Northern California’s Foothill College

I’ll admit, I’m not a huge fan of bamboo, especially the kind that grows a foot a day and needs to be dug out with a tractor. But this week, I was pleasantly surprised to have my views suddenly upended. It all started with some aqua stems I spied growing in my sister-in-law’s garden.

A CALIFORNIA JAPANESE GARDEN

Nestled in the hills of Northern California, my sister-in-law’s garden was created by a Japanese landscape master. Like fine wine, it took shape over years, gradually achieving a balance of appearance and aroma. The zen-like retreat comprises a network of narrow earthen paths that weave through interesting foliage, sculpted branches and sweet-scented flowers. In January, the garden is awash with camellias.

Along one side of the garden there is a tall bamboo hedge whose arching foliage flutters softly overhead. Though beautiful to look at, it’s the running type that needs to be controlled aggressively all year. But new to the garden, tucked into a corner, was a species I’d never seen before. Smaller in size, it featured striking blue-green stems. According to my sister-in-law, it was of the clumping kind. 

My sister-in-law’s clumping, aqua blue bamboo

Clearly bamboo had more to offer than I had previously imagined.

THE FOOTHILL COLLEGE BAMBOO GARDEN

Following my visit, a 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 just below its Japanese Cultural Center. The aqua-stemmed bamboo had certainly piqued my interest. So, curious to see what other varieties I might discover, I agreed to go. 

Foothill College’s Japanese Cultural Center

Created in 1989, the Bamboo Garden at Foothill College showcases around 70 different bamboo varieties. Ranging in size from groundcovers to specimens over a hundred feet tall, the plants form a tapestry of airy leaf forms held aloft by bright-colored stems. The collection is for demonstration purposes, only, and includes many species that are not commonly found 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), a visit to the garden is a multi-layered experience. Similarly to my sister-in-law’s, narrow paths loop back and forth across the slope, offering close-up views of the many exotic species.

WHAT KIND OF PLANT IS BAMBOO?

Bamboo is classified as a woody perennial evergreen plant. In other words, its stems don’t die back in winter. Part of the grass family (Poaceae), it 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. However, there are a few species that 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. These unusual ‘trunks’ can range in size from 1 mm to 30 cm (approximately 12″) in diameter. Typically hollow, the culm segments begin and end with a solid joint called a node. A pair of rings protects each node, in a formation known as ‘swelling’.

Most of us are familiar with the typical culm shape. Ringed nodes alternate with smooth segments (called internodes) that vary in length, number and shape depending on the variety. As the plant grows, branches and leaves sprout from these nodes. And each new branch features 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, it’s on its side. Instead of branches and leaves, however, the plant produces roots and shoots at the nodes. Eventually the shoots burst through the surface to form more culms. This 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 a result, the plant tends 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

Generally, 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. Others bloom only sporadically. But, the majority of woody bamboos flower once every 20 to 120 years.

Sadly, most species die soon after flowering. Scientists hypothesize that this allows the new seedlings to reap all the benefits of water, sunshine and nutrients that might otherwise be consumed by the mother.

Bamboo flowers

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 believe 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 Foothill College site.

BLACK BAMBOO

Phyllostachys nigra or Black Bamboo was the first species to be planted at Foothill College. Growing to about 16 feet tall, its slender, jet-black culms add a refined look to the garden. Indeed, Nigra is one of the most popular ornamental bamboos in the world.

Although the species is generally not considered invasive, growers recommend containing it with some type of rhizome barrier just in case.

Phyllostachys nigra

WHITE BAMBOO

Bambusa chungii, also known as White 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 species’ dense form make it a great privacy hedge. And its clumping habit makes it easy to maintain as a specimen. There is a smaller variety called ‘Barbie.’

Bambus chungii

CHINESE TEMPLE BAMBOO

Sinobambusa tootsik ‘Albostriata’, also known as Variegated Chinese Temple Bamboo, is a running type 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 with a rhizome barrier.

Sinobambusa tootsik ‘Albostriata’

CHUSQUEA MIMOSA

Native to southern Brazil, Chusquea mimosa is a clumping bamboo with arching stems. In my view, it resembles a Japanese maple with its clouds of small, lacy leaves. The species generally prefers part shade, but when grown in full sun its culms turn a shiny, dark red. It grows to about 45 feet tall.

Chusquea mimosa

PSEUDOSASA OWATERII

Native to Japan, Pseudosasa owaterii is one of the smallest known running bamboos. Reaching a maximum height of around 24″, it makes a delicate-looking groundcover.

Pseudosasa awatarii

MEXICAN WEEPING BAMBOO

Mexican Weeping Bamboo, Otatea acuminata aztecorum, 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

GIANT TIMBER BAMBOO

Giant Timber Bamboo, Bambusa oldhamii 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 neighbors. Even better, it has a clumping habit and is non-invasive, making it a low maintenance choice for the garden.

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. (This is also the source of my sister-in-law’s aqua cultivar.)  Happy planting!