January is different in Southern California. While much of the country is frozen over, it's growing season here. Unscorched by the wan light of winter, fresh growth dusts the chaparral and woodlands. It's as if someone has been at the countryside with a highlighter and left behind a long, luminous wash of green. Free from competition from spring flowers and summer fruit, these wintergreens are a revelation — an achingly lovely spectrum — until one realizes that this Capricorn pasture comes with a catch.
FOR THE RECORD:
Shades of green —An article in last week's Home section on the biology behind the different colors in the garden said plants exposed to only dappled light put less nitrogen into photosynthesis. The plants, in fact, put less nitrogen into photosynthetic enzymes, which inhibit photosynthesis. More nitrogen is put into chlorophyll, which explains the deep green color.
Seeing green in the country can ruin it for you in town. Back in the city, the perfectly harmonized greens of the wild give way to an exotic cacophony. Olive trees with their leathery dark foliage and silver undersides sit in Irish green lawns. Yellowing citrus trees are coupled with blue-green fan palms. Feathery New Zealand tree ferns are partnered with birds of paradise.
Flower bed after flower bed, we display horticulture's answer to culture clash. If they were animals and not plants, the incongruity would be obvious: a camel and a seal, a tiger and roadrunner, a kiwi next to an elephant. But because they're plants, the only hint that they need different nutrition, sun, water is the color of their leaves. Their greens clash. They are hotbeds of green-on-green violence.
What at first might seem an aesthetic preoccupation is in fact a biological one. When greens clash, generally a plant is in the wrong place. Olive trees capable of living thousands of years will be lucky to last five in the sprinkler zone of a lawn. Learn how to read green, and more often than not, you don't even need to know the name of a plant to know whether it belongs where it is, whether it's healthy, stressed or dying. The pallor of the foliage amounts to nature showing the gardener how a plant is doing.
The art of the gardener is noticing.
David Lee, a professor at Florida International University in Miami, has been studying leaf color and function a quarter century. Leaves, he explains, are disposable "optical organs" in which plants harvest sunlight. Part of the green that we see on a sunny day is the glow radiating out from within those fluttering factories, where it is the job of the green pigment chlorophyll to absorb the light to use for energy to drive photosynthesis.
Two other compounds — carotenoids and anthocyanins, or more simply, yellow and red pigments — work alongside the chlorophyll. These backup pigments are thought to help deal with excess light, Lee explains. A leaf can only use roughly one-third of the light that hits it. The rest must be deflected so that the leaf doesn't burn up. These yellow and red tones are most welcome in new leaves, such as the pale frond of a young fern, or the fresh shoot of a rose bush. A slow release of chlorophyll into tender leaves allows them time to mature before demanding that they be up and photosynthesizing.
Yellows and reds in mature leaves return as preludes to death, the colors revealed as the plant pulls nitrogen, and with it the chlorophyll molecules that nitrogen helps comprise, back into the wood.
Beyond pigment, any number of variations in leaf structure affect how colors concentrate and light reflects from the plants, hence the shade of green that we see. There are big leaves, small leaves, flat leaves, curled leaves, leaves shaped like needles, lacy leaves, thin leaves, thick leaves, pale leaves, dark leaves, reflective leaves, scaled leaves, waxy leaves, fuzzy leaves. There are so many variations precisely because plants need all the survival strategies they can get, says John Gamon, a botanist at Cal State L.A. Unlike us, they can't get out of the midday sun. "Plants can't get up and run away," he says.
Harvard University biologist Noel M. Holbrook chooses the deciduous forests of the East, with their maples and beeches, to contrast with California as an example of how highly adapted indigenous leaf types are to their locales. Back East, she says, the mountain ranges are covered by deciduous forests whose trees have flat, porous leaves with fast growth, fast hydraulics, fast energy conversion and fast lives. The leaves are born in spring and dead by fall. By contrast, we don't have Eastern-style autumn leaf shows in California because the tender leaves of those dramatic maples would never make it to September. For a tree to hack it out west, its leaves need to be adapted to high light and low water.
As a rule, the leaves of indigenous Western trees tend to be smaller and tougher. The botanical term, a good Scrabble word, is sclerophyllous, from the Greek skeros for hard, and phullon for leaf. Pine needles and stout little cupped leaves of our western live oaks are both sclerophyllous.
The bigger an investment a plant makes in a leaf, the longer that leaf needs to last. In contrast to the ephemeral leaves of the East, the sclerophyllous leaves of the West are shed so slowly that they earn the plants the term "evergreen." Yet they are not greener. If anything, they are less green, tending to the gray, the blue, the silver, the olive. The chlorophyll may be the same as chlorophyll back East, but the thickness of the leaves combined with protective coatings give rise to a dusky Pacific palette. It can seem as if there is no end to their mechanisms for scattering light: hairs diffuse it, wax reflects it, scales bounce it every which way. These nifty defenses even extend to annuals. The seemingly delicate leaf of the California poppy appears slightly blue because of a protective film of wax.
The dusky Western leaf tones are in good company. They repeat themselves across the cradle of civilization, the Mediterranean basin, and wherever one finds similar climates — in central Chile, western Australia and the western Cape of South Africa. Here cross-cultural references can work, because crudely summed up, the Chilean, Australian, South African, Californian and Greek floras all have the same drinking habits and tolerate similar amounts of sun at comparable times of year. Tonally and ecologically, plants from most of these places work in California gardens. The trick is embracing them. Part of the shyness might even be that it feels vaguely un-American. Can it really be right that an Iraqi date palm sits in a Californian garden so much better than a Virginian dogwood and lawn?
There is no discussing the use of green in California gardens without stepping into the minefield about the rightness or wrongness of the suburban lawn. As the dinner party sociologists have it, the ubiquity of fast, wet, garish grass in Los Angeles is a case of the new West craving old Eastern respectability. Perhaps.
However, before accusing anyone of attempting a mini-Monticello in Monrovia, it would be an interesting experiment to try to buy a new house without a miniaturized approximation of a Jeffersonian green lawn around it. Getting a developer to leave out the lawn is like asking an automaker to leave out the polish. What grows faster than grass? Lawn is the cheapest instant garden to install, so developers slap it in with a sprinkler system to damp down dust around newly built homes. It then falls to the homeowner to pay up front to have the lawn removed, or pay later in the form of bills for daily water, weekly mowing and city pickups of the rotting clippings.
THIS is where it helps to be able to read green. If the landscaping decision is in favor of wet bright greens, then the challenge is to find plants that can take up enough water to keep up with California sun without wilting, have moderate enough growth that they don't turn gardening into a mowing and pruning treadmill, and whose bright undertones work together. Iochroma, pineapple sage and any of the many broad-leaved South American salvias can live with lawn and keep the garden clicking with hummingbirds.
If the decision is in favor of the dusky, darker native palette, then it's useful to select some middle greens — desert honeysuckle, rosemary, California gooseberry, mallows and even tea roses — that can pick up the lighter tones from neighboring yards. This will create visual connections with the landscape.
Whichever the homeowner decides, he or she should know how to read green and stay in tone, stick with wet greens or move to dry ones. If the color of the leaf of the specimen tree chosen for the lawn out front is a dusky Western hue, either chop down the tree, or rip out the grass and shut off the sprinklers. Western trees develop their small, tough leaves precisely because they make such economical demands on water. So exposing a native or drought-tolerant tree's feet to daily dousing by a sprinkler system is asking for problems. It promotes shallow root growth and poor stability, and in the worst-case scenarios, dank conditions can rot the roots out from underneath the tree. Either way, you could end up with a tree coming down on the roof of the dream home.
Murdering the lawn around a tree has virtues beyond correcting watering zones. Replace it with brown mulch and you might find that your eye registers the foliage for the first time, now that the greens aren't at war. However, for planting up and around trees, the possibilities for good greens increase when the grass goes. Suddenly the gardener can emulate what happens in woodland, and promote a verdant understory. According to Harvard's Holbrook, woodland-like settings can be the source of some of the brightest, deepest greens in the garden. Out of danger of too much sun, plants exposed to only dappled light tweak their nitrogen budgets, putting less nitrogen into photosynthesis and more into chlorophyll, so the plants green up. Gardening in shade is so often presented as a problem. But in California it's an opportunity for the gardener to use the cupped and ruffled deep British racing green leaves of coral-bells topped in spring by pink and purple flowers. Add irises, creeping Centennial ceanothus and native ferns, and you have a walk in the woods.
Nothing teaches a Californian home gardener about chlorophyll and disease more than citrus leaves. Tradition has it that California is all about oranges, lemons and limes, but in reality, they can be difficult to grow, and only a few locations along the traditional citrus belt of the foothill communities of Pasadena, Covina and Riverside are ideally situated for it. Alkaline clay in the basin guarantees problems with iron uptake, even after fertilizing. The problems are so common that chlorotic citrus leaves are textbook in diagnostic tests. The two most common problems are evenly yellowing leaves from light stress and yellow veining, a sign of iron deficiencies.
There are products, lots of them, to green up the leaves, but Gamon wonders if this isn't another case of an unhappy leaf telling us we are growing a plant in the wrong place. "A lot of these are problems created by plants that don't belong here, so then we have to pour all kinds of stuff on them and water the heck out of them."
GOOD gardeners have thought longer and harder about using green than decorators for the simple reason that they had better greens. Avocado-green refrigerators and hospital green walls were bad simply because the paint chemists couldn't do better. That's changing. While the last half-century has not necessarily made us better gardeners, it has done wonders for paint chemistry.
Philip Ball's 2001 book, "Bright Earth: Art and the Invention of Color," chronicles the long road to good color, including tolerable greens. It's not that we couldn't see good hues until very recently, he says. We couldn't make them. Technology had trouble synthesizing pigments for paints that match the greens found in nature. Green particularly had been in the dumps. The status of colors very much depended on human ability to reproduce them, then organize them on color wheels, charts, rainbows and even tongue forms. A now outdated stigma classed green as a mixed, not a primary, color, such as yellow and blue. Disapproval for mixed colors dated back to classical Greece, because of the chemical challenges of deriving good blends and then protecting them from muddiness. According to Ball, chemical mastery of mixing paints has occurred only in the last 50 years.
Then there was the small matter of us learning how to use them. Here in the U.S., much of the first four decades of improved color was lost to the bad taste of baby boomers, says Leatrice Eiseman, a consultant to the color gurus Pantone. (Think psychedelics, pop art and shag rugs.) Only now are our eyes becoming sophisticated and our confidence with color maturing.
Smart folders, smart offices, smart filing cabinets, smart Volkswagens now all come in zingy lichen greens. Eiseman, who forecasts color trends for a living, confirms that green has made a comeback, and now seems unstoppable. Not long ago, she says, the world agreed with Kermit's lament, "It's not easy being green." Today, she says, "It's a whole lot easier." Positive associations out of the environmental movements spilled over into industry in the '90s, she thinks. "IMac green swept over the world of industrial design. Then there was Shrek. Even M&Ms started using Shrek-green."
Shrek-green is easier to get right than sage, she says, because Shrek's a cartoon. Moreover, how plant leaves hold light — literally radiating green from the inside out — and how flat paints reflect them are two very different things. Still, greens have never been more alluring, she says, even if the names don't match the colors. Sure enough, over in the Benjamin Moore fan decks, "honeydew" looks like a mint cream and "chopped dill" looks like olive, but what's surprising is how good the greens are, how full of light, brightness and charm. It seems faintly incredible that the paint company catalogs advertise not just green samples, but rooms decorated in blushing shades of green.
For color forecasters like Eiseman, a good part of understanding green is producing colors that will "communicate" for their corporate clients, i.e. sell things better. Books on the subject bear pearls. Green, it emerges, is "especially appropriate to either the packaging or actual color of personal hygiene or beauty products."
Such insights aside, the rise of green in industrial design and interior decoration can only be a good thing for gardens. While the colors themselves will never be comparable — green in paint comes from chemical companies, green in plants come from our three earthy pigments, sunlight, wax and hair. Yet painting with green, dressing with green, noticing, discussing green, simply seeing green has to help us become better gardeners. By the time you are thinking about planting impatiens under the olive tree because you saw it at the children's garden at the Huntington, you might look twice at the watery brightness of the Papuan flower's leaf, and the dark greens of the Mediterranean tree, and think again.
At that moment, in what seems like sunbaked dreamtime in the garden, gardening becomes science and yard work becomes artwork.
Emily Green can be reached at firstname.lastname@example.org.