Native plants for the California garden
I had the great pleasure of attending a California Native Plant Society talk by Arvind Kumar last night entitled Biodiversity, native plants and you: protect the environment, conserve water & save money. The presentation was full of wonderful information, and I want to share with you a few high points that spoke to me.Having traveled throughout California from the desert east of San Diego to Lassen Volcanic Park to the foothills of Mount Whitney and the subalpine meadows of the Sierra Nevada, I have seen some of the state’s biological diversity. In his talk, Kumar mentioned that California is a biological diversity hotspot, containing more species richness than all the other US states combined. This was a staggering statement to ponder. He also stated that as we transport water away from the source in the Sierra Nevada and Central Valley, we loose biodiversity in these locations. An unfortunate consequence of this water shuffle is that the end user has very little associated cost or awareness of what’s lost. One statistic from the talk is that 57% of water goes to landscaping with 9% going to overwatering landscapes, with the remaining 34% for home use. And, many of the plants we put in our gardens, because they are best suited to the soil, climate and insect relationships of distant locales, actually need significantly more water, fertilizer and pesticides than native plants do. By replacing our thirsty gardens with climate-adapted, ecology supporting native plants, we can actually begin to restore balance.
Another fun fact from the talk is that plants are at the bottom of the food chain — eaten by everything else. Insects are next in line. Some insects are more general as to their herbivorous needs, and some are more specific, requiring only one plant species or environment in which to survive. Case in point is that sometimes these plants or conditions are lost, and so are the insects that depend on them. As I’ve learned from my time in the field surveying butterflies, if the larval food plant is present in it’s natural environment, and has been there for some time, it is almost a guarantee that the butterfly will also be present. The more we can support our intact natural areas and systems, yes even within San Francisco City limits, the less of these vital relationships will be lost. Kumar sited the book Bringing Nature Home when he stated that native plants produce over four times more insect biomass than non-native plants.
On my way to the talk, I made this photo (below), which happens to be a beautiful illustration for the talk. This San Francisco native plant sidewalk garden contains globe gilia, hummingbird sage, California poppy, red elderberry, dune strawberry, clarkia, and phacelia — all thriving after the winter rains. Kumar reinforced something that I always share with my clients: California native plants experience dormancy in summer. Now, in springtime the natives are beginning to show a full display of robust color, delicious scents and exquisite texture and growth habits. I hope you can get outside and enjoy.