CHAPTER FOUR

      Does anything ever stay the same? Seen from the perspective of geologic time, we do indeed live on a restless earth. Land masses shift, plants and animals evolve and migrate, and climates undergo enormous variation. MichaelBarbour; BrucePavlik, Frank Drysdale, and Susan Lindstrom, 1993

      The next time you howl in delight like a wolf, howl for unstable aperiodic behavior in deterministic non-linear dynamical systems. Jack Turner, 1996

      Over the years, I have turned from frustration at garden events that thwart my plans to some degree of acceptance and a greater degree of interest. With increasing insouciance, I watch the garden take its own direction. The back-yard restoration gardener learns the benefits of accepting gardening as an evolving situation, appreciative of each opportunity to factor in more complexity. In the privacy of your back yard, it has less to do with success or failure, more to do with lessons to be learned from the uncertainty that accompanies a growing garden.

      In my garden on the north central coast, we occupy the shifting interface between northern and southern coastal plant communities. A wet year favors the plants of the north coast forests, including ferns, Pacific wax myrtles, Pacific reed grass, flowering currants, California hazels, red woods, and red elderberries. A dry year favors plants of the coastal scrub and grassland communities.

      Coyote bush, monkeyflower, lizardtail, and California sagebrush are the main coastal scrub plants in our area. For ten years, repeated groupings of these species have been the visual and philosophical heart of my garden. It is the place where quail hide and huge spider webs are newly hung each summer morning. Many people at our open houses pause with me to sniff the fragrance of the silvery gray foliage of Artemisia californica, California sagebrush.

      One year, severe storms battered the coast. Parts of the garden were flooded for months, and California sagebrush, an essential silver element, rotted and died. This event caused me to note that California sagebrush in our area is usually found on slopes and banks. In drought years, it was able to thrive in my flat garden, but that year of almost constant rain into early summer exceeded the tolerance of its roots for continual moisture. Until garden events brought it to my attention, I had not made this obvious observation about sagebrush. The extremes of temperature, moisture, and exposure ultimately determine what grows in a given spot.

       A Plant Is Not a Couch

      I am aware of the anxiety some beginning gardeners feel and the personal responsibility they take for plant losses. They understandably seek to know why the plant died, so that they can avoid this failure in the future. More experienced gardeners develop a sense of how difficult it is to make inferences about gardening events. Sometimes we “know” why something died, and sometimes we don't. We can make good guesses, or, at the other extreme, we can send samples of dead plants for laboratory analysis, an expensive procedure for the home gardener and one that may still not yield conclusive information.

      In the realm of living things, a multitude of factors determine events; where plants are concerned, soil problems, moisture problems, disease problems, temperature problems, weed problems, and different combinations of the above are involved.

      Using local native plants, the gardener can always return to the natural model, to compare situations with the home garden. The land surrounding a house has often gone through changes not apparent to the present occupant. The native soil may have been buried under fill or carted far away. Plants provide clues to the status of the soil. Colonizer plants, like lupines and red maids, will change the soil, making conditions favorable for longer-lived tree and shrub species. Plants like coyote bush, adaptable to many soil conditions, make good nurse plants for small oaks and native grasses.

      “A plant is not a couch” has been our motto for some years, somewhat cryptically calling attention to the element of uncertainty that is always part of dealing with living things. We hope to encourage our gardening customers to relax, take chances, be of good heart, take the losses lightly, and enjoy themselves.

      This motto was inspired by my daughter's riding instructor. During her lesson, one of the pupils was nervous. “What if my horse bucks?” she asked the instructor.

      “We can't be sure he won't,” she replied. “A horse is not a car. We just hope for the best.”

      And a plant is not a couch. Plants are not furniture. Working with living things is much better than that.

       Perturbation

      “Perturbation”—disruption by fire, flood, wind, and earthquake—renews landscapes, creating opportunities for different species to flourish. When bare soil occurs as a result of some form of perturbation, it is always interesting to see the changes that follow. Species that appear first in bare soil are called “colonizers.” They are often nitrogen-fixing, sun-loving, and short-lived, including annuals like red maids and sky lupine, biennials like coast plantain and coast wallflower, and shrubs like blue-flowering lupine. One advantage of creating perturbation in the garden is that new food webs will appear. They may be temporary, as other plants take the place of the colonizers, which have created situations more conducive to the growth of the longer-lived plants. The temporary and the short-lived merit a place in the garden too.

      Fire, a major agent of perturbation in California, may be a useful tool for landowners with significant acreage. In more urban areas, the gardener can be the agent of change, substituting pruning techniques (see the section on pruning in chapter 10) for natural occurrences. Severe pruning—six inches to a foot above the ground—can function as a “fire-equivalent,” creating vigorous new growth in crown-sprouting shrubs like elderberry, California sagebrush, coyote bush, some ceanothus, toyon, holly-leaf cherry, and some manzanitas. Flooding may bring new life to thicket-formers like willows, twinberry, alders, and creek dogwood, and pruning can simulate that form of perturbation too.

      In larger gardens, the homeowner may want to borrow a concept from chaparral management techniques, wherein different portions experience perturbation at different times, so that a mix of different-aged stands exists at the same time. Opportunities for different populations of mammalian, insect, and avian species will be created.

      Pruning regimes can reflect this goal. Species that follow disturbance can be given their opportunity in the garden by use of a sequential pruning schedule. Prune a section of the chaparral garden one year, let it regrow, and prune a different section the next year. Perturbation, creator of diverse habitat opportunities, becomes a valuable technique in your gardening repertoire.

      “I have this bank behind my house”: Erosion Control

      One kind of change with a bad reputation is the kind called “erosion,” the downward movement of soil on slopes. The Soil Conservation Service, formed as a response to the Dust Bowl (and now called the Natural Resources Conservation Service), has done an admirable job of alerting the public to the loss of topsoil through soil disturbance of various kinds. When homeowners see a bare bank created by road or house building, alarm bells go off. An irresistible desire to scatter seed of or plant fast-growing species is unleashed. In the name of erosion control, we have loosed on our wild-lands many destructive plants, including iceplant, capeweed, European beach grass, all kinds of ivy, and the perennial and annual Italian rye grasses.