The Bamboo Garden at Northern California’s Foothill College
I’ll admit, I’m not a huge fan of bamboo, especially the kind whose roots advance a foot a day and need to be dug out with a crane. But, I was pleasantly surprised this week to have my views on the plant suddenly upended. It all started with a spectacular variety featuring aqua stems I spied growing in my sister-in-law’s garden.
Nestled in the hills of Northern California, my sister-in-law’s garden was created by a Japanese landscape master. Like good wine, it took shape over many years, gradually achieving a fine balance of different sensations and aromas. The well-choreographed space takes its design cues from nature; a network of narrow earthen paths weaves the visitor through diverse plants featuring interesting foliage, sculpted branches and sweet-scented blooms. In January, the garden is awash with flowering camellias.
Along one side of the garden there is a long stretch of giant bamboo whose arching, fluffy green foliage softly flutters in the sky overhead. It’s the kind that likes to spread, however, which dissuades gardeners like me from planting it. But new this year, tucked into a quiet corner at the far end of the screen was a species I had never encountered; a medium sized cultivar with striking blue-green stems. Best of all, it was of the clumping variety.
My sister-in-law’s clumping, aqua blue bamboo
Clearly bamboo had more to offer than I had previously imagined.
Following my visit, my girlfriend suggested we tour a bamboo garden near her home in California’s Los Altos Hills. Located on the campus of Foothill College, the two-acre garden covers a slope below the school’s Japanese Cultural Center. The aqua-stemmed bamboo had stirred my interest – I agreed to go, curious to see what other interesting varieties I might discover.
Foothill College’s Japanese Cultural Center
The Bamboo Garden at Foothill College
The Bamboo Garden at Foothill College is first and foremost a demonstration garden. Created in 1989, it today showcases around 70 different bamboo varieties. Ranging in size from foot-high groundcovers to giant specimens over a hundred feet tall, the exotic plants are a tapestry of airy leaf forms held aloft by multitudes of bright-colored stems. Many of the bamboos are cultivars not commonly seen in the United States.
Pathway through Foothill College Bamboo Garden
Aside from its educational value (the different varieties are being studied for their adaptability to the San Francisco area climate), a walk through the garden is a multi-layered experience. As in my sister-in-law’s garden, the narrow paths loop the visitor back and forth across the slope, offering close-up views of the many exotic species.
What kind of plant is bamboo?
Bamboo, (Bambusodae) is classified as a perennial grass plant that is woody – meaning its stems do not die back every winter but instead increase in size with each growing season. Part of the grass family, Poaceae, bamboo includes over 91 genera and around 1400 known species. Woody bamboo is most commonly found in tropical to subtropical or moderate climates, with most species hailing from East and Southeast Asia. A few species, however, are native to the southern United States.
Bamboo is one of the fasted growing plants in the world.
Giant timber bamboo
Anatomy of a culm
One of the most striking things about bamboo is its cylindrical stems, called culms, which can range in size from 1 mm to 30 cm (approximately 12″) in diameter. Typically hollow, the culm segments each begin and end with a solid joint called a node. Each node is protected by a pair of rings (or ‘swelling’).
Most of us are familiar with the typical bamboo wood shape – ringed nodes alternate with smooth segments, called internodes, that vary in length, number and shape depending on the variety. Branches and leaves, which sprout from the nodes, have culm-like nodes and internodes, too.
Culms of Phyllostachys vivax, one of the largest bamboos growing in the Pacific Northwest
Underground, the bamboo root system also resembles a culm, but in this case on its side – that is the roots grow horizontally from a rhizome with nodes and internodes. Instead of branches and leaves, however, the rhizome produces roots and shoots at the nodes. These eventually burst through the surface to form more culms. This is what is called running bamboo.
Indocalamus longiauritus, a small-sized running bamboo native to China
Bamboo is shallow-rooted with most of its growth taking place between late summer and early fall. Typically, most root systems do not extend further than 20 inches below the soil surface.
The difference between running and clumping bamboo
Unlike running bamboo, which grows horizontally, clumping bamboo has rhizomes that grow upwards before developing into a new culm. As new roots and shoots develop, they emerge vertically rather than horizontally. This causes the plant to expand more slowly around the perimeter, giving it a ‘clumping’ habit.
Bambusa toldoides, also known as Punting Pole Bamboo, is a tall, clumping variety
Some species take a century to flower
Bamboos aren’t known for their flowers; yet flowering plays an essential role in perpetuating each species. Some varieties flower continuously year after year in one to two month intervals, while others flower sporadically. But, the majority of woody bamboos flower once every 20 to 120 years.
Sadly, most species die soon after flowering. Scientists surmise that this allows the new seedlings to reap all the benefits of water, sunshine and nutrients that might otherwise be consumed by the mother.
HERE’S A REALLY COOL FACT: Many bamboo species exhibit what is called gregarious flowering, meaning that when they flower, they do so at the same time all over the world. And they bloom simultaneously, regardless of climate or geography! While the reason for this timed flowering is unknown, some scientists surmise that bamboo cells may contain a genetic alarm clock that wakes them up at certain time periods that are predetermined.
Seven bamboos that stand out from the crowd
Intrigued by the possibilities? I am. Here are some beautiful bamboo species I spied at the Foothill College Bamboo Garden. For a complete list of species that can be found in the Foothill Garden, click here for the Bamboo Garden at Foothill College site.
Phyllostachys nigra, also known as Black Bamboo, was the first species to be planted in the Foothill College Bamboo Garden. Growing to about 16 feet tall, its slender, jet-black culms add a refined look to the garden. Nigra is one of the most popular ornamental bamboos in the world.
The species is not generally invasive, although it’s recommended to contain it with some type of rhizome barrier just in case.
Bambusa chungii, also known as White Bamboo or Tropical Blue Bamboo, makes a stunning statement perched on the Foothill Garden’s slope. The variety tops out at around 40 feet tall with culms measuring around two inches. The dense form of Bambusa chungii makes it a great privacy hedge. And its clumping habit means it can also be easily maintained as a specimen. A smaller version is called ‘Barbie.’
Sinobambusa tootsik ‘Albostriata’ also known as Variegated Chinese Temple Bamboo, is a running form that can be aggressive. However, its yellow and white striped leaves can do a lot to brighten a dark corner. Albostriata grows 15 to 20 feet tall with 1-inch diameter culms. It can be controlled by a rhizome barrier.
Sinobambusa tootsik ‘Albostriata’
Chusquea mimosa, a clumping bamboo, calls to mind a Japanese maple with its clouds of small, lacy leaves and slender, arching culms. It prefers part shade, but when grown in sun will produce culms that turn a shiny, dark red. It grows to about 45 feet high.
Pseudosasa awatarii, native to Japan, is one of the smallest known running bamboos. Reaching a maximum height of around 24″, it makes a delicate-looking groundcover.
Otatea acuminata aztecorum (or Mexican Weeping Bamboo), is a relatively rare species featuring very narrow leaves and a weeping form. A clumping variety, it is fast growing, eventually reaching a height of 12 to 15 feet.
Otatea acuminata aztecorum
Bambusa oldhamii (or Giant Timber Bamboo) is the most commonly grown species in the United States. Its dense evergreen foliage and impressive height (sometimes reaching 65 feet or more) make it a great choice for screening out your neighbor. Even better, it has a clumping habit and is non-invasive, making it a low maintenance choice for the homeowner.
Bambusa oldhamii is the most commonly grown species in the U.S.
Want to learn more? Check out Bamboo Botanicals’ information-packed site to see what cultivars might be suitable for your area. (Bamboo Botanicals is also the source of my sister-in-law’s aqua cultivar.) Happy planting!