Carpenteria in California
In California, June can be a tale of two seasons where the heat of spring meets the cool of summer. In the lower elevations during June, fleshy spring blooms give way to longer and warmer days. The transition of this shoulder season becomes particularly apparent in the foothills of the Sierra Nevada. Days become hot but the nights remain cool and green grasses begin to take on a tinge of brown, laying forth that quintessential California-dry scene. In June, water begins to become scarce as summer dry takes root.
The climate of California was not always as it is today. Millions of years ago the climate of California was wetter year-round and summer rain was routine. The middle and late Miocene flora of California reflected this steady supply of available moisture.
Over millennia, a cold water current eventually developed off the coast of California and summer rain evolved to become a thing of the past. All the while, the flora of California was being etched out.
In the foothills just northeast of Fresno, the anomaly that is the California flora becomes evident. In a relatively small swath of terrain lives a California native beloved by many California native gardens: Carpenteria californica (Bush Anemone).
In the wild, Carpenteria californica is a rare and endangered plant. It grows in only a handful of locations between the watersheds of the San Joaquin River and the South Fork of the Kings River.
Carpenteria californica was one of the first California native plants I ever specified. I was a young, inexperienced landscape architect working in the Bay Area and I had recently taken an interest in California natives.
I decided to throw it into the plant palette for a techy building renovation project I was working on. From what I had read, it seemed like a safe bet. A relatively easy to grow and forgiving native that flowers regularly and looks decent year-round – a definite pre-requisite for any plant that had to stand the litmus test of startup developers and fashion forward architects. Carpenteria californica survived that litmus test just fine.
It was not long after that project that I walked away from development-based landscape architecture. But Bush Anemone has remained on many plant palettes I continue to develop.
Bush Anemone is a very popular California native. It’s safe to say that many more Bush Anemone’s survive in gardens and throughout the horticultural trade than exist in the wild. Its popularity within cultivation lies in the fact that it is a very forgiving shrub. It grows well in shade but can tolerate a fair amount of sun. It can take regular water but can also tolerate rather dry (if not very dry) conditions. And it blooms profusely. The fact that it remains so popular in cultivation is no surprise.
What is a surprise, to me anyway, is that so very few of them remain in the wild. For a plant so versatile in gardens, naïve assumptions would have me guess it fairs well within its native range. But that is the anomaly that is the California flora.
Bush Anemone is a paleoendemic shrub that was historically more abundant long ago, when the climate of California included summer rain. As summer rain disappeared and California transitioned to a warm and dry climate regime, the range of Bush Anemone contracted. Today, the shrub clings to a handful of creeks and drainage areas within the central Sierra Nevada foothills.
What seems to allow Bush Anemone to hold onto existence may also be what allows it to thrive in so many gardens: Versatility. In the central Sierra Nevada foothills northeast of Fresno, where sustained summer drought endures, Bush Anemone undergoes a significant change. During the late summer months, when water is nil, the plant becomes severely dehydrated and takes on a tired and raggedy look. So bad that a casual observer may presume it’s dead. But not soon after the rains return, so too do the leaves. Bush Anemone responds very well to the return of moisture. Consequently, it generally has the ability to sustain the range of gardening mishaps, from overwatering to total neglect.
The tolerances of Bush Anemone make it a very easy plant to grow and a selected candidate in many gardens. With fleshy, glossy green leaves and clusters of large showy white flowers from May to July, it easily shines and impresses. That said, it does also have the ability to seemingly turn on you. I have had several clients call me to suggest that it had suddenly died, after being one of their garden stars. These comments come from the tired and raggedy look it assumes when its fleshy leaves brown out, as if attacked by a pest or viral infection. This assumed die back is the result of its impressive genetic fitness to withstand that hottest and driest time of year. And while the look is not desired, it can at least be a good sign of a healthy and established plant that will return to continually put forth rich growth and abundant blooms. Better yet, the curled leaves and overall tired look has an easy remedy.
From my experience, I have learned that keeping Bush Anemone small and compact allows it to look its best. I believe Bush Anemone is best when it’s allowed to grow no taller than 5’ or 6’ tall. When it grows taller than 5’ or 6’, it starts to reveal is less attractive side. Bush Anemone channels its growth into the canopy as it sheds much of its lower leaves. As it grows taller, the exposed underside becomes a mix of twiggy branches and desiccated leaves. By incrementally pinching the plant just after flowering, the size and compactness can be better maintained. This can help obscure the wilting leaves at the base of the plant. Likewise, hand removing curled and dried leaves will greatly improve the look. The dried leaves are not easily plucked off the plant, but determination will yield good results.
Bush Anemone is also one of those plants that greatly appreciates some summer water. While it has a phenomenal ability to sustain the summer dry conditions of California today, it also hails from a time when California received summer rain. While the dogma of growing California native plants generally implies that summer water is unnecessary, if not detrimental, Bush Anemone can be a bit of an exception. Bush Anemone has the impressive ability to respond to the return of rain, which also means it can respond well to incremental summer watering. How much will depend on the garden’s location and the plant’s situation within each garden. In almost all cases, summer watering is best when applied by hand so as to better control the application and assure other nearby plants are not overwatered. Use care to make sure warm season watering does not lead to excessive soil moisture - apply only enough to refresh the plant and dampen the soil around the root ball, kind of like a summer rain shower would do.
When siting Bush Anemone in the garden, think of those seasonal creeks and drainages during mid June. Find a spot in the garden where the soil will remain cool and somewhat moist while the ambient air is still hot and dry. My experience has found that Bush Anemone does best when it’s in shade during the latter half of summer. That said, I have planted it in full year-round shade in Riverside County and in full south facing sun along the coast. It performed well in both instances. However, what I have noticed is when it's in full sun, even on the coast, the leaves will brown out. They take on a sickly look but not enough to allow them to drop, making it harder to maintain its better appearance. By placing the plant where it can embrace shade, especially during the hotter months, the leaves will better maintain that glossy green.
Don’t be afraid to work Bush Anemone into a thick stand of planting. It behaves well and embraces a mixture of plantings. Just be sure to locate it alongside plants that may also tolerate some summer watering, so that you may maintain a more attractive appearance. Or, let it desiccate. Savor the warm and dry that is summer in California and let Bush Anemone embrace its supreme ability to endure amidst all odds.
Additional Reading
Delbert Wiens, Thomas Worsley, Reproductive failure: a new paradigm for extinction, Biological Journal of the Linnean Society, Volume 119, Issue 4, December 2016, Pages 1096–1102, https://doi.org/10.1111/bij.12843