Gardening during a drought
Gardeners garden for many reasons. There are both similar and different purposes for growing edible and ornamental plants, but all gardening has the common goal of keeping plants alive. That can be a challenge during prolonged periods of drought, which California's gardeners are experiencing now.
For several months, we have received a series of local and statewide regulations on water conservation, including an emphasis on outdoor uses, which include garden irrigation and other activities that add to a large percentage of household water use.
All gardeners should respect local water use regulations.
The most direct strategy for gardening during a drought is simply “use less water in the garden.'
We should, however, consider the broader purposes for our landscapes. A thoughtful advisor on this topic is entomologist Douglas Tallamy, who recommends four objectives for every landscape:
• Support the food web.
• Manage the water shed.
• Support pollinators by using a diversity of plants that the specialist pollinators need • Sequester carbon.
Each of these objectives has implications that deserve unpacking, but for today's column we focus first on the objective to manage the water shed.
The first consideration should be to use water wisely. For plant management, this means providing water only where and when the plants need moisture. This can be accomplished by hand watering, at least for small numbers of plants. For larger gardens, the recommended strategy is to use drip irrigation, rather than wide spraying, to deliver water to each plant's roots. The corollary for plant irrigation is mulching. Maintaining a threeor four-inch layer of mulch around plants reduces evaporation of precious water and discourages weed growth.
Managing a drip irri
gation system includes scheduling and regulating uses to meet each plant's moisture needs and checking periodically for leaks. The loss of a single emitter on a drip system can waste a lot of water during each scheduled irrigation session.
An important guideline for water conservation in the landscape is to minimize lawn irrigation. Lawns have been normalized as elements of the residential landscape. Still, environmentalists and water conservationists criticize lawns. From their perspectives, lawns require substantial uses of water, artificial fertilizers, and broadleaf herbicides to maintain a desirable appearance. They also fault lawns as monocultures that do not support the food web and support pollinators.
If your garden includes a lawn area, California's drought and other considerations suggest either reducing the size of the lawn or eliminating it altogether.
The third water conservation guideline is to select drought-tolerant plants, rather than “water
hogs.” Tropical plants, e.g., orchids, are attractive to some gardeners and can be enjoyed in a greenhouse environment where water use can be controlled with care but including waterdependent plants in the landscape requires substantial amounts of water.
In this column, we have often recommended “summer-dry plants,” which are plants that have are adapted to the annual rain pattern that are typical of California and the world's other Mediterranean climate regions. This category still includes some plants that grow best with moderate irrigation levels during the rest of the year, so it's worthwhile to know each plant's overall water needs (see “Advance Your Knowledge,” below).
With Tallamy's objectives in mind, the ideal plants for gardening during a drought are California natives. They thrive in California's climate, they are integral to Nature's food web, and they have evolved with specialist pollinators that depend on our native plants.
For more on the relationship of native plants and pollinators, read Tallamy's popular books, including “Bringing Nature Home,” “Nature's Best Hope,” and “The Nature of Oaks.” He has also shared
his ideas online: browse to Youtube.com and search for “Tallamy.”
This brings us to the upcoming plant sale by the Santa Cruz Chapter of the California Native Plant Society on Saturday at the UC Santa Cruz Arboretum & Botanical Garden. The sale begins with a members-only session from 1011 a.m. (you could join at the sale, I believe), and opens for the public from 11 a.m. to 2 p.m.
The sale includes nine annual species and 141 perennial species. To study the lists of plants that will be available at the sale, visit cruzcnps.org/plantsales/. There will be limited numbers of each plant species, so your early arrival will help you to acquire the plants you want.
This event provides an excellent opportunity for gardeners to prepare their gardens for drought conditions, support the food web, and support specialized pollinators.
Advance your knowledge
To learn about California native plants, visit the Annual Wildflower Show presented by the Monterey Chapter of the California Native Plant Society on Saturday and Sunday at the Carmel Women's Club, Ninth and San Carlos, Carmel. This show, which has
a 60-year tradition, was suspended by COVID-19 in 2020 and 2021, and will have its glorious return in 2022. The event includes specimens of wildflowers that are blooming in Monterey County during the current drought period.
It's happening during the plant sale in Santa Cruz, so interested gardeners could make this a native plant weekend.
For plant-specific water needs information, discover WUCOLS IV, which the current version of the Water Use Classification of Landscape Species. The California Center for Urban Horticulture, University of California, Davis, developed the WUCOLS IV database, which includes 3,546 entries. Visit ucanr. edu/sites/WUCOLS/ to look up the water needs of any plant of your interest.
For assistance in plant selection, explore the Calscape Garden Planner (gardenplanner.calscape.org/). This is a very practical online tool for planning a garden of native plants. It is a resource within the California Native Plant Society's online database of nearly 8,000 plants native to California (calscape.org/).
Enjoy your garden!