It's a given: The day is fast approaching when wars will be fought over water rather than oil. Already, heated confrontations have flooded the media, pitting such unlikely combatants as the farmers in the Klamath Basin against the saviors of the coho salmon, and the peasants of La Paz, Bolivia, against a consortium of private water companies.
Even Secretary of State Colin Powell has been overheard to plead with his Mexican counterpart, "Got any water for me?" in reference to a long-standing treaty between the two countries.
The issue is water and the issue is global. There simply is not enough of the stuff to go around — and one of the first casualties of the water wars will be our lawns and gardens.
Does this mean that those of us gardeners devoted to lush landscapes crammed full of thirsty perennials are constrained to cultivate only cacti and succulents?
No — far from it. Not to disparage cacti and succulents, but a gardener's water-wise choices are vast, far more extensive than those familiar desert denizens.
Some of the most interesting gardens in the world flourish in South Africa, Australia and along the Mediterranean coast — think of the magnificent seaside gardens of southern Spain, the rich and varied flora of northern Morocco. These parts of the world share our climatic conditions: wet, gray winters and bone-dry summers, yet these Mediterranean gardeners and South African botanists have cultivated a spectacular array of plants that will flourish in a dry garden.
So let us borrow their wisdom and, as a start, define our garden's structure by selecting trees and shrubs that require minimal water to frame our landscape.
We are all familiar with acacia, ceanothus and oleander, those Northern California basics blanketing the sides of our freeways, but the plant world abounds with many other varieties of trees and shrubs that thrive in dry soil.
For instance, the revered coast live oak, Quercus agrifolia, is a true lover of parched soil, and will die if watered in the summer. It's a splendid choice to mark a garden's edge.
Another handsome specimen, also evergreen, is the Australian willow, Geijera parviflora. Never heard of it? Well, it's a favorite in the Outback, where water is scarce, but don't let the common name fool you; it really belongs to the citrus family and shares only the grace and not the thirst of the familiar weeping willow. Its drippy blue-green leaves and tiny white flowers will lend elegance to any patio setting, and the Australian willow is tough enough to survive even as a neglected street tree.
A soft-needled conifer that flourishes in a water-wise garden is the genus cedrus. Although all four species are majestic, a particular favorite is C. deodara, a stately gray-blue beauty that can exceed 75 feet in height and 35 feet in width — not your typical dainty ornamental.
The deodar cedar needs fast-draining soil and good sun along with ample space, a coveted commodity in Northern California. Not to worry; even the smallest backyard garden can accommodate one of the newer cultivars, say, 'Snow Sprite', whose soft, silver-green foliage is etched in ivory, a true prize that tops out at only 12 feet.
Another evergreen lovely is Olea europaea, the European olive, which made its debut in California in the 18th century. Introduced at the mission in San Diego by the Franciscans, early specimens were prized for their fruit and the extracted oil.
Modern-day gardeners, preferring to buy their oil already pressed, should select one of the nonfruiting varieties, such as 'Swan Hill' or 'Fruitless'; otherwise, olive drop can create an awful mess in the garden.
Beautiful gray-green leaves flipping to silver in a light wind complement the rough shredded bark of the trunk. The olive can tolerate poor soil, heat and drought, almost anything the home gardener can toss at it. A slow grower, it may reach 25 feet in as many years, but don't flinch at pruning the olive to display its dramatic branch patterns. It's tough. It can take it.
Yet another evergreen beauty is the ancient favorite Laurus nobilis, whose glossy, dark green leaves crowned the head and marked the victory of competitors in the ancient Greek Olympic Games. Today the most familiar use of the pungent leaves of the sweet bay is to form the backbone of a bouquet garni, respected by every cook determined to add a little zing to a chicken pot-au- feu.
Although the natural form of the bay tree tends to be shrubby, with many ground-level suckers, the cultivar 'Saratoga' can be easily trained into a tree form. Stippled with clusters of small yellow flowers in the spring, the laurel tree becomes heavy with purplish black fruit when the temperatures fall.
The structure of our dry garden would be incomplete without the inclusion of a couple of deciduous trees such as Tilia tomentosa, noted for its lovely heart-shaped leaves flocked in silver, and Lagerstroemia indica, commonly known as the crape myrtle and beloved for its spectacular flower display in late summer.
Tilia tomentosa, commonly known as the silver linden, is resplendent in spring with fragrant lime-green blossoms and produces clusters of olivelike fruit later in the year. But bee lovers beware: Its flowers are toxic to your fuzzy friends.
The crape myrtle, whose branch tips are covered with masses of crinkly clusters of small flowers in the heat of summer, is one of the slower-growing trees, rarely exceeding 25 feet. Tolerant of almost all conditions except coastal winds, this handsome tree dresses up the garden in all four seasons. Brilliant foliage brightens up a lethargic landscape in fall, and showy smooth gray bark forms a stately backdrop in winter.
Because it blooms on new wood, all pruning should be done in late winter or early spring before the new growth emerges. Some of the best-loved cultivars, all named to honor American Indian tribes, are 'Natchez', which blooms with white flowers; 'Seminole', decked out in late summer in rich pink flowers; and 'Tuscarora', awash with brilliant crimson blossoms.
Now that the structure of the garden has been defined by the trees, it remains to fill in the frame with some of the extensive varieties of shrubs that are indigenous to Mediterranean climates, those that will flourish with little or no water.
Turning first to those noted for their exotic foliage, a couple of sun lovers are Leucadendron argenteum, or silver tree, and Elaeagnus x ebbingei.
If you are out to make a gardening statement, you need look no further than to the striking South African relative of the protea, leucadendron, whose large pointed leaves are cloaked in long silky silver hairs.
Although highly drought tolerant, the silver tree is a bit fussy about its roots, rebelling when moved and insisting on perfect drainage and sandy soil. Even though this drama queen demands center stage, leucadendron plays well with other foliage plants, the phormiums, and drought-resistant grasses such as Pennisetum setaceum 'Rubrum', or red fountain grass.
Another silver-leafed beauty is Elaeagnus x ebbingei, a variety of silverberry, which can tolerate some shade but performs at its silvery peak with a healthy dose of full afternoon sun. Although it rarely exceeds 10 feet, elaeagnus can be pruned radically, making it a likely candidate for an evergreen hedge or screen. The masses of tiny, fragrant silver flowers that appear in the spring are transformed by cooling temperatures into vivid red berries that make a tasty jelly. Here is a plant to delight all the senses and one that performs with only minimal water.
If your coast live oak has created too much shade to support either of these silver stars, or your garden is not drenched with sun all day long, do not fret. Here are a couple of shade lovers noted for their striking foliage as well as their water-wise needs — not as dramatic as the queens of the silver stage but handsome cast members nonetheless.
An old favorite, Mahonia aquifolium, the state flower of Oregon, boasts large, glossy holly-like leaves, bronze when new, dark green when mature. In addition to its good-looking foliage, it is covered with masses of yellow flowers in the spring that turn to edible blue-black berries in the fall, the source of its common name, the Oregon grape.
To help the mahonia retain its bushy shape, put it on a three-year plan: Remove one-third of the canes every year right down to the ground. Plant it in front of a boring background such as a cinder block wall or concrete foundation, and its stately beauty will capture and distract the eye.
For a totally different look in the garden, consider Nandina domestica, or heavenly bamboo, an evergreen native of Asia familiar to many gardeners seeking shade-tolerant shrubs. Don't be put off by its common name; Nandina belongs to the barberry family, although the only obvious resemblance to the common "pricker bush" is the masses of red berries produced in the fall. The similarity stops there.
Heavenly bamboo, so named because of the Asian tradition of planting it in temple gardens, is characterized by lacy foliage that emerges bronzy pink in spring and turns to light green in summer and fiery red in winter — quite a kaleidoscope of color. A handsome cultivar is 'Gulf Stream', which sports blue- green foliage. As with the mahonias, cut out one-third of the oldest canes each year to keep it from getting leggy.
Perhaps you want more variety in your garden than plants noted just for their dramatic foliage or elegant structure. You want some fragrance, you want some color. You can have these features, plus you can have them in shrubs that require little or no water.
A Chilean transplant with a well-known aroma is Aloysia triphylla, lemon verbena, a rangy semi-evergreen shrub that looks best in the back of the garden, where its long legs can be hidden by shorter plants. The leaves of lemon verbena are used to flavor teas and iced drinks, and the scent of its oil will permeate the garden and draw hummingbirds. Like most verbenas, it wants full sun, good drainage and, yes, little water.
Another shrub that emits a powerful scent is the strawberry tree, Arbutus unedo, which smells just like the fruit. This handsome evergreen specimen is blanketed in fall and winter by clusters of creamy flowers and, at the same time, strawberry-size balls of yellow and red fruit, which are edible but relatively bland.
This western Mediterranean native can take radical pruning and will reward your efforts by showing off a twisted and gnarled trunk covered with rich red- brown shredding bark.
You want flowers as well? Then take a look at that big, blowsy beauty Romneya coulteri, the matilija poppy. Crowned from late spring to early fall with white crepe-paper flowers surrounding a core of golden stamens, this Mexican transplant loves the sun and thrives in sharply draining soil. Once it has settled in, ration its water during the summer; otherwise, it can be invasive. To further discourage its wandering habit, cut it close to the ground in late fall. Look for the cultivar 'White Cloud', a profuse bloomer with big fat flowers flanked by silver green foliage.
A daintier version of the brassy matilija poppy is the laurel-leafed Cistus laurifolius, a carefree Moroccan lovely whose deep green leaves are smothered with crinkly, small white flowers all summer long. Despite their delicate demeanor, don't be fooled by these rockroses; this is a tough shrub, noted for its love of poor, thin soil and meager water.
Another member of the clan is the ethereal Cistus skanbergii, a mass of gray-green leaves loaded with sprays of shell-pink flowers that will remind the eye of an English cottage garden. Although it appears as fragile as a Southern belle, this lovely plant flourishes in the barren mountains of Greece, where the soil is rubble and the water minimal.
Give all members of the Cistus family plenty of sun and good drainage, but take care: They hate humidity and cannot tolerate heavy pruning, so be gentle with your shears. Tuck a cistus in beside a warm rock in your dry garden and enjoy the show.
Common to the five worldwide Mediterranean climates is the uniformity of growing conditions. So it's hardly surprising that members of the same plant family share the same cultural needs, even though they may have grown up oceans apart.
In the far-flung mallow family, for example, both the Australian Alyogyne huegelii and the South African Anisodontea x hypomandarum enjoy arid soil and lots of sun. Either or both of these well-mannered beauties will add a hefty dose of color to your dry garden.
Anisodontea, the cape mallow, resembles a miniature version of that Mediterranean native, the hollyhock, seldom growing taller than 4 feet. Just like that old-time favorite, the stems of the anisodontea are massed with tiny rose-colored blossoms from early spring to late fall.
Its Australian cousin, the blue hibiscus, sparkles with a show of delicate flowers at the tips of deeply lobed dark green leaves. The hibiscuslike blossoms of the species range from lilac to pink, so if you simply must have the blue variety, choose one of the cultivars, either 'Santa Cruz' or 'Monterey Bay', and you will not be disappointed. To encourage flowering, prune both of these mallow members just after the final burst of color, and once they are established, cut back on the water.
Another family of plants that flowers and flourishes in a dry garden is the extensive mint group, which includes not only the familiar spearmint and peppermint but also oregano, salvia and two choice flowering shrubs, Westringia fruticosa, or coast rosemary, and Teucrium fruticans.
Coast rosemary, as the name implies, tolerates salty winds and coastal conditions, making it a prime choice for the seaside garden. As a bonus, westringia blooms in midwinter through the spring, just when all gardens look a little long in the tooth. This Australian native sports fine gray foliage and tiny white flowers, a striking textural contrast to other shrubs. To help it keep its round shape, shear it back right after flowering.
If your garden cries for color, choose the light lavender cultivar 'Wynyabbie Gem', or, for a blue accent, consider its striking Mediterranean relative, Teucrium fruticans, or bush germander. It is well-mannered and not fussy about soil or water. It too can handle the ravages of a coastal environment, setting a profusion of lavender-blue flower spikes amid silver- gray foliage almost all year long. It blooms on new wood, so thin it and prune in late winter before the new growth breaks out.
So when the water restrictions come down, as they will one day, and when the neighbors are mourning their brown lawns and dying plants, your dry garden will be aglow with silver-gray foliage plants and a vast array of flowering shrubs. Sketch out the structure, then fill in the spaces and disconnect the irrigation system.
E-mail freelance writer Sandra Gorry at home@sfchronicle.com.
© 2003 San Francisco Chronicle