UNITED STATES—Gardening is quite unnatural. It involves unnatural cultivation of mostly unnaturally exotic (nonnative) species of plants. Irrigation delivers more water than seasonal rain provides. Fertilizers contribute more nutrients than endemic soils provide. Pesticides, if necessary, inhibit proliferation of pathogens. Nature simply could not accommodate such demands.

Not only is gardening unnatural, but it also interferes with established ecosystems. Many aggressively invasive plants were formerly desirable exotic plants that naturalized. Many pathogens arrived with exotic plants. Several naturalized plants have potential to distract native pollinators from native plants that rely on their pollination. It is an ecological mess.

Nonetheless, it works. Gardening within the constraints of nature would be unproductive. Most residents of California inhabit chaparral or desert climates that originally sustained limited vegetation. Such limited vegetation sustained a very limited indigenous populace within relatively vast areas. Modern residential parcels would be completely inadequate.

Gardening involves compromise.

That is the justification for gardening, whether for sustenance, or merely to beautify home environments. Unnatural breeding continues to improve performance of many useful and appealing plants. Unnatural horticultural techniques generate more desirable vegetation within confinement of urban gardens than would naturally inhabit a few acres in the wild.

Nature remains relevant though. All plants originated within nature somewhere. Besides their basic requirements, exotic plants prefer environmental conditions that are similar to those of their natural origin. Some tropical plants crave more warmth and humidity. Some plants prefer more winter chill. Most popular exotic plants rely on supplemental irrigation.

Physical characteristics of many plants necessitate special accommodations also. Roots of plants that naturally compete in dense jungles are likely to damage pavement. Without adequate pruning, native plants that naturally exploit burn cycles can become perilously combustible. Many vines naturally try to overwhelm nearby vegetation and infrastructure.

Highlight: Red Willow

Of the few native species that share the same designation of ‘red willow’, Salix lasiandra, is likely the most common locally. However, it has a few other common names, including shining willow and Pacific willow. For those acquainted with it, recognition is easier than nomenclature. It is not a problem though, since red willow is rarely an intentional choice.

Red willows, including less common species, grow wild in local riparian situations. They sometimes sneak into home gardens, particularly if irrigation is generous. Their rampant growth is susceptible to spontaneous limb failure. Pruning can compensate for structural deficiency of young trees. However, trunks typically succumb to decay within thirty years.

Mature trees are mostly less than thirty feet tall, typically with low branches, and possibly with a few elegant trunks. The gray or light brown bark is finely furrowed. The deciduous foliage has a slight sheen, and then turns brownish yellow prior to autumn defoliation. Its narrow leaves are about three inches long. Twigs are yellowish or green rather than red, as it implies.

Horticulturist Tony Tomeo can be contacted at tonytomeo.com.