Phyllostachys nigra   "Black Bamboo"   

     Black Bamboo is the oldest and most popular bamboo cultivated in the United States, first introduced in 1827. It has many unique characteristics. Individual culms go through a transformation in their first and second year providing bold, contrasting colors.   Small, light green leaves radiate from the culms with airy, feather-like arrangement.
     Beginning as new shoots emerging from the ground in April or May, they are covered by light burgundy colored culm sheaths, a specialized "leaf" designed to protect the tender new shoot (see photo below). By June or July they have reached their maximum height which is determined by the size and age of the grove. For example, a Phyllostachys that is 25 feet tall with two dozen culms,  produces many new shoots that spear out of the ground in April and grow to 30 feet by June; over three feet per week, or over four inches every day. It is an amazing sight to behold.
     When finished pushing toward the sky,  branches unfold from each node, shucking the culm sheaths and revealing a bright green culm. As the Summer progresses into Fall, the green culms begin to develop brown mottling concentrated at the nodes, especially near the base. By Winter the entire culm is speckled with fine black spots, usually dense enough toward the base to be solid brownish black. 
     The subject of many of these photos are culms exactly a year old which have completed the color transformation in a remarkably short time; consistently black from top to bottom.  This is unusual as there are many variations of P. nigra which take two to three years to finally achieve the same color. Some, such as P. nigra 'Punctata' or 'Muchisasa', retain brown mottling and never become  solid black. P. nigra 'Bory' has a unique brown mottling that looks similar to tree bark, though smooth and glossy with layered depth. P. nigra 'Hale' is  recognized as the darkest and quickest to change color. Our variety of Black Bamboo does not originate from the 'Hale' stock, though comparing the two side by side reveals they have similar qualities. We like to say ours is even darker and have taken to calling it P. nigra 'Ebony'.
     P. nigra 'Henon' is thought to be the original species from which all the color variations diverged. It is larger than Black and has identical foliage but doesn't ever turn dark, instead the culms age to a greenish-grey hence the common name: "Giant Grey Bamboo"
     In truth, many of the subtle P. nigra color variations are likely minor differences influenced by their local environment.  A legendary specimen of Black Bamboo in Folsom, California is rumored to have grown 60 feet tall with 3.5 inch diameter culms (it has been given the cultivar name 'Diakokuchiku'). The climate in Folsom is close to ideal with mild winters, hot summers, and a long growing season. A division from this plant may not produce anything so extraordinary if grown, for example, in coastal Oregon with our cooler summers and cloudy weather. 
    We have grown P. nigra just barely 35 feet tall in Oregon and have yet to find a specimen exceeding that height.  Unfortunately, many groves of Black that we encounter are obviously not well cared for: poor soil, not enough sun light, lack of water in the Summer, and a growing area that is too small and/or depleted of nutrients.  Any of these factors can lead to typical symptoms: small, weepy culms growing in dense clusters, stressed and yellowing leaves, many dry and brittle culms, especially in the center of the grove, with an average height of only 15 feet.
    Black Bamboo needs a rich layer of topsoil, 4-6 inches in depth. Bark mulch with compost or horse manure makes an excellent top layer through which the rhizomes can spread.  Initially, it is slower to spread rhizomes than most other species of Phyllostachys so they need a little extra encouragement. As with most Running Bamboo, rhizomes can be found 1 to 6 inches below the surface, in the loose layer of topsoil. They can sense where the sunlight warms the ground and are programmed to seek out the areas with the most light.  For this reason bamboo most often spreads south, though I suppose if we lived in Australia, the opposite would be true.
    After the third or fourth year, P. nigra can spread by leaps and bounds, over ten feet in one summer, if given good conditions. I have seen an entire yard overtaken by rhizomes from a surprisingly small cluster of canes -the home owner had no idea they were there nor any concept of how to control them.
    On the other hand, I have seen cases where Black Bamboo has remained in the same small space for over 6 years, stranded on a three foot island surrounded by barren clay soil.  This can be used as an advantage for containment.
(see care and maintenance)
    Amazingly, some misinformed sellers still refer to P. nigra as Clumping Bamboo due to its circumstantial growth habits. Oops!
    In order to achieve 30 feet height, it will need space to spread rhizomes; a growing area over 20 feet in circumference or a circle over 6 feet in diameter is the minimum space we recommend for any Phyllostachys. It is possible to confine them in a smaller area, although this requires extra care to maintain good health and rhizome control. (see Care and Maintenance). However, Black Bamboo will probably never reach its full potential in a space under 20 feet circumference.
     Nothing is more impressive in the landscape than a 30 foot tall, jet black culm supporting radiant plumes of lime-green foliage. With the proper care and maintenance, Black Bamboo can be the focal point of any landscape or create a narrow, dense privacy screen. Let your imagination and creativity decide how to best use this wonderful bamboo.

 © Noah Bell, 2007
A six month old culm, in the midst of color transformation.

© Noah Bell, Shweeash Bamboo, 2007
Ten months old, just about fully black.

© Noah Bell, Shweeash Bamboo, 2007
This may be the most pure black culm we have ever seen. Found on P. nigra 'Ebony' growing at Shweeash Bamboo.  Interestingly, it is hidden in almost full shade.