Lets Do This!

We live in Southern California. Few places possess the biological richness of our home. More species live here in San Diego County than just about anywhere in the United States. We are so lucky! One way we can help protect the large number of unique species is to landscape our homes with native plants. Think about it. Millions of years have honed the relationships between the endemic flora and fauna to the perfection that exists today.

But look around - what plants do you commonly see in your community? That's right, just a small number of exotic plant species from the big box store exist in nearly everyone's landscapes. The nectar from that tropical hibiscus or rosemary is not nearly as nutritious for local hummingbirds and bees as is the nectar produced by natively occurring Salvia mellifera or Phacelia campanularia. Local plants offer optimal nutrition for local fauna. Not only that, but exotic species are often poisonous to our fauna. For example, Nandina berries, although eaten by local birds, may kill them if consumed to excess. An opposite example of this is between our native Aesculus californica and honeybees--an exclusive diet of pollen and nectar from this plant will kill or disfigure the progeny of the honeybee. Honeybees are not from San Diego they originated in Europe and did not evolve to partake of our native Bottlebrush. Lets give our local fauna the local plants that offer them the chance to thrive.

Salvia mellifera

But, you say, my Pyracantha has fruit that the birds relish. That may be true, but recent studies show that not only is the nutrition superior in local plants, but the phenology or timing of the plants makes all the difference to the reproductive success of the creatures that evolved to eat the plants. Meaning that, even though a species of bird will consume fruit from non-native plant species their reproductive fitness is decreased just enough to negatively affect the birth rate. Both the timing of the crop and the nutrition of non-natives are inferior to the native species.

Phacelia campanularia

So we have the excellent nutrition native plants provide, plus native endemic plants are drought tolerant. In San Diego we typically get less than a foot of rain a year, and all of it in the months of winter and spring. Native plants have evolved adaptations to be able to survive on little water in the colder months and no water in the summer. Better yet, using locally sourced native plants fine tunes the drought tolerance to the same conditions as exist in your garden at home.

Aesculus californica

The biological richness of San Diego County means we have a large number of species of plants to chose from. And the great thing is these plants are gorgeous and occur nowhere else in the world! So lets do this! Lets plant natives, lets bring back the waning populations of birds, butterflies, and bees. We have the power to keep San Diego biologically rich and diverse.