Native plants are now in vogue in California, but not necessarily for all the reasons they should be. Our state’s severe, four-year drought is largely responsible for all the attention natives are now receiving. That is because, once established, natives generally need far less water than many of the plants historically used by landscaping companies and many landscape designers. So using natives not only can save lots of water, but also lots of money.
Native plants are indigenous to our state. They evolved here over time, adapting to the local climate, and still occur naturally in our remaining wild areas. Most of the common landscaping plants in this region are from other parts of the world. They evolved in different ecosystems with different soil organisms, different beetles, butterflies, birds, lizards and other wildlife. Many plants in this region, but certainly not all, require moderate to high amounts of water to thrive. A few examples of such plants here include azaleas, rhododendrons, redwoods, Japanese maples, red maples, purple leaf plum and, of course, grass.
Why does any of this matter? First, it helps to remember that our climate in central Contra Costa County is naturally semi-arid, similar to that of the Mediterranean, with long hot dry summers. The only precipitation comes during the winter, and lately we’ve been getting minimal winter rain. Native plants are adapted to this weather regimen, which is why they tend to need less water.
But there are a number of other reasons to favor native plants over non-natives, and most people are not aware of them. The first one was alluded to above. Native plants support the local ecology, which continues to be destroyed due to human activities. Consider how much of our natural areas have been lost to development, or damaged by oil spills, extracting and burning fossil fuels, using nitrogen fertilizers, and invasive species.
While creating new landscapes using native plants can never replace lost natural habitats, they can help provide an important “bridge” to nearby remaining wild areas. And because this part of central Contra Costa County lies adjacent to these areas, how we choose to re-landscape areas where grass is being removed is likely to make a difference. However, no one is advocating removing any established non-native plants here or in people’s private gardens. But the more native plants that we add to our landscaped areas, the more we will be helping all wildlife survive despite their diminishing and fragmented habitat. This is particularly true if we create plant groupings that contain sufficient numbers of individual species so they can be found more easily by insects and birds.
This landscaping practice is sometimes referred to as restoration gardening. It is one that everyone who cares about our environment can support. The best scientific analysis I have found on why and how native plants sustain wildlife and promote healthy ecosystems is found in a book written by Douglas W. Tallamy titled, “Bringing Nature Home: How You Can Sustain Wildlife With Native Plants.” Two books written by Judith Larner Lowry describe why and how to create sustainable landscapes and are also recommended reading. They include “Gardening With a Wild Heart: Restoring California’s Native Landscapes at Home” and “The Landscaping Ideas of Jays: A Natural History of the Backyard Restoration Garden.”
In addition to saving water and money, and supporting the local ecology, California native plants offer some additional benefits in landscaped areas. Their use can make a site look more relaxing because it reminds us of natural areas, but only if the garden is designed with an informal rather than a manicured “look.” California natives require comparatively little pruning and little to no fertilizer. They require even less water when fallen or removed debris (leaves, small twigs, etc.) is left in place or spread out as natural mulch, rather than being collected and removed. Native plants also usually require no pesticides because they have developed their own defenses against many pests and diseases. Avoiding pesticide use prevents killing beneficial insects and keeps toxins out of our waterways. All of these practices could reduce the time hired landscaping personnel and homeowners spend maintaining gardens.
Finally, readers may be interested in the position of California legislators on the drought and the use of California native plants. In July 2015 they approved a revised “California Model Water Efficient Landscape Ordinance.” It aims to increase water use efficiency, in part by limiting the percentage of landscapes that can be planted with high-water-use plants. The ordinance specifically mentions the “protection and preservation of native species and natural vegetation;” the “selection of water-conserving plants, trees, and turf species, especially local native plants;” and the “selection of plants based on local climate suitability.”
Increasing the use of native plants in our landscapes is something we can easily do if we plan carefully. It will help us save water, and can have the added benefit of improving the health of our local ecosystem. I encourage everyone to become involved in this effort.
This article first appeared in the Rossmoor News on September 02, 2015. Author: Bob Hass. Editor’s Note: the California Native Plant Society.website offers an excellent list of native plants specific to Walnut Creek.