Bamboos at San Francisco Botanical Garden, part 1

Yesterday I had the opportunity to spend some time at San Francisco Botanical Garden. This 55-acre sanctuary in the heart of Golden Gate Park is a great place to get away from the hustle and bustle of the city and yet it is only minutes from the Japanese Tea Garden, the de Young Museum and the California Academy of Sciences. You can park your car in the Music Concourse parking garage and easily walk to all these places.

San Francisco Botanical Garden has 8,000 plants varieties from around the world, grouped into a dozen or so collections, including the Mesoamerican Cloud Forest, the Ancient Plant Garden, the Temperate Asia Garden and one of my favorites, the Moon-Viewing Garden with its gazing pond and Japanese lanterns.

While San Francisco Botanical Garden doesn’t specialize in bamboo per se, there are several dozen bamboo species scattered across the various collections. I enjoy scouting for bamboo (or other plants I might be interested in) in public gardens because they typically have mature specimens. That gives me a good idea of what a given species looks like once it is fully grown. In a sense, this is like test driving a car because it allows you to quickly determine whether that bamboo you fell in love with in a book will actually fit into your yard.

Following are some of the clumping bamboos I saw at San Francisco Botanical Garden. The running bamboos I encountered are described in a separate post.

Chusquea (clumping)

Chusquea is a large genus of clumping bamboos from Central and South America. According to the literature, there are as many as 200 different species, some of which haven’t even been described yet. Only a dozen are currently available in the U.S.

Many Chusquea species are native to tropical and subtropical regions and tolerate no frost; others, such as Chusquea culeou and Chusquea gigantea, grow at higher elevations in the foothills of the Andes and are hardy to 0°F.

Unlike most other bamboos, chusqueas have solid culms. They develop many branches at each node which gives them a unique feather-duster look. With their small leaves and arching habit, chusqueas are highly ornamental. However, their intolerance of heat—especially warm nights and warm soil—restricts their use to coastal regions like the San Francisco Bay Area. The Sacramento area is too hot for chusqueas; while they do survive here, they look ratty much of the year. In the fall I planted a Chusquea gigantea at my in-laws’ property in the Northern California mountains; I’m hoping that in spite of occasional 90°F days, it will thrive there. 

While chusqueas are technically clumping bamboos, many of them have long rhizome necks, which means that new culms can come up at quite a distance from the mother plant, sometimes as much as a foot away. This behavior makes them unsuitable for really small yards.

While San Francisco Botanical Garden, according to the Plant Finder on their website, has six chusquea species I only found one: Chusquea sulcata.

Chusquea sulcata. With its thin leaves and whorls of branches at each culm node, this species typifies the chusquea look. It’s a tropical species, hardy only to 28°F.

 

Himalayacalamus (clumping)

Himalayacalamus is a genus of clumping bamboos native to the lower elevations of the Himalayas. Himalayacalamus species are not very cold-hardy (they sustain damage below 20°F or so) but at the same time they don’t tolerate high summer temperatures either, especially in conjunction with high humidity and nighttime temperatures above 70°F. These requirements make them ideally suited for the San Francisco Bay Area. Here they thrive as can be seen from the photos below.

We have a Himalayacalamus hookerianus ‘Teague’s Blue’ in a shady spot in our back yard, and while it has been a slow grower, it does look very healthy in spite of our high summer temperatures. This may sound like a contradiction of the cultural requirements I just mentioned, but our humidity is very low in the summer, and even on a 95°F degree day, nighttime temperatures typically drop into the low 60s thanks to the Delta Breeze coming in from the San Joaquin-Sacramento River Delta to the south of us.

The key to growing Himalayacalamus in the Sacramento Valley is to provide a location that is in the shade most of the time—but definitely in the afternoon—and that gives protection from high winds that would otherwise desiccate the foliage. A spot under a mature tree would work well.

Himalayacalamus hookerianus, commonly known as “blue bamboo”. Its adult height is in the 15-20 ft. range.

New culms of blue bamboo start out whitish blue and age to a burnished gold color. I find this contrast to be strikingly beautiful.

Mature clump of Himalayacalamus falconeri ‘Damarapa’, commonly known as candy-cane bamboo for the vivid colors on new culms: green stripes against reds, purples and yellows. Like blue bamboo, it reaches an adult height of approx. 20 ft..

 Himalayacalamus falconeri ‘Damarapa’, close-up of the same clump. Older culms age to a burnished yellow, typical of most Himalayacalamus species.

Himalayacalamus asper, also known as Tibetan princess bamboo. This species sports very small and delicate-looking leaves. As you can see in the photo above, the culms bend under the weight of the leaves, resulting in a beautiful willow shape but requiring more space than the other Himalayacalamus species.

 

Thamnocalamus (clumping)

Thamnocalamus is a genus of clumping bamboos native to the Himalayas and—in a quirky twist of evolution—South Africa. San Francisco Botanical Garden doesn’t have any of the Himalayan species, but they do have the South African one, Thamnocalamus tessellatus, or “bergbamboes” as it is called in South Africa.

Thamnocalamus tessellatus covers vast stretches of land in its native South Africa. It is considered one of the most drought-tolerant species while also hardy to 0°F. As you can see in the photo above, it forms an impressive clump under ideal conditions. However, closer up, it isn’t the most refined species owing to culm and branch sheaths that remain attached for several seasons and end up looking tattered.

Side note: While Africa isn’t the first place that comes to mind when we think of bamboos, there are in fact several species native to the African continent, in particular sub-Saharan Africa (genus Oxytenanthera), South Africa (Thamnocalamus tessellatus) and East Africa (Yushania alpinia). In addition, the cultivation of non-native bamboos is being explored in countries like Kenya for their commercial potential; check out this interesting article.

To read about running bamboos at San Francisco Botanical Gardens, click here.