The last advantage we will discuss is both conceptual and practical in nature and concerns questions of local identity. Have you noticed that nearly every green space in every new development built in San Diego county looks like the green spaces in other developments all over the state and beyond? One reason for this is that practically none of the plants used in these new developments come from San Diego, or even from California. Such uniformity of appearance would not be possible if the plants used were native to the area being developed. Local native plants could express a sense of local identity that is distinct from other regions.
Unfortunately, this same point applies to our individual residential yards. Since none of the plants normally used in our yards are natives, none reflect anything about our locale. In this light, there are three possible advantages that I believe could follow from promoting native gardens and the resulting move away from traditional exotic plants.
The first advantage is that the more native gardens there are, the more likely other people will learn to value the uniqueness of local natives and their ability to express a sense a local identity. The way things stand now even the idea that such an identity is worthy of expression though our gardens is a novel concept. Admittedly, it will take a lot more people hosting native gardens to achieve a critical mass that could effect a large scale change in people's values. Without some movement in this direction however, our region will continue to look increasingly like other areas all over the West where cookie cutter development and Home Depot horticulture have prevailed.
From a broader perspective, there are issues related to promoting our region's uniqueness that are much more important than the pleasure of flouting outmoded horticultural trends. A second advantage of increasing people's familiarity with our local plants is that this could also promote an appreciation of the uniqueness of the natural areas from which they come. This in turn could lead to increased support for the preservation of these areas.
San Diego is unique. As a county, it is famous for having more variety of plant species than any other county in the continental United States. For those who value the natural areas that surround us, it is an important question how to garner the public support needed to preserve them in the face of pressure for further development. The problem is real. One of the many of our local habitats, Coastal Sage Scrub, has been called the most endangered habitat in the world and it is getting smaller every day due to development and other causes of habitat destruction.
I believe familiarity with native plants could prove decisive in this area. It is an unfortunate state of affairs that most people in San Diegto clearly know more about exotic garden plants that come from other states and other countries than they do about the natives of their own locale. This state of affairs is clearly a result of the predominance of traditional exotic-based horticulture over many generations. It is not realistic to expect people to struggle to help preserve endangered natural areas if they don't know anything about what is out there. Thus, increasing familiarity with natives, through education and through daily exposure to native gardens, could have an indirect but lasting effect on the public valuation of our natural areas in a way that is not possible now.
A growth in awareness of our area's uniqueness could lead to a third, very practical advantage that would benefit the environment as a whole. A direct consequence of an increase in the use of local native plants is that there would be a resulting decrease in the use of the exotic garden plants that are invasive. Not all exotic garden plants are invasive, but those that are can take over local native plant communities. Over the years, by taking space and resources away from native plants, invasive plants have had widespread and sometimes devastating effects on our natural areas. In extreme examples this leads to type conversion, where the health of whole plant communities is so degraded that eventually nothing remains but a monoculture of invasive weeds. This represents the exact opposite of a valuation of uniqueness and local identity.
This process has been happening since the introduction of non-native grasses for raising cattle in the early days of settlement. More recent examples are invasives that have been used in residential gardens. One famous example is pampas grass, an ornamental plant from South America that, when it escapes from people's yards, can take over adjacent natural areas to the detriment of native flora and other residents of riparian habitats. Were we to learn to value the concept that each region should reflect its own character through its gardens, there would inevitably be less problems with invasives.
To me, it is a dynamic prospect that using local natives not only helps conserve resources but can also strengthen the image of San Diego as having its own identity, and that this in turn could help inspire people to preserve the natural environs outside of the garden domain. Of course, one downside of expressing individuality in this way is that planting a native garden goes against a strong current of traditional horticultural conditioning. That is, going native would seem to put one directly at odds with a blind, powerful force in the world that makes money by perpetrating and maintaining a dead-end and incredibly wasteful horticultural direction. Fortunately going native is not as scary as this sounds. All the drama one may feel associated with such a change in direction dissipates quite easily from the simple act of placing a young native plant in the earth and watching it grow. How refreshing that such a simple action can undo years of misdirection.