Volume 56, Number 1 - Winter 2010

 

By Joan Pont, MD

Growing up in Southern California, as I did, means spending an inordinate amount of time in the back of a car going from one activity to another. Peeking over the bottom sill of the car window, one sees interminable stretches of oleander lining the median strip of countless freeways. The plants seem to soak up all the toxic emissions jettisoned from the cars–and to grow stronger with exposure. I developed a Pavlovian response to oleander, associating the plant with exhaustive car rides. To this day, I have a visceral aversion to freeway plants. 

When we purchased a 1960s-era house in Mill Valley in 1983, the garden was vintage freeway median strip. The plants could have survived nuclear war. These are species that never really die, so they are always labeled “low maintenance.” As a field guide expert on the plants of median strips, I can assure you that all species were well represented: the aforementioned oleander, along with eucalyptus, ivy and agapanthus. 

My apartment-reared husband was aghast that our first expenditure in our first house went to Randy, from Artistry in Trees. He used no artistry at my house; he simply chain-sawed everything to the ground and was glad to do so. 

Why would that be? Why should perfectly happy living plants be extirpated and chipped into oblivion? Let me peel back the layers a few hundred years and see if you can understand my inflexibility in insisting that alien plants be removed, forcibly if necessary.

We moved to Marin County shortly after the severe and prolonged drought of the late 1970s. Many new friends and neighbors were still bemoaning the loss of their lawns and gardens because they had had to stop watering. But not everything was desiccated and withered. I looked up at the slopes of Mount Tamalpais and saw that the manzanitas were clearly still green, although they weren’t putting out any new leaves. Fitting in between those sturdy and graceful shrubs were the chamise which, incredibly, were actually sprouting new leaves. On other slopes of Mt. Tam, less steep, less south-facing, and with more retention of scant winter water, were stately oaks, Douglas firs, redwoods, and hundreds of species of understory plants. All were a verdant green despite the lack of rain.

Inspired by Mt. Tam, I decided to plant a native garden, using only native plants. Of course, I knew absolutely nothing about them at the time. I didn’t even know that the little round scratchy shrub near the back gate was a young oak tree. It was unceremoniously bashed each time the gate opened and closed. Once I realized what it was, I moved the gate, not the oak, which is now a sizable tree, branching out its beautiful twisted canopy. In 300 years, it will be really majestic. 

Flipping through Pacific Horticulture magazine, I saw an ad for the California Native Plant Society (CNPS). I mailed in my $35 membership fee right away, and I soon began receiving a monthly newsletter, complete with listings for outings and field trips. 

I vividly remember my first field trip. Knowing no one, I drove out to Nicasio Reservoir one spring day to see what CNPS was all about. Twenty people, wielding hand lenses and field guides, were practically crawling on their stomachs identifying plants with binary nomenclature. Since they spoke only botanical Latin, I had no idea what they were talking about. “I’m shocked to see Streptanthus glandulosus so early in the season,” one woman said. I was flummoxed. They kindly threw me a few bones, then set off in search of rare, beautiful and vanishing species.

California has about 6,000 species of native plants, and Marin County hosts over 1,000 of them. It has always fascinated me that a particular plant can be found over a vast range, but one inch out of its comfort zone and the plant will refuse to grow. Consider the sharp demarcations on the sides of hills. A coast live oak atop a hill produces thousands of acorns annually. Most end up as food for birds, insects and mammals, but those that drop to the ground and roll along the northern face of the hill have a decent chance of establishing themselves. But move just one foot over the edge of a hill to the south exposure, and there are no more oaks, even though acorns flow down that side as well.

After the field trip, my first challenge was to find a plant suitable for my steep south-facing garden. What little true topsoil there was had been unceremoniously scraped off to produce the small level portion that constituted our back yard and house. Consequently, I had to find a plant that would live happily on six inches of clay masquerading as topsoil. 

Back in 1983, Internet searches for suitable plants were far in the future. Instead I used the Sunset Western Garden Book, which includes lists and descriptions of plants for various ecological niches. I combed the lists for a ground cover that would also be drought-resistant, protect against erosion, and native to California. All that flipping back and fourth through the lists led me to conclude that the perfect plant was Arctostaphylos uva-ursi, a low-growing manzanita. 

I hurriedly bought and planted a dozen or so during a late March rain, and they have been happily and slowly growing ever since. I am so stingy on my fertilizing that I have little trimming to do. Weeds tend to prefer my neighbors’ yards more than mine because theirs are steeped in Miracle-Gro cascading into the bay. Here’s a little lazy gardening secret to minimize trimming and weeding: go light on the watering and fertilizing; just use them to get the plant established. 

The more I learned from field trips with the CNPS, the more I realized that California, AKA the California Floristic Province, has lots of plant species. I picked the major theme, and sequentially narrowed down the range of plants from which to choose. Using California natives was no longer sufficient; I now preferred plants native to Marin County. Eventually, I moved toward a true restoration garden by choosing only plants that would have been here since the last Ice Age. 

There was probably a large and fairly stable constellation of plants growing on our hillside for thousands of years. Any plants that had remained through ranching and subdivisions and previous owner’s attempts at gardening were treasured. Around our yard, I came across Nassella pulchra (purple needlegrass), Wyethia angustifolia (native sunflower and food source for Miwoks), and Sidalcea malvaeflora (checkerbloom).

I started out buying plants and seeds from nurseries. Later, I tried my hand at propagation, another skill set in my quest for a truly native garden. Truth be told, I did not remove my non-Marin plants, just kept narrowing my choices for later additions. 

As an internist, I remember diseases and differential diagnoses; but those names and facts I learned at a younger age, while in medical school. Deeply imprinted and reinforced, they are now my first language. Learning botanical Latin was considerably more difficult. I had to look up names over and over. To help me remember what was what, I bought a bulletin board and drew an outline of the house and garden, along with all the paths and planting areas on it. Whenever I introduced a new species into the garden, I would write the Latin, family and common names on an index card and stick it to the board in the corresponding location.

My son Sean is my best IT consultant. One day, I returned home from one of my favorite nurseries (Mostly Native, in Tomales) and started cutting out and labeling index cards. Sean piped up, “Mom, this will not do. Let me see if I can come up with a mapping program.” Using standard PowerPoint, he took photos of the four sides of the yard and scanned in an architectural drawing of the house and garden. He then added translucent “action buttons” to each image that transported the user to a page dedicated to the plant growing in that location. 

One could now “walk” around the digital garden and click on plants for a full description. For several months, I created one slide per species. Much more information can be placed on a PowerPoint slide than an index card. For example, I found a quote from Shakespeare about the twinberry honeysuckle (“So doth the woodbine the sweet honeysuckle gently entwist”) and a quote from Captain Smith of Pocahontas fame regarding the dogbane, an important fiber plant for rope making. The digital garden now has more than 180 slides. 

During the past 26 years of establishing the garden, I have often thought about my favorite quote from a traditional English gardening book: “Imagine, they managed to established a decent garden in only one generation.” I like to think of the plant choices I made over the years in concentrically smaller and smaller circles. First, I would choose a plant appropriate to that site in the garden if it was native to California. Then I got pickier, found better native plant nurseries and native plant sales and chose plants found naturally in Marin County. Finally I tried my hand at propagation and chose plants from our local hillside and watershed. I never removed a plant from the wild. Seeds collected and successfully propagated produce orders of magnitudes more seeds, with increased biodiversity.

That may seem like a contradictory statement: choosing plants from a limited location and increasing biodiversity. What we are really doing is preserving what little biodiversity still exists. When a non-native plant such as Scotch broom is introduced on purpose or by accident, it generally does not come with its complete ecosystem. No koalas to nibble on the new growth eucalyptus. No European pests to manage the annual grasses. More problems happen when an exotic animal is introduced to control the species. The animals could take two bites of their original food source, but find something here, rare and native and more to their liking, and the attempt at controlling the plant backfires. The end result is that a few non-native plants grow completely out of control and crowd out native plant species. Building sanctuaries for native plants is thus essential to their survival. 

To the uninitiated, a flowering hillside of Scotch broom may be an impressive sight. But one has to remember that there are 12 months in the year, not one. A hillside that doesn’t bloom for the remaining 11 months will be bereft of pollen and nectar for the invertebrates that are pivotal for a sustained ecosystem. A California hillside before the European invasion would have been home to 100 to 200 species, not just one. In a diverse garden, on any day of the year, a new flowering plant should appear and mature. 

By the way, it is important not to “deadhead” (prune) the dead flowers. Flowers are just one stage in the sexual reproduction of plants. After flowers are pollinated, seeds mature. In each seed lies the embryonic plant, plus plenty of food to sustain the plant until it can generate its own energy through photosynthesis. Almost all the seeds are eaten by birds and other animals, with only a few left for the next generation. By not removing the withered blossoms, one creates hundreds of bird feeders in the form of dried seed pods. Each brown dried flower, maligned by your neighbors as representing lazy gardening practices, is beneficial to the garden. Add a little water source and you have birds and bees galore.

That is my gardening tale. I have learned so much, appreciated the tremendous evanescent beauty of a bloom or stately tree, developed a sore back from digging, and enjoyed every minute. Please contact me for a complete plant list or with any questions you might have.

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Dr. Pont, an avid gardener, is an internist at Kaiser San Rafael.