Foliage Color and "Harmony" in Landscaping and Good Taste in Building, etc.

The typical California cityscape (or better, suburb-scape) is an offense to the eye, a nerve-jangling hodgepodge of incongruous shapes and colors and textures, the result of thousands of individual homeowners picking at random from a way-too-broad “palette” of trees than can be grown here.  The result is a scrambling of the flora of the world in a way that is natural to nowhere in the world and looks unnatural anywhere in the world, and is to be found everywhere in our part of the world.  The overall effect is as repulsive as it is ubiquitous.

Let us imagine a scene in January in any suburb in California.  A tall palm tree here (for a tropical note), a leafless deciduous tree there (a reminder of the East), a redwood here (a touch of the North Coast), a big eucalyptus tree, a yellow-green cary?? tree next to a livid purple-red liquidambar, which should be leafless but isn’t, an Australian acacia, just bursting into its “spring” flower display, spires and lollipops, clashing livid colors, plants showing signs of every season of the year and coming from every part of the world and almost every kind of climate, all vying for attention, a bedlam of individuals . . . bananas and lilacs, tulips and cacti.  Nobody would tolerate such raucous discord if it were music, or food (pureed steak with ice cream topping), or almost anything but gardening.  Perfectly good ingredients but hideously combined.  The food analogy might be understandable by almost anybody—after all, isn’t that where we got the idea of “good taste” from?

The diametric opposite to this chaotic suburban landscape can be found in almost any part of the world that still has its natural vegetation.  No matter what kind of vegetation it is, from desert to tropics to grassland or marsh or woodland or high mountain, it is always in absolutely perfect taste.  Its component species, no matter how few and similar or how many and dissimilar they may be, are always arranged in absolute harmony, everything in the most perfect possible place to achieve the most soothing, delightful effect possible.  And this is true whether the scene is viewed from high above or in the most intimate close detail.  I have never seen a garden or landscape designed by even the most talented human that could equal the most humble natural landscape.

All this aside, though, we are talking here about gardens and landscapes that are designed by people, and although never as perfect as in “real”, i.e. natural landscapes, there are plenty of examples where people hae created not only gardens, but villages, towns, even cities that are almost as restful-looking and pleasing to the eye as any scene of pure nature, and even more appealing in terms of looking inviting.

Here, too, such towns look equally good from above or from close up, fitting into the larger landscape as harmoniously as any natural part of the scenery, looking as if they grew up organically out of their surroundings—which, invariably they did.  I refer of course to what are condescendingly referred to as “primitive”, “old-fashioned”, or “quaint” sorts of human habitations, such as you might still find in remote parts of Africa and Asia, but equally in more affluent parts of the world, especially Southern and Western Europe, and more rarely, even in a few places in North America.  The common denominator is that these tasteful, inviting-looking habitations and towns are old, or at least “traditional”.  They are compact, not sprawling, and they have a unifying style or building material (the material is always best if local, especially in the case of stone, which gives a real organic look to a town) even though the particular design is not necessarily monotonous; in fact the best have no end of variations on the theme.  The main thing is, there has to be a theme.  And it matters little what the theme is—Tudor half-timber and thatch, Cotswold stone, adobe, whitewashed stucco with red tile roofs. . . .

Only the fairly recent, first-world developments both in architecture and urban design and in garden and landscape design have introduced the cheap, tawdry ugliness we now take for granted.

And just as the “traditional” style of buildings and town design look harmonious and “comfortable” in their surroundings, so too do “traditional” kinds of gardening and horticulture.  Go to any village in England and you will see only trees and shrubs etc. that look right together and combine to form an overall harmonious big picture.

In this case the trees are nearly all deciduous, with a more-or-less rounded form, set in a landscape kept green by all-year rains.  This is the exact opposite of the typical California cityscape, which seems unable to decide whether it wants to look like Australia or England or Greece or some unspecified tropical island.  In England—and throughout Northern Europe—the gardens and the overall landscape looks like . . . Northern Europe.  In other words, it fits [I could easily launch into the “grow natives” issue here, but let’s hold off for now].

Such a simple thing as color is a big part of it.  Clashing colors (in addition to clashing shapes etc.) is a big part of what makes the typical California suburb jangle the senses so badly, and the lack of same is a big part of what makes any natural landscape (and man-made landscapes in less climatically favored places as England) look so harmonious.  California’s ideal climate is its horticultural two-edged sword: you can grow almost anything—and that is the trouble with it as well as the advantage of it. 

Let’s briefly go over some of the color aspects of various parts of the world, and while we’re at it, the other main visual factors as well—shape and “texture”.  All this will apply mainly to the trees, since they are responsible for the big, overall visual effects and can either make or break the scene.

Each of the following major categories has a characteristic gestalt to its vegetation that makes it recognizable at a glance.  Any garden, or major portion of a garden (or larger landscape like a city park, golf course, or cemetery) could do no better than to stick faithfully to one or another of these regional “themes” and, regardless of what particular country the plants come from—so long as they come from the same kind of climate—they are likely to harmonize well and at least look like a “natural” landscape, the highest compliment a garden can have.  Of course it would be really ideal for a whole town or, more realistically, a housing tract to stick with variations on a single theme, the way Santa Barbara has stuck with a single architectural theme, to the great benefit of all.  The following categories are practical and ecological rather than geographical.  They are:  montane and alpine (Eastern and Western Hemisphere), desert, pantropical, north temperate woodland (North America and East Asia), Mediterranean (excluding the Southern Hemisphere but including California), and Southern Hemisphere (mainly dry climates of Australia and South Africa.

Each of these contains many excellent and ornamental and food plants, and many of these are “intermediate” in their ecological/cultural requirements and/or in their general appearance, so that they can be used interchangeably in some cases and also to make a smooth segue from one “theme” garden to another.

Montane and Alpine [should this include the North coast conifer belt?]

This includes the conifer-dominated landscapes of the higher latitudes and higher elevations of the Northern Hemisphere.  It does not include the very different high-elevation regions of the tropics and the Southern Hemisphere, which have a series of distinct and peculiar floras all their own: the cloud forests, paramo, puna, etc. or the cold and clammy lowlands of the southern high latitudes: Tierra del Fuego, Southern New Zealand, Tasmania etc.

  • Cool summers with rain
  • Freezing winters with snow

California is not exactly suited to truly alpine gardening, i.e. using plants (mostly perennial herbs) native to the severe, rocky screes and meadows above timberline.  We just don’t have a severe-enough climate, and worst of all (ironically enough with desert gardening discussed below) our wet, mild winters are a deadly challenge to most alpine rock garden-type plants, the only difference being that desert plants like warm, dry winters and alpine plants like cold, dry winters.  This should make it easier to grow alpines in a desert than elsewhere!

Fortunately, Californians have never gone in much for alpine rock-gardens—why battle against Nature for such small rewards?  We can and do, however, grow many montane plants from somewhat lower elevations.


North Coast vs. mountains, Northern California vs. Southern California

Neither is appropriate to Central Valley or Southern California

Rather limited selection, mainly conifers, some deciduous broadleafs (mainly aspen, but at lower elevations various oaks and others) 


This refers to the Western Hemisphere deserts only (North and South America) since the desert landscapes and desert plants of the “Old World” (in Australia and South Africa) are distinctive enough that they are given their own heading here.  You can, however, with some skill and plant savvy, get away with mixing elements from the two kinds of deserts without too incongruous a result . . . up to a point.  The North American desert par excellence is the Sonoran Desert—the type you will see in southern Arizona—and this unusually interesting and dramatic desert is a perfect example of why it is so difficult to really do justice to desert gardening here in California.  The desert has a rainfall regime that is exactly the opposite of ours:  unlike California, the major rains come in the hottest part of summer.  In this way the American deserts are much like the tropics except that the overall amount of rainfall is much less.  Winters in the low desert are moderate—as is most of lowland California (the high deserts, including the Mojave and the Great Basin, have much colder winters) and the summer heat is legendary—but so is that of the Central Valley and its foothills.  It is only those months of winter, with their roots sitting in cold, wet muck while the low sun scorches their south sides purple that make most of California scarcely bearable for most cacti and a lot of other desert plants.  And if you live on the cool, foggy coast on top of it, you will be able to grow a limited sort of desert garden indeed.  Even so, however, there are a few genera of desert plants (like the prickly pears and Trichocereus, some yuccas, agaves, etc.) that do surprisingly well even in such inhospitable settings.  For the most part, though, if you are serious about desert gardening and can’t move to Tucson, I hope you live somewhere in the Southern California crescent or else the San Joaquin Valley.  In other words, places with the warmest winters, hottest summers, and least rain.  (Ironically, you will have to water your desert in the summer, if you want it to thrive!)

In terms of what to grow in your desert, there is a huge array of cacti available, and also yuccas and agaves (century plans), prickly succulents that a lot of people mistake for cacti.  You could even try an ocotillo.  Other than the spiky succulents, the most characteristic plants of the American deserts are small-leaved shrubs and shrubby trees.  Most of the latter are legumes, i.e. they belong to the Pea Family, for example mesquites (Prosopis, several kinds), palo verdes (Cercidium and Parkinsonia, several kinds), acacias (several kinds), ironwood (Olneya), smoketree? (Dalea), _______ (Calliandra), and many others.  Many of these have masses of showy flowers, especially the various palo verdes, Calliandra, and the desert willow (not a willow at all but a relative of the trumpet vine and jacaranda).  Like the cacti, many of them are also armed with prickles.  All of them, however, have small leaves, usually finely compound, which are often drab green or grayish, and cast a light shade.  Many parts of the desert, especially the colder deserts, have only shrubs, mile after endless mile, and although there is a vast assortment of different shrubs to be found there, depending on where you are, there are also plenty of places where the only bush you will see for mile on endless mile (in the Mojave and Sonoran deserts) is the tenacious creosote bush.  Individually, though, it is a charmer, with its fragrant, shiny, little leaves and cheerful yellow flowers.  [Add note regarding the King Clone thing.]  Other miles and miles, this time in the Great Basin or high desert, are covered by silvery, fragrant Artemisia tridentata.  And there are plenty of others: brittlebush (Encelia farinosa), with its masses of yellow daisies, blackbrush (Coleogyne), Apache plume (Fallugia), bladderpod (Isomeris), Mormon tea (Ephedra), saltbush (Atriplex), and on and on.  I am particularly fond of another Sonoran desert specialty, jojoba or goatnut (Simmondsia), an attractive, clean-looking, dense, green shrub that has big, edible seeds that are also valuable for the very fine oil they contain.  This plant grows well even on the coast.

Tree or shrub, almost none of the desert plants show anything like “fall color”; instead the plants are all pretty much the same subdued, drab, grayish-and-olive color all year long, set off by the same pale, bare ground and gravel  in which they are rooted.  Only after a major rainfall does the ground come alive with myriad, tiny, colorful but ephemeral annuals, and even then the shrubby “overstory” stays pretty much the same.

But few desert gardens in California, sad to say, include many of the wonderful shrubs and legume-trees that make such a splendid, filmy counterpoint to the solid, bulky succulents.  So we return to the cacti.  As I said, the most forgiving species you can grow in the least favorable, coastal parts of California are the big prickly pears, with their large, multicolored, juicy fruits and edible pods (Opuntia ficus-indica, O. robusta, O. lanceolata, etc.) and the columnar Trichocereus species and their close relative the Echinopsis.  The latter have long, tubular flowers in various colors, and the former, which include many species (among which the well-known San Pedro), all with huge, white flowers and large, green, fuzzy fruits that pop open to reveal a firm, sweet, white pulp something between watermelon and cotton candy.  Another easy-to-grow columnar cactus (this one having fruit with a smooth, red skin and long, white, night-opening flowers) is Cereus peruvianus.  For more favored, drier, warmer climates there is a multitude of other columnar cacti (Lemaireocereus spp., Stetsonia, Myrtillocactus, Pachycereus, Pilosocereus, Azureocereus, Espostoa, on and on, even Saguaro), most with showy flowers and often delicious fruits.  And then there are the cute little miniature mammillarias, rebutias, etc and the more impressive barrel cacti (Ferocactus and Echinocactus) and of course the touchy but stunning little “strawberry cacti” (Echinocereus spp.) and a great many others beside.  There is nothing like a good cactus collection, but in California, a serious collection is a greenhouse enterprise.

[For desert section, add a sentence or two about using certain ornamental bunchgrasses, e.g. Muhlenbergia spp., Indian ricegrass, etc.]

To recap:

Desert landscapes are subdued in color overall, although many of the plants can have a brief show of very beautiful, colorful flowers.  Apart from the brief flower displays, there are no great seasonal changes like you see in deciduous woods or even the average garden; in this way, desert landscapes are much like the Mediterranean and, even more so?, tropical landscapes.  There are two major contrasting structural components to the desert flora:

  1. the bold, solid, “architectural” forms of the succulents, which in the broad sense means not only the cacti (dwarf clumpers to giant barrels to vicious chollas and prickly pears to tall, slender columns) but also, plants like ocotillo and boojum trees, and the various spiky, liliaceous plants like yucca and agave and sotol; and 
  2. the much-overlooked but dominant component, the rather drab, tiny-leaved, often spiny shrubs and small, charming legume-trees that make up 99% of the desert’s biomass and give such an artistic, lacy counterpoint to the succulents.  (Way too neglected—deserve much more appreciation and recognition and use), big columnar cacti (ditto).


California desert gardens nearly all focus almost exclusively on the succulent plants (usually without regard to continent or even hemisphere of origin, much less evolutionary/family relationships) and ignore the many beautiful small trees and shrubs with which the American deserts are so richly graced.  It is high time this situation is remedied, although, admittedly, the availability problem is in large part to blame.

Even among the cacti, the big, columnar types are often given short shrift, even though a great many of them are available, which is a great pity considering how many species there are and how beautiful and striking they are.

And, by all means avoid:

Conifers; deciduous trees, especially if they have fall color; anything with large leaves; bamboo; all “traditional” garden plants, like roses, lilacs, wisteria, daffodils, flowering plums and cherries, fruit trees; lawns, or ground covers of any kind (try to keep the ground as bare as possible—various kinds of gravel are a good way to go).  Cultural requirements are rather difficult for most of California, in the sense that desert plants want their rain in the summer and hate rain in the winter, just the opposite of our Mediterranean climate.  This means you should water your desert in the summer and continue to keep it as warm and dry as possible in the winter.  Excellent drainage is de rigueur in any case; nothing is worse for desert plants than cold, wet feet, even though they can take considerable dry cold or warm wet.  They also want consistent summer heat, something the foggy North Coast is notorious for withholding.  So keep your desert-garden fantasies to a very modest scale unless you live south of Santa Barbara or not far north of Bakersfield.  One more peculiarity: in the north, where the sun is low during the winter months, cacti often get their south-facing side badly sunburned an ugly red or purple from which they sometimes don’t recover.  So, counterintuitive as it might seem, the farther north (or coastal) you are, the more your cacti appreciate some shade, especially in the winter.  You might be amazed at the difference it makes, between a clean, healthy, unblemished plant and a livid, scarred and spotted, scabby mess.

One more cautionary note: one of the worst and most persistent scourges of cacti, especially in the greenhouse and in containers, is a nasty little cottony-looking pest called root mealybug, for which the best cure is not to bring it into the fold in the first place.  For this reason you should unpot any cactus you buy before taking it home and check for the telltale little white blotches around the outside of the rootball.  If you find any sign of mealybug at all, either leave the plant where you found it, or if you must have it, give it a good overnight soaking in a soapy solution of _______, lest you infect your whole collection.

The perfect architectural foil for a desert garden is a stunning courtyard, as much as possible of it paved with any attractive sort of stone (this will also help with the wet-water problem) and surrounded by light-colored walls of stone or stucco (I like pink for some reason).  Spanish-style architecture is good, with adobe and whitewash and lots of terra cotta and colorful tiles, and of course red tile roofs.

Such a desert-garden courtyard can be a deliciously inviting place to bask, lizard-like on a chilly winter day.

Appendix to theme garden section: Segues

[Add to section labeled “Foliage color . . . etc.”]

(Admittedly, all this is more suited to botanical gardens or huge private gardens rather than the chaotic, fragmented suburban landscape; nonetheless, here goes . . .)

Montane to desert.  The “high desert” or Great Basin flora is a perfect intermediate step between the conifer-dominated high mountains and the shrub-and-succulent-dominated low desert.  Plants that fit in this visual (and ecological) niche are the sorts of trees and shrubs you will see, for example, as you drive down the steep back side of the Sierras into Nevada.

These plants can be used to make a smooth visual transition between your desert garden and an adjacent or surrounding stand of conifers.  They are not numerous or flashy but they fill the rather specialized bill to a tee, and they are quite charming in their own right.  Small, rounded conifers are the choice par excellence, specifically junipers and pinon pines.  The latter are slow-growing but worth twice the wait in elegant charm (and potentially in pine nuts as well).  There are a remarkable number of species, including Pinus monophylla, P. edulis, P. quadrifolia, P. parryi, P. nelsoni, P. remota, P. pinceana, and _____, and every one is a treasure. 

Junipers can also be very charming, and they too come in quite a variety.  See if you can fid an alligator juniper!  The natural complement to these elegant little trees, on the desert side of the transition, is Artemisia tridentata and any number of other high-desert shrubs.

Others to do:  [drawing]

Australia/South Africa (two types?)

Segue to tropicals: “pseudotropicals” from Japan and Europe etc. (most hardy to 10 degrees) like Ilex, ivy, Rhododendron.

  1. Temp—Basically Eastern North America and East Asia (a bit all the way to Western Europe)

Segue to Northern Mediterranean

Mediterranean (also California, but no Southern Hemisphere) two types: macchia and savanna

Northwest California is example of segue to “montane” or at least conifer belt.

Southwestern California is segue to subtropical.

Tropical of two types:

“forest”—woody trees and vines, and palms; large, often glossy, bright green leaves; no seasonal change, only flowers.

“understory”—herbs (often giant like banana) also very large, glossy, bold leaves, bright green, changeless except flowers.

Northern temperate woodland:

Deciduous trees and shrubs with medium-size, bright, fresh green leaves and dramatic fall color, striking winter “skeletons”.  Northern bulbs and herbs below.  Showy spring tree-blossom effect.


Almost as drab gray-and-olive as desert but trees larger and bigger, mostly evergreen broadleaf, few conifers (rounded).  Two types (apply to California as well as Europe, replace macchia with chaparral and scrub and interspersed savannah, as in Europe, varying from dense trees to all grassland):

Savannah—trees with bare ground with ephemeral annuals.

Macchia—shrubs and subshrubs (“herbs” in the narrow sense)

In other words, type 1 is no shrubs (only trees and/or grassland); type 2 is only shrubs and rocks.


All woody? All evergreen.  No conifers.

South Africa:

Evergreen shrubs, no trees.  Mostly herbs and succulents and bulbs.

Tropical trees/shrubs/vines vary in the following ways:

  • Habit (tree, shrub, vine, etc.)
  • Size (huge to smallish)
  • Density (sparse, open to dense, making solid/dense shade)
  • Deciduous vs. evergreen
  • Trunk and branches green vs. normal
  • Trunk and branches spiny vs. normal
  • Leaf color (yellow-green to dark green; or red/bronzy new growth)
  • Gloss (matte to glossy)
  • Leaflet size (small to very large)
  • Leaf shape (simple, palmate, pinnate, simply lobed or finely dissected/divided)
  • Legume vs. other
  • Habitat (desert vs. subtropical vs. wet tropics to dry tropics to Mediterranean  (see next page for a discussion of foliage color for each region)
  • Aesthetics (foliage “clean” looking and attractive vs. ratty, partly dry/brown, torn and tattered
  • Cold hardiness (lots at the low end=10 degrees! And most at the high end, 28 degrees and above).  (An ersatz tropical garden for cold climates is easy to do by using the many hardy-to-10 degree “tropicoids” like ivy (yuck), camellias, etc.  I see this as the “Japanese effect”, although there are plenty of Northern European elements like ivy, vinca, cherry laurel etc.)

Make a “flow chart” connecting the most similar, most “harmonious” to grow together, using avocado as the quintessential do-able major tropical tree to be the foundation and core of a tropical garden (or better, grove)

Best understory for a tropical tree/vine collection is lawn, so that all gets adequate water.

Another? kind of tropical garden could focus on aroids, bananas, heliconias, epiphytes, gingers, tropical (clumping) bamboos, foliage plants, i.e. non-woody.  This too wants at least in part a deep-shade canopy. 


More fodder for “harmonious trees”

20 January 2002 noticed at Locatelli Ranch how well-pruned mature apple trees are perfect miniatures of English walnuts!

Also noticed how unexpectedly un-harmonious most tropical trees look together—entirely unexpected, although in native tropical environments there is total harmony.

In our climate, the most growable, most perfectly tropical-looking tree is avocado.  At Key West this would be complemented by similar-looking tropical trees giving deep shade:

Ficus spp., canistel, chicle, black sapote, mango

But for us, our limited palette of tropicals couldn’t be more diverse and incongruous, from ferny jacaranda and legumes to semi-deciduous species to “dry”-looking things including Myrtaceae to very open trees to light yellow-green citrus, and yuccas and palms and vines and shrubs.  My job is to group and relate all the diverse hodgepodge to come up with harmonious combinations and harmonious segues between tropical, Southern Hemisphere, desert, Mediterranean, etc. components.

Southern Hemisphere component is mainly: Myrtaceae and Proteaceae (others?).  Acacia also important but best included with legumes and/or deserts.

South African subset of tropical garden (veldt type, not fynbos)

  • Erythrina and maybe no other trees
  • Lampranthus, Delosperma, etc. groundcover for dazzling spring effect
  • Gazanias in all colors for a different mass effect
  • Among these groundcovers, punctuation in the form of :
  • Aloe spp.
  • Kniphofia spp., Strelitzia, Euphorbias? 
  • Lots of bulbs: Sparaxis, Gladiolus, etc. 
  • Even Oxalis spp. (including pes-caprae? if you have it already)

Tropical blue garden:

  • Jacaranda with lots of
  • Agapanthus (various forms, but masses of each)
  • Plumbago capensis
  • Ceratostigma?

All on nice green lawn?

For dry Mediterranean garden (of savanna type, not scrub type)

Geared for August, with olive, cork etc.  No groundcover, but punctuated with clumps of Amaryllis belladonna among rocks.