Drought alternative: Dry Gardening
Adapted from the "Growing Concerns" column
February 22, 2014
K. Reka Badger, Santa Barbara News Press
As the drought deepens and water bills creep ever higher, many cultivators are creating more self-sufficient landscapes. By grouping select species according to nutrient needs, they can convert thirsty beds into dry gardens, eliminating the need for regular supplemental irrigation.
The practice of dry gardening is closely related to dry farming, a term that describes the cultivation of crops without irrigation, particularly in areas receiving less than 20 inches of rain per year. It relies upon rainfall and the ability of plants to find underground moisture to supply their water needs. The success of dry farming depends upon efficient storage of moisture in the soil, as well as choosing the best species to take advantage of available water. Plants well suited to dry gardens generally prefer soil with good drainage and a neutral to slightly alkaline pH.
Not all plants can survive on low water levels, so it’s critical to select the proper species. Plants with small leaves - especially blue or gray ones - and/or root structures adapted to store water offer the best results in dry gardens.
Wonderfully adapted to arid conditions, California natives, such as buckwheat (Erigeron sp.), white sage (Salvia apiana) and manzanita (Arctostaphylos sp.) thrive as companion plants. Shrubbier specimens, including lemonade berry (Rhus integrifolia), flannel bush (Fremontia californica) and most varieties of ceanothus, also combine to make durable, attractive groupings.
Spacious dry gardens could include towering incense cedar (Calocedrus decurrens) and locally-adapted native oaks, for welcome scent and shade. Additional native trees that fit the bill range from lovely coast silktassel (Garrya elliptica) to aromatic California bay (Umbellularia californica).
For shady spots in the dry garden, native candidates include Catalina Island bush snapdragon (Galvezia speciosa), western sword fern (Polystichum munitum) and Catalina perfume (Ribes viburnifolium). Taller species, such as western spice bush (Calycanthus occidentalis) and Oregon grape (Mahonia aquifolium), lend vertical interest.
Weeds compete with desirable plants for moisture and nutrients, so remove them before planting in the dry garden. Most drought tolerant plants prefer less fertile soils, so there’s generally no need to amend the beds. To conserve moisture around roots, spread a layer of mulch at least two inches but not more than four inches deep. Space plants a little farther apart than you normally would, and place rocks and boulders in strategic spots to help shade roots and give the garden a natural look.
A garden designed to survive without supplemental water is far more resilient than a collection of coddled plants. The blooms may be smaller, but the colors tend to be more intense, the plants less prone to water-borne diseases and the entire garden a smart response to water-challenged times.
K. Reka Badger is a Master Gardener who writes from her home near Templeton, California. Her column “Growing Concerns” appears in the Santa Barbara News-Press every other week in the Home & Garden section. The Santa Barbara News-Press has generously granted the Garden permission to repost this column.