date and other information of interest. Her planting mix is 80% pumice and 20%forest humus, with the seeds covered with grit. The seeds need to be kept in warm, moist conditions, which can be provided with a closed plastic bag in indirect light.

Aloes, which are monocots, germinate and produce one leaf from the seed in about two weeks. As the plants develop, the hybridizing process consists of editing: the cross between two plants produces numerous seedlings, some of which hopefully will exhibit the desirable traits the hybridizer intended, and others (perhaps all!)will be—as Zimmerman describes them— less interesting, boring, or even ugly.

The seedlings will take various amounts of time to show their mature form. Zimmerman compares them to human teenagers, who reveal their “true selves” at various ages. Some very young seedlings will be unique in interesting ways, while others might be late bloomers.

Editing the seedlings can be the hybridizer’s most important function. It involves choosing those that are worthy of continued development and those that are discarded to make room on the nursery bench.

The hybridizer thinks of appropriate names for the successes and eventually introduces them to commercial distribution. That process uses tissue culture(cloning) to propagate enough cultivars to meet market demand. Seed propagation doesn’t work because growing hybrids from seed yields unpredictable results.

Throughout her talk, “Aloes on My Mind,” Zimmerman demonstrated her continuing enthusiasm for hybridizing aloes, and revealed that, “The real fun is imaging what’s next!”

The succulent gardeners in her audience recognized that hybridizing plants is easy and an enjoyable aspect of gardening that they might just try themselves. One of them could produce next season’s most exciting hybrid aloe.

Planning a Cutting Garden

An ornamental garden, as contrasted with an edible garden, often will yield a number of blossoms suitable for occasional floral arrangements. To produce blossoms specifically for indoor display, however, the gardener needs to develop and maintain a cutting garden.

A cutting garden can be as small or as large as the gardener chooses. Because it serves as a “blossom factory,” it need not be a landscaping feature. It could be a rectangular space with plants in orderly and efficient rows. The bed could be as short or long as desired, but should be no more than about four feet wide, with access on both sides for cultivation, maintenance and harvesting.

The bed should follow the familiar basic standards: fertile soil with good drainage, six-to-eight hours of sunlight, and convenient access to irrigation.

A grouping of Dahlia ‘Jomanda’. Image courtesy of the Monterey Bay Dahlia Society

Plant selection should reflect the gardener’s preferences, which might be based on personal favorites, intended combinations of blossom colors, or other criteria. Unless the gardener has particular plants in mind, the initial plant selection might be based on expert recommendations.

The best source I know for such recommendations is Debra Prinzing, advocate for American-grown flowers, author of The 50 Mile Bouquet and Four Seasons of Locally Grown Bouquets from the Garden, Meadow and Farm. Here are her current top ten picks for summer bouquets:

  • Dahlia — medium-sized forms
  • Zinnia — Queen series for soft colors; Persian Carpet varieties for textural accents
  • Sunflower—‘Plum’, ‘White Night’, ‘Moulin Rouge’, ‘Strawberry Blonde’, ‘Chocolate’
  • Cosmos—Double Click and Cupcake series
  • Ammi—(called false Queen Anne’s Lace) ‘Dara’, ‘White Dill’, and ‘Green Mist’
  • Yarrow—both pure colors and muted/pastel varieties
  • Shasta Daisy—especially double forms like ‘Crazy Daisy’ and ‘Sante’
  • Roses —try some in the caramel and terra cotta range: ‘Hot Cocoa’, ‘Cinco de Mayo’, ‘Pumpkin Patch
  • Herbs— purple basil and ‘Berggarten’ sage for foliage and fragrance
  • Nigella—blue blooms, unusual seedpods, and lacy greenery are eye-catching

After the gardener has selected plants for the cutting garden, the options are to buy and install small plants at a garden center, or plant seeds. Buying small plants involves paying someone for starting the plants from seed, so it’s faster and more expensive than growing your own. But choices could be limited Planting seeds requires less expense, and also provides access to a wide range of options.

Seeds should be planted at the right time of the season. Some seeds should be started indoors in early spring; others are best planted in the ground in early spring, early summer, or mid-summer/early fall. This month is still a good time to start certain seeds for a cutting garden.

An excellent source of recommendations for seasonal planting of seeds for flowering plants is local expert Renee Shepherd. For a timely list of flowers to plant now, browse to her website, click on “Gardening Resources” and search “Time to plant Renee’s Garden Seeds.” Her seeds are among those on display in garden centers.

Seed packets typically have brief instructions for successful planting of seeds.

Flowering plants that have multiple, branching stems will produce maximum yield of good quality flowers with long stems when their primary stems are cut back (“pinched”) at an early stage of growth. Examples include carnation, cosmos, dahlia, and snapdragon.

Pinching is not appropriate for plants that produce just one flower per plant. Examples of such plants include flax, stock, and single-stemmed sunflowers.

Growing your own flowers for bouquets and floral arrangements is one of the most satisfying garden activities. A good time to start your own unique cutting garden, and beginning to gain experience and enjoy the process,  is mid summer/early fall. That’s right now!

Landscaping for Historical Homes

The MontereyBay area was settled in the 1800s; incorporation of Santa Cruz was in 1866, andMonterey in 1889. The area has a good number of older houses, and some current owners of those earlier residences might wish to create a garden that reflects their home’s historical landscape.

A landscaping friend recently began work with a client who lives in a residence built in 1895, and wants to create a garden typical of that era. My friend would like to identify plants that were in home gardens at that time.

A gardening nerd could not ignore such a challenge!

I search the Internet for lists of plants that were in residential gardens of the Monterey Bay area in 1895 (or around that time), and discovered that homeowners did not share lists of plants in their gardens.

There were several missions in central California that typically had gardens of edible and ornamental plants, and missions often recorded their activities. They seemed a promising source of information, but my searches yielded no fruit.

By chance, I learned that the University of California Botanical Garden at Berkeley was formally established in 1890 “to form a living collection of the native trees, shrubs, and herbaceous plants of the State of California…” and “within two years the collection numbered 600 species.” Given this garden’s impressive online database of plants, compiling a list of native California plants of the era seemed simple.

I found, however, that the earliest entries in the garden’s database begin with acquisitions in 1900, and very few in the early years of the century. Vanessa Handley, Director of Collections and Research told me that the initial acquisition records were not maintained after the garden was moved in 1925-28 from its original central campus location to its current position in Strawberry Canyon, above the main campus.

I visited the website of the California Garden and Landscape History Society, which pointed me to “the most extensive scholarly treatment of California landscape history,” CaliforniaGardens: Creating a New Eden, by David C. Streatfield (Abbeville Press,1994). That book and others that looked helpful were available in used (but good) condition for quite reasonable prices, so I ordered a few additions to my library.

The first book that arrived is Restoring American Gardens: An Encyclopedia of Heirloom Ornamental Plants, 1640–1940, by Denise Wiles Adams (TimberPress, 2004). This book includes an appendix of plant lists extracted from nursery catalogs, focusing on about 100 of the most popular plants, organized by different regions in different eras. These lists represent an extraordinary research project by Ms. Adams.

Her lists for the Mountain and WesternStates include but of course do not target the Monterey Bay area. They would provide fine guidance for planning a historical garden for specific periods: 1870–1899,1900–1924, and 1925–1940.

The plants listed are mostly recognizable; today’s plants certainly existed 150 years ago. The plants we find in local garden centers or mail-order catalogs, however, are often contemporary cultivars that would have developed many years after early gardeners planted their gardens. Projects to create an accurately historical garden should feature species plants, rather than the latest hybrid introductions.

The next challenge would be to find species plants!

Gardening for the Near Future: Spring Bulbs

This time of the year is again the right time to plan a colorful display of flowers for next spring. If your garden failed to impress last spring, you can lay the groundwork for a more satisfying experience in the spring of 2019.

The early fall is the time to plant spring-blooming bulbs. A good selection of such bulbs will become available around mid-August to early September in local garden centers and from mail-order nurseries. Two categories of bulbs will be in the greatest demand and likely to be snapped up while some gardeners are just beginning to plan. These two categories are (a) the most popular and (b) the more unusual.

For a list of the most popular spring-blooming bulbs, visit the National Gardening Association’s website, garden.org and search for “The Top 50 Most Popular Spring-Blooming Bulbs.“ You will not be surprised to find several varieties of tulips and daffodils at the top of this list.

To learn about the more unusual spring bloomers, visit the website for Brent & Becky’s Bulbs, click on “Media” and open the file “Spring Flowering Bulbs Cultural Instructions.” This downloadable free publication includes both a long list of spring bloomers and detailed instructions for growing these plants, with particular information for the cultivation of tulips and daffodils.

Another good source of information for both popular and unusual spring bulbs, visit McClure & Zimmerman.

My garden includes a good number of daffodils (all the same cultivar) that I enjoy each year, but the more unusual bulbs are most appealing. This year, I am learning about fritillaria, a genus in the lily family, with about 140 species. The most popular is F. imperialis, called “The Crown imperial,” which is native to countries of the eastern Mediterranean region, e.g., Turkey, Iran, and Iraq. The plant grows over three feet tall and is available in several varieties that have blossoms of different colors. It grows best in full sun, in zones 4–7. The Monterey Bay area is in zone 9, so F. imperialis might be a risky choice for growing here.

Fritillaria meleagris, by Farmer Gracy

A better choice for this area would be F. meleagris, called the Checkered Lily, “Snake’s Head Fritillary,” or “Guinea-Hen Flower.” This plant, which is native to Europe, will grow in sun or partial shade, in zones 3–8, so our local zone 9 environments might be “good enough” for this plant. It will reach to only fifteen inches tall, so it’s not as striking as F. imperialis.

Another important group of spring bloomers that the bulb catalogs do not offer is the irises. That must be because irises grow from rhizomes rather than bulbs, and are offered by specialty growers rather than bulb growers.

I call attention to irises because I have a long association with the Monterey Bay Iris Society, which is preparing its annual rhizome sales. The first sale will occur on Saturday, August 4th at the Deer Park Shopping Center in Rio del Mar. The second sale will be on Saturday, August 11th at the Aptos Farmer’s Market, at Cabrillo College, Aptos. These sales are excellent opportunities to acquire iris rhizomes at good prices and to receive good advice from local enthusiastic gardeners.

If you already have irises in your garden, they should be dug and divided every three or four years for maximum blooms. I call attention to this task because my own irises are overdue for dividing!

Whether you prefer popular or uncommon spring bloomers, preparing for a delightful spring garden happens during the next few weeks. To begin, identify space in your garden where you could plant spring-blooming bulbs, then acquire the bulbs (or rhizomes) of your preference at local garden centers, mail order nurseries, or the local sale of iris rhizomes.

Repotting a Container Plant

At a recent talk by a skillful gardener, I learned new techniques for repotting plants in containers.

First, let’s review the usual approach to this routine process.

When a plant has outgrown its container, the goal for repotting is to encourage and support the plant’s further growth.

The signs that a plant has outgrown its containers include roots growing out of the drainage hole, or roots filling the container (observed after lifting the pant from its container), or an abundance of multiple shoots or offsets. Additional signs of a pot-bound plan: a plastic nursery pot might bulge with the plant’s roots, or the soil in the container dries out quickly.

When the gardener observes the beginnings of such signs, it is time to remove the plant from its container and replant it in a larger container with fresh potting soil and irrigate to settle the soil around the roots. The common wisdom is to move the plant into the next larger container, e.g., from a one-gallon pot to a one-and-one-half gallon pot.

When a plant becomes significantly root-bound, however, good practice calls for root pruning. If roots have been circling the pot, cut through the roots with a hand pruner, and in some cases, peel away the outer layer of roots. If the roots are packed tightly in the pot, loosen the roots, cut away up to one-third of the roots, and make vertical cuts about one-third of the way up from the bottom of the root ball. These actions will stimulate the growth of new roots.

When reducing the root ball in this way, it could be appropriate to replant the plant in the same pot it had outgrown. This might be desirable when the gardener favors the container, or the container complements the plant nicely.

During this process, cut back a proportionate amount of the top growth to reduce the plant’s demand on its reduced root structure. In a short time, the plant will recover from repotting and resume vigorous growth.

Briefly, these are the usual steps to take to rescue a root bound plant and help to continue growing.

Then, Keith Taylor’s eye-opening talk and demonstration for the Monterey Bay Area Cactus & Succulent Society introduced different goals and techniques for repotting plants.

Medusa Plant by Keith Taylor

Taylor has been growing cacti and succulents for about twenty-seven years, with a previous background in bonsai cultivation. He has developed bonsai-related techniques for cultivating succulents, with an emphasis on caudiciform plants. Those are plants that develop a swollen trunk, stem or root—called a caudex—that stores moisture. These unusual plants are candidates for bonsai treatment and often favored by collectors.

(Note: The specimen shown here is a Euphorbia, which is not a caudiciform.)

Instead of repotting plants to encourage and accommodate growth, Taylor seeks to limit their size, promote larger and wider caudices, and stimulate compact top growth.

In pursuit of these goals, Taylor’s distinctive approach to repotting includes severe pruning of the plant’s roots and top growth. Without hesitation, he would cut off a plant’s taproot and close to all its fibrous roots to reduce the root ball to fit into a shallow bonsai pot. With some caudiciforms, he would cut the caudex literally in half, and wait for it to develop new roots.

Top growth pruning was equally extensive with the same objective of constraining the plant’s overall growth.

The roomful of avid gardeners of cacti and succulents understood Taylor’s bonsai pruning method, although this approach to gardening was unfamiliar them. These gardeners were familiar with limiting the size of their plants by keeping them in small containers with lean soil mixes and minimal moisture.

At the same time, many were astonished by Taylor’s relatively extreme pruning practices, which freely exceed the usual guideline to remove no more than one-third of a plant’s roots or top growth. While Taylor admitted that some of his early trials of such pruning were unsuccessful, he has found that many plants tolerate this treatment and respond well in time.

The gardeners in attendance learned that the one-third rule for pruning could be overly conservative and that more severe pruning could be effective in limiting plant growth. Bonsai-style pruning of cacti and succulents remains as a specialized form of container gardening and not everyone’s preference we learned that extreme pruning does not necessarily kill a plant.

Taylor’s distinctive pruning practices are closely related to his work in creating containers for plants. Examples of his extraordinary ceramic pots can be viewed on his website,  and his Facebook page, where he is known as “Kitoi” (his childhood nickname).

Even when we know basic gardening methods, new knowledge is always ready for discovery.