Black bamboo for sale is best planted in early spring which will result in the fastest growth. They are mostly sold in bare root form. Starting from a small size, most bamboo will reach mature height within five or six years. Under ideal conditions Black Bamboo will grow to 35 feet in height with culms over 2 inches in diameter, but 25 feet is its average height in most climates. The stems of black bamboos grow in green and it may take 2 to 3 years for them to turn black.