Social Distance XIV – Self-Spreaders

We continue our exploration of ways to pursue  gardening while maintaining social distance.

Care for Your Garden

Last week’s column listed some basic landscaping concepts, one of which is “Plant in Groups.” As an expansion of that concept, we explore landscape uses of self-spreaders: plants that propagate by generating lots of seeds and plants that propagate by creating roots, stolens, bulbs, corms, or rhizomes. We could call these groups self-seeders and runners.

When we adopt the objective of planting in groups, we can regard the self-spreaders as botanical partners in landscaping. While it is quickest to develop plant groups by purchasing and planting multiple specimens of a selected plant, collaborating with these partners can require a few seasons of growth, but is considerably less expensive.

To begin planning for self-spreaders, acknowledge that they can appear in one of three broad categories: garden-worthy plants, thugs, and weeds. These categories are not botanically distinct. Instead, their membership in one category or another depends on their circumstances and the gardeners’ priorities. The landscape planner should be prepared to recognize which category to which an unexpected seedling belongs.

Many weeds propagate quickly, using either seeds or runners for the purpose. The most notorious in my garden include Bermuda grass ( Cynodon dactylon), which is a popular for lawns in southern United states, and Bermuda Buttercup (Oxalis pes-caprae), which has no friends that I have encountered. Both are South African natives, and both might have been introduced to the United States through Bermuda.

There are countless other self-spreading weeds.

Gardeners can learn to recognizing weedy problem plants best through experience. It is not always important to know their common or botanical names, only to know them when you spot them. The best control is hand-pulling by their roots; effective inorganic approaches exist for both annual and perennial weeds, with each group needing seasonal control schedules.

At the other extreme of self-spreading plants are the garden thugs. These are plants that have appealing qualities, but that spread more vigorously and persistently than gardeners usually want. This is another large category. Examples from my direct experience include Bears’ Breeches (Ancanthus mollis), Spiny Bears’ Breeches (A. spinosus), California Wild Rose (Rosa californicus), Japanese Anemone (Anemone hupehensis and other species), and English and Algerian Ivy (Hedera species). With hesitation, I include the California Poppy (Eschscholzia californica) because it pops up in unexpected spots presents cheerful blossoms, and then evolves to a mess. This is our state flower, but I would rather it would grow elsewhere.

Acanthus Blossom
Acanthus spinosus grows aggressively in the garden

Finally, we get to the garden-worthy. self-spreading plants. These self-spreaders can be genuine assets to the landscape, and still their propagation can be managed seasonally without great effort.

The strategies for working with these botanical  partners include first allowing them to go to seed. If you deadhead, you get more blooms; if you don’t deadhead, your get more plants.

A second practical strategy is to manage the spread of these plants in the spring by removing misplaced progeny or transplanting them with care to a preferred location. Plants that propagate from runners can be moved quite successfully when the transplant includes a substantial amount of root. 

Happily, a large number of plants fit in this category. Examples from my direct experience include the following:

Winter Blooming Bergenia or Pigsqueak (Bergenia crassifolia).This plant was given to me about twenty-five years ago and has spread courteously in my garden. I have recently given away more than 100 gallon-size plants without creating a gap in my landscape.

Cranesbill/Hardy Geranium (Geranium x cantabrigiense). I installed this plant several years ago as a low-growing border. It has since spread slowly and methodically to create a  blanket about eight feet wide. It is an attractive plant, but one that must be reduction to share through the garden exchange or compost.

Four O’clock (Mirabilis jalapa). I started this plant two years ago from seeds shared by a friend and from selected seeds from Rene’s Garden. It  has been a reliable perennial that produces good flowers that bloom late in the day, dies to the ground, and returns vigorously in the spring. The seedlings are easily controlled to manage its spread.

Advance Your Gardening Knowledge

All plants propagate themselves one way or another, and many are garden-worthy selections or weeds or garden thugs. There are far too many to list here, advance you familiarity with each of these categories, make systematic observations in your garden, search your local library or bookstore of online book seller, or search the interne for “self-seeders” or “plant runners.”

Enrich Your Gardening Days

As you work patiently with your garden’s botanical partners, you will gain considerable satisfaction in developing your landscape in a well-managed and very inexpensive manner. This easy process is at the core of real gardening nature.

Keep your emotions positive and your viruses negative and enjoy your garden.

Renovation of the South African Garden

I recently visited UC Santa Cruz’s Arboretum & Botanic Garden for a preview of plans to renovate the Arboretum’s South African Garden. Executive Director Martin Quigley and Nursery Manager Martin Grantham presented these plans to a small group of interested supporters of the project.

The South African Garden holds the Arboretum’s impressive collection of plants from the Cape Floristic Region, the smallest of the six recognized floral kingdoms of the world, is an area of extraordinarily high diversity and endemism. The Arboretum’s other major gardens focus on California, Australia, and New Zealand.

Among the South African Garden’s extraordinary Leucodendrons, Leucospermums, and Proteas, several other native plants also deserve a gardener’s attention. One example is the Bush Aster (Felicia amelloides), which offers striking sky-blue and sunny yellow flowerheads, held well above the leaves.

Purple Blossoms
Bush Aster (Felicia amelloides )

Interested persons can see examples of the Arboretum’s South African collection by visiting the Arboretum’s website and searching for “South Africa.” 

The South African Garden was established early in the Arboretum’s history, which dates from 1964. Its development continued over several decades, but slowed markedly after the retirement of Ron Arruda, then the curator of the South African Collection. Due to budgetary limitations, a new curator could not be hired, so other staff provided minimal maintenance and development.

The arrival of Martin Quigley, three years ago, and Martin Grantham, last fall, brought a combination of vision and expertise to the South African Garden. Quigley brought a strong background in botany, horticulture, landscape architecture, plant ecology, and related fields. Grantham, a new addition to the staff, but about nine years ago he produced impressive “observations and ideas” for the South African Collection. Together, they soon generated an imaginative plan for renovation of the South African Garden.

Over the years, the South African Garden had developed a remarkable collection, but the typical visitor could easily feel confused by its arrangement of unfamiliar plants. While there might be a horticultural rationale to the grouping of plants, each plant seemed unrelated to its surroundings.

One notable exception has been the grouping of several species of Cape Heaths (the large genus Erica), comprising perhaps the largest collection of these plants outside South Africa. The Erica collection provides a valuable opportunity to compare diverse species and enjoy their flowering in late winter/early spring and mid-summer.

The renovation plan for the South African Garden envisions several focal displays. Visitors can anticipate these unique presentations:

Silver Tree Grove. These small trees (Leucadendron argenteum) are relatively short-lived, but their silvery, silky leaves provide a memorable effect. A gathering of these trees will be quite charming,

Pelargonium Field. Gardeners often have been confused by the relationship of geraniums and pelargoniums. There are historical reasons for the confusion, but today’s taxonomists tell us that these are different genera within the family Geraniaceae. Here’s a short explanation from “Geraniums are herbaceous perennials of the Northern hemisphere that can be also found in Africa and South America. Pelargoniums, on the other hand, are subshrubs from the southern hemisphere and occur naturally almost entirely within South Africa.” The Arboretum’s plan includes the creation of a Pelargonium Field that will both help to identify true pelargoniums and suggest the great variety of plants that are native to the Cape Floristic Region. It also will provide a pleasing display of colorful blossoms and attractive foliage.

Restio Maze. One of the exceptional plants of South Africa are the members of the genus Restio, which includes more than 160 species. These are rush-like plants that likely “originated more than 65 million years ago during the Late Cretaceous period, when the southern continents were still part of Gondwana.” This genus includes a great variety of species, as one might expect. The Arboretum’s plan includes the development of a maze comprised of several different Restios, designed to showcase the variations within the genus and offer visitors an opportunity to commune with these dramatic plants. A maze and a labyrinth differ in important ways. By some accounts, a maze presents a challenging puzzle, while a labyrinth offers tranquility. We will have to discover the Arboretum’s Restio Maze when it ready for visitors. Today, it consists of plowed circles defining a coming attraction that is fifty-feet in diameter, with ten-foot wide pathways. Fortunately, Restios grow relatively fast, so it won’t be very long before we could explore this maze. It surely will be the first of its kind!

This plan for renovation of the Arboretum’s South African Garden is still evolving, so expect to see additional features in the coming months. The Arboretum has a long history as a horticultural treasure for the Monterey Bay area and California, and this new arc of development will increase its value.

Meanwhile, the South African Garden continues to invite a casual stroll on a pleasant day, and a resource for broadening one’s horticultural experience. The Garden’s plants all grow well in the Monterey Bay area, and a selection is available for purchase at the Arboretum’s garden store.

Filling a Hole in the Landscape

Garden projects sometimes begin with a routine, manageable task that grows into a challenging project. That was a scenario on a recent occasion when I had gardening help for seasonal pruning of two large plants that had finished blooming. The day’s targets were two winter-blooming Mexican plants: the twenty-foot Tree Dahlia (Daisy imperialis) and the twelve-foot Daisy Tree (Montanao grandiflora). I wrote about these favored plants recently, and did not mention that they should be cut to the ground after blooms had faded to promote their amazing new growth during the following summer.

This pruning requires whacking and hauling, rather than horticultural precision, so it went quickly. With clippers, loppers and saws already in hand, we turned to other pruning needs in my garden’s California native plant landscape. There were several overgrown plants that needed attention, but the prime candidate was an American Black Elderberry (Sambucus Canadensis). It is native to the eastern United States (not California), but it was a volunteer in the landscape and did not belong in my California native garden. It was healthy, but had grown rather quickly into a twenty-foot specimen.  It was under an enormous Lemonwood (Pittosporum eugenioides) and had become rangy due to lack of exposure to sunlight. (The Lemonwood, a native of New Zealand, also does not belong in my California native garden but it’s far too big to push around.)

We began pruning the Elderberry, trying for a more attractive form, but quickly concluded that it had to go. After all, there was still space in the truck, atop the branches of the Tree Dahlia and the Tree Daisy.

We soon reduced the Elderberry to a stump, which we left to be dug out on another day.

The session that began with routine pruning resulted in a significant hole in the landscape that presented an opportunity to install something new, interesting, and native to California. The site is about ten by ten feet, defined by the northwest property line, the Lemonwood, and a picket fence that separates the California and Mediterranean Basin gardens. The adjacent residence, which is close to the property line, shades this site, and the Lemonwood blocks most of the overhead light.

The first challenge was to identify a California native plant that would enhance the garden, grow to an appropriate size, and thrive in this shady environment. The second step would be to find a source for the selected plant.

Roaming through local garden centers would not be an efficient strategy for such a search, so we went right away to garden books and the Internet. Here are the initial findings, as a demonstration of this search.

Sunset Western Garden Book

  • Coast Rhododendron (Rhododendron macrophylla): Grows 4–10 feet tall. Partial shade. Modest ratings for flower quality, plant appearance and garden performance.
  • Western Azalea (Rhododendron occidentale): Grows 6–10 feet tall. Partial shade. “Superior named cutting-grown plants are scarce but available and worth looking for.”
  • Teaberry (Gaultheria shallon): Grows 4–10 feet tall. “Loose, 6-in.-long clusters of white or pinkish flowers on reddish stalk bloom in spring. Edible black fruits…follow the blossoms; they’re bland flavored, but birds like them.”
  • Evergreen Huckleberry (Vaccinium ovatum): Grows to 9–10 feet tall and broad in shade. “Leathery, lustrous dark green leaves to 1-1/4 in. long; bronzy or reddish when new. White or pinkish flowers are followed by black berries good in pies, jams. jellies, syrups. Cut branches are popular for arrangements.”
Evergreen Huckleberry (Vaccinium ovatum) grows 9 to 10 feet tall and broad in the shade.
Photo by Tom Hilton, via Wikimedia Commons
Evergreen Huckleberry Leaves
Leaves, Evergreen Huckleberry (Vaccinium ovatum), Photo by Ben Dody, via Wikimedia Commons

Las Pilitas Nursery, which specializes in California native plants

  • Blackfruit Dogqood (Cornus sessilis): Grows to 15 feet. Part to full shade. “Cornus sessilis’s foliage turns a different color in the fall, color is silver and type is deciduous. Cornus sessilis’s flower color is white.” “It looks like a woodland plant.”
  • Red Stem Dogwood (Cornus stolonifera): “…elegant open shrub with creamy white flower clusters in spring and red stems. It can be found in moist areas, in sun or shade…has green foliage and is deciduous in winter, exposing its attractive red bark. This dogwood is a must for winter interest in the garden, is lovely in the spring when the plant is covered with clusters of creamy flowers…”

California Native Plant Society—Calscape website

  • Creek Dogwood (Cornus sericea): Grows to 13 feet tall and15 feet wide. “In the wild, it commonly grows in areas of damp soil, such as wetlands.“ “spreading readily by underground stolons to form dense thickets.”
  • Cream Bush (Holodiscus discolor): “It is a fast-growing deciduous shrub growing to 5 meter tall.” “Cascading clusters of white flowers drooping from the branches give the plant its two common names. The flowers have a faint sweet, sugary scent.” Moderate-to-high water requirements.

Most shade-loving California native plants found so far are five feet tall or smaller, and many require moist conditions. Several are quite attractive for the garden. The most attractive option discovered so far is the Evergreen Huckleberry (see photo). In the interest of thoroughness, I will continue searching for an ideal plant for this particular site.

Making Your Garden Climate-friendly

Traditionally, we make our New Year’s Resolutions on New Year’s Eve, or perhaps on the morning after, when we are inspired to change our ways for the better.

From another perspective, we can at any time commit ourselves to self-improvement or even higher goals. This column invites gardeners to create climate-friendly gardens in 2019, as their individual contribution to efforts to combat global warming.

Essentially, global warming results from the imbalances of the normal carbon cycle, which begins when plants capture carbon dioxide (CO2) from the air and convert it into plant tissues.  As the plants are eaten and digested by animals, or die and decompose, CO2 is formed again and returned to the atmosphere. At the same time, vast quantities of carbon have been stored in the ground in the soil and what we have regarded as fossil fuels: oil, coal, and natural gas.

This natural cycle, which has continued for a very long time, has been disrupted as humankind has burned the fossilized materials and released their stored carbon into the atmosphere, disrupting the carbon cycle.

The challenge that humankind now faces is to reduce and eventually eliminate burning of oil, coal, and natural gas, and to produce energy through other means, notably by capturing the suns energy. This is the existential mission, i.e., its purpose is to sustain the existence of human life on the planet.

From the gardening perspective, gardeners can participate in this mission in two ways.

Reducing the Use of Fossil Fuels

This strategy involves reducing the direct and indirect consumption of fossil fuels in the garden. The direct consumption of these fuels involves using gasoline-powered equipment, notably lawn mowers, and other devices, including trimmers, edgers, chain saws, tillers, sod cutters, and the like. While occasional use of such devices might be unavoidable, whenever possible gardeners should use electrically powered devices or, ideally, hand-powered equipment.

For the record, the generation of electricity often involves burning fossil fuels, but the shift to renewable energy production is in progress, and deserves support.

The indirect consumption of fossil fuels occurs when we use synthetic fertilizers and pesticides (insecticides, herbicides, and fungicides), all of which require significant amounts of fossil fuel energy for their manufacture and transport. The clear option is to discontinue uses of these materials and to identify and use organic alternatives.

This transition can require finding sources of organic fertilizers and learning about natural, organic approaches to the control of pests and weeds. If you already know about these options, you are ready to commit to their use.

Capturing Carbon in the Garden

The gardener’s second strategy for combatting global warming is to support the ways that the garden stores (sequesters) carbon. Again, this is a natural process, so it is not difficult to incorporate in the garden. Here are the principal methods:

  1. Keep the Soil Covered. Bare soil releases carbon into the atmosphere, so when areas of your garden are not inactive use, plant cover crops (grasses, cereal grains or legumes) to protect the soil and add nutrients. This approach is particularly relevant for vegetable gardening, which can leave soil bare between crops.
  2. Avoid Tilling the Soil.  Turning the soil with a tiller, garden fork, or shovel might seem be help plants to root, but it also moves dormant weed seeds into growing position, and releases carbon into the air. The roots will do fine on their own!
  3. Plant Trees and Shrubs Densely. A full complement of trees and shrubs helps to draws carbon from the atmosphere, and also provides a natural, attractive landscape. The basic design concept is to emulate the natural environment.
  4. Recycle Organic Matter. Your green bin is still a good place for roots, twigs and branches that decompose slowly, but dead leaves and green clippings should be composted and returned to the soil. But leave weed seeds out of the compost bin.
  5. Grow “Greener” Grass. If you have a lawn area, you might be concerned about its environmental impacts but pleased to know that lawns absorb and store CO2 rather well. Lawns have the potential, however, to emit harmful nitrous oxide, particularly when fertilized and watered generously. The best practice is to select grasses that do not require such treatment, mow the grass at a height of about three inches, and leave the clippings to decompose into the soil.

In addition to helping to save the planet, climate-friendly gardening is compatible with environment-friendly practices, and with your gardening success. It’s still a good time to commit to climate-friendly gardening as your resolution for 2019.

For more information on this topic, see “The Climate-Friendly Gardener: A guide to Combating Climate Warming From the Ground Up. This is a free download from the Union of Concerned Scientists. 

Creating a Garden Map

Creating a record of the plants in your garden yields several benefits. A “garden record” includes two essential components: the name, photo and basic cultivation notes for each plant, and an indication of each plant’s location in the garden.

A more elaborate plant record could include extensive plant info that reflects the gardener’s interests. Examples include purchase details (when, where, cost); native region; and landscaping ideas. The record could be extended further with notes on the plant’s development over time, including bloom times, pruning, propagation, fertilization, etc.

Such details, while relevant, are the territory of professional growers and very zealous gardeners.

The minimalist approach to a garden record involves simply inserting a plant tag in the soil next to the plant. A respectable tag from the nursery provides the plant’s botanical and common names, plus a phrase about its mature size and growth needs. Placing the tag in the soil marks its spot in the garden. This method, although popular, has notable shortcomings: sparse information, ephemeral mark of location, and plastic intrusion into the natural setting.

Plant tags are best used for temporary reference, during the preparation of a better garden record.

After considering those extreme forms, let us return to the fundamental model of the plant record.

Plant Information

Compiling information on an individual plant can be accomplished most easily and quickly with an Internet search, using the plant’s botanical name, or, if necessary, its common name. This information should be available on the plant tag.

The first search should be the website of the nursery that grew the plant. The nursery’s name could be read from the plant tag, or provided by garden center that sold the plant.

Other good sources include San Marcos Growers in Santa Barbara. SMG grows many plants and supplies them to garden centers. Their website (includes a fine database of plants that they grow —or used to grow— with photos and detailed descriptions, cultivation suggestions, and notes on the plant’s discovery or hybridization.

More good online resources include Wikipedia for plant information and Wikimedia Commons for plant photographs.

Other websites with useful plant information could be discovered through a botanical name search.

After locating basic plant information, good practice involves developing a database of plants in your own garden. This could be accomplished on paper or in digital form, i.e., as a computer file. Organize the plant under discrete planting beds or areas of the garden.

Garden Map

The second component of the garden record is a map showing the location of each plant in the database. Plant locations could be documented with notes within the plant description, but a graphical map would be a more useful reference for monitoring plant growth and developing the landscape development.

The garden map need not serve as an artistic triumph or an exercise in precise engineering, but it should amount to a scale drawing of the garden area. For a garden on a standard lot with a typical complement of plants, a map of the entire garden could be sufficient. For larger gardens, or those with many plants, a series of maps representing areas of the garden would support notations indicating plant locations.

On the map, represent each plant with its name, or a numeral linked to the plant record, or a numeral linked to symbol. The symbol could be a circle of appropriate size, or, for the artistically inclined, a simple drawing that suggests the size and form of the plant.

Again, primary purpose of the garden map is to document plant locations, rather than to create a work of art.

The map must be editable, so that it could be updated to reflect additions, deletions, and relocations of plants. Working in pencil could be most appropriate.

A garden map also could be created and maintained as a digital file. This method involves the use of computer graphic software, either a general purpose or garden-mapping application. This column cannot include an overview of garden mapping software, but, generally, the garden-mapping software that is currently available is intended for edible gardens in which plants grow in rows. Such software could be helpful for planning and describing traditional vegetable gardens, but is not suitable for ornamental gardens, or for edible gardens that are designed for aesthetic effect, including those that creatively combine edibles and ornamentals.

Graphic design software with the functionality needed to represent irregularly shaped planting beds is certainly available, but tends to require significant expense and skill.

Avid gardeners can develop plant information and garden maps to create garden records of substantial value in developing and maintaining the garden. Good practice suggests adopting readily accomplished formats, rather than aspiring to high standards that are unlikely to be achieved or maintained. The first priority should be to create the garden record as a practical tool for planning, developing and maintaining your garden.

The rainy season is a good time to pursue your garden record project!

Assessing a Neglected Shrub

A situation that could arise in any garden, including your garden: the gardener becomes aware of a shrub that has been neglected and that has outgrown its space and become rather misshapen. In addition, the gardener has lost track of the shrub’s name and can’t locate cultivation notes on the Internet.

I recently had such a challenge in my garden’s Australian bed. While I was not paying attention, a shrub grew to about five feet high and eight feet wide, and began crowding adjacent plants. In addition, it had been produces leaves and flowers at the ends of its branches, so that the interior of the plant consisted of bare branches. Some of those had died back so that lifeless tips of branches appeared among the greenery.

The plant had been in place for a few years, and I could not recall its name.

For the past several years, when I added a plant to the garden, I searched the Internet for a photo, a verbal description, cultivation notes, and any other information of interest, and compiled it into a one-page “fact sheet” to be added to my files. Such searches begin with the plant’s botanical name, which is almost always listed on the plant’s tag or nursery container.

As a result, I had a binder of such information for the plants in the Australian bed. Despite this preparation, I could not identify this plant.

After staring at my files for Australian plants, I realized that one fact sheet described this particular plant quite well, but the accompanying photo showed red flowers. The plant in question has white flowers!

Apparently, I had included a photo of a different cultivar of the plant. I learned that the red-flowered cultivar is more widely used than the white-flowered species in my garden. (The ‘Snow White’ cultivar has double, green-centered blooms, but my plant has single white blooms with unremarkable centers.)

I replaced the photo, and was satisfied that the plant is a Tea Tree or Manuka (Leptospermum scoparium), a member of the Myrtle plant family (Myrtaceae) and a native of Australia and New Zealand. The generic name means slender seeds, and the specific name means broom-like.

Tea Tree or Manuka (Leptospermum scoparium)

I then learned that this plant has several desirable characteristics. It is drought-tolerant, fairly slow-growing, appealing to bees and not appealing to deer. It has fragrant, evergreen foliage and a profusion of small flowers that appear in the late spring and summer, and linger into the fall. Its leaves can be brewed into a fine tea and Manuka honey produced by bees from its flowers has medicinal properties.

On the downside, at maturity this plant can reach ten feet tall and wide, making it too large for my Australian bed.

I considered pruning this shrub to manage its size. My Internet research found advice that the Tea Tree could be pruned after flowering to maintain shape and encourage bushier, more floriferous growth. However, pruning should never cut into bare wood “as new growth is unlikely to sprout.”

This reflects the pruning advice for plants that also flower on the previous year’s growth, including Camellias, Rhododendrons, Lavenders, and several others. This is critical information, because hard pruning of the Tea Tree would leave it looking and performing essentially dead.

While a light pruning after pruning would stimulate next spring’s growth at the ends of branches, there is no opportunity to reduce and maintain this sprawling plant to a more compatible size. If had been grown as a hedge or as a backdrop for the garden, it could have had long-term value in the landscape. In its current stage of growth and its present location, however, it will be an increasing problem.

This assessment of a particular plant recalls a basic guideline for landscape planning: always know a plant’s size at maturity before buying and placing it in the garden.

Great satisfaction can result from a well-placed plant. Conversely, removing a healthy plant leads to regret. From a positive perspective, removing the Tea Tree will eliminate conflict with nearby plants and free space for smaller Australian native plants.

Anticipating Change in the Garden

We can experience the garden as an instance in the flow of time, beginning in the past, through the present, and into the future.

Except for rare occasions, we give little thought to the garden’s past. We might take pride in the improvements over the wasteland (or mess) it once was, but usually we focus on the present.

We enjoy the plants that show good health and colorful blossoms.

In my garden, for example, I am currently appreciating an irregular row of Madeira Germanders (Teucrium betonicum) that are growing to screen the view to and from my neighbors. These evergreen shrubs began as divisions of and cuttings from an established plant, and are growing to about six feet high and five feet wide with attractive inflorescences of fragrant, violet-rose flowers.

Madeira Germanders (Teucrium betonicum)

Several other plants are still in flower at this time, but as the season winds down, many blossoms are beginning to fade, and some have already shriveled. At this time of the year, the present includes the late stages of seasonal blossoms and the anticipation of their natural demise.

Our attention shifts now to the anticipation of the garden’s future, which unfolds in a series of stages.

The first stage embraces the emergence of the fall-blooming plants; here are three examples from my garden.

Tree Dahlia (Dahlia imperialis). This amazing plant from Mexico sends up twenty-foot high stalks and blooms in November with sprays of light lavender-pink flowers high above the ground. These are single blossoms, unlike the multiple forms of hybrid dahlias. After bloom, we cut the stalks to the ground and begin the cycle over again.  

Daisy Tree (Montanoa Grandiflora). Another dramatic plant from Central America, the Daisy Tree grows from its base to produce multiple branches up to twelve feet tall. In November and December it produces an abundance of white, daisy-like flowers with yellow centers and a fragrance reminiscent of chocolate or vanilla. It is cut back hard in early spring to encourage the development of new branches form the base.

Black Mission Fig (Ficus carica).  One of the most popular varieties of the common fig, Black Mission was introduced in the United States in 1768 and Franciscan missionaries planted it in all the gardens of the California missions. This plant produces two good crops each year: the first or breba crop develops in the spring on last year’s shoot growth. The main crop develops on the current year’s shoot growth and ripens in the late summer or fall. My tree is bouncing back nicely after last year’s extensive pruning. Its first crop was sparse, but now its main crop is developing now and looks to be quite productive. I might drape bird netting over the tree to enable the harvest of figs for eating and gifting.

The next stage of anticipating the garden’s future targets the spring bloom. This is when we see irises, daffodils, other spring geophytes, and annual flowers coming into their own, assuming of course that we planted them in the fall.

The spring is also the time when fall-planted perennial plants leaf out, after developing their root systems during the winter months, drawing upon the seasonal rains.

Our stages of anticipation then address the gradual development of young plants that we had installed in our gardens. Each year’s growth advances these plants toward their mature size, and the realization of the goals we had when bringing small plants to the garden. There is great joy—and little effort—in watching plants achieve their potential.

The last stage of anticipation begins with the gardener’s vision of what the garden could be, and could sustain for a very long time. The vision can only become real when the gardener puts hands in the soil.

It can be satisfying to enjoy your garden in the present, but the joy of gardening also resides in these stages of anticipation. Gardens evolve continuously, and gardening includes engaging with nature’s processes.

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.

Landscaping Priorities

This year’s Fall Equinox lands on September 22, marking the unofficial start of the planting season.

Installing new plants in your garden during the fall provides them time to establish roots and prepare for leafing out and blooming in the spring. Ideally, we would have our historic pattern of winter rains during this time, so that the plants will have ample moisture to work with.

An additional benefit of this planting schedule might include end-of-season plant clearance sales at your favored garden center or nursery. You can feel like a savvy garden shopper when you acquire plants at good prices in the fall, and resist the temptation to stock up in the spring, when small plants have been forced into seductive blooms with nitrogen fertilizers.

The planting season is still a couple weeks away, so right now is a good time for planning to select and install plants in your garden. Having a plan when you open a mail order catalog or walk into a garden center will prepare you to focus your targets and avoid becoming overwhelmed by the array of possibilities.

Strategies for garden planning in the Monterey Bay area include emphasizing drought-tolerant plants, or California native plants, or a particular theme of your own choosing. Earlier versions of this column have addressed such strategies.

Today’s column describes additional strategies suggested by Rochelle Greayer, author of Cultivating Garden Style (Timber Press, 2014). In her online newsletter, Pith + Vigor, Greayer recently identified three mistakes that gardeners make when designing with plants:

  • Too many different plants
  • Not enough plants
  • Planting just the plans you know.

Let’s consider positive strategies in these three areas.

First, develop your landscape around a just nine to twelve different plants. Selecting plants in this short list for specific roles will bring order and cohesion to the landscape, and avoid the chaos that too often results from impulsive additions of individual plants.

Second, once you have selected your short list of plants, install lots of them. This strategy is related to adding plants in clusters of three, five, or any other odd-numbered quantity, to present them in a natural and pleasing manner. As you reach larger numbers, install the plants in swathes or bands to provide a landscaping effect. Greayer says, “Repetition gives a scheme flow and rhythm. Repetition is a savvy designer’s best trick.” For example, I recently planted two parallel arcs of blue and yellow irises as a color statement for next spring. Over the next few seasons, these plants will increase to provide increasingly dramatic displays.

A swath of Dalmation Iris (Iris pallida ‘Variegata’) backed up with Lavender plants
A bed of hardy geraniums (Geranium × cantabrigiense ‘Biokovo’ ) with a garden art pheasant

Related to the idea of repetition planting is the installation of plants with close spacing. While you might be tempted to spread plants out to cover space in the garden, having open areas between plants reduces their visual impact and invites the growth of weeds. Close spacing reflects the natural tendency of plants to propagate and develop into colonies. It also functions as “green mulch,” denying weeds the sunlight they need to develop.

Third, explore the wonderful world of plants to find good choices for your short list of selections for the landscape. It’s always important to select plants that are suitable for the climate, soil and exposure of the locations for which you are planning, but there are always many interesting selections that are both suitable for your garden and new to your experience. Relying on common and familiar plants will doom your landscape to being (gasp!) ordinary. Discover interesting plants that will bring excitement to your garden, and invest time in learning how to cultivate them successfully.

In review, there are three strategies for planning the development of your garden during this planting season: 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 and provide a fresh new look to your landscape.

Enjoy this fall’s planting season, and your garden’s coming spring!

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!