How to Grow Black Bamboo Plants

Black bamboo (_Phyllostachys nigra_) is named for the color of its stems, which turn black when the plants are 1 to 2 years old. Growing 35 to 50 feet tall, black bamboo grows in U.S. Department of Agriculture plant hardiness zones 5 through 11. A running bamboo that spreads aggressively in ideal growing conditions, grow black bamboo in containers or sink barriers into the soil help stop the plants from spreading. At the cooler end of its hardiness range black bamboo spreads more slowly than in warm climates.

Partially shaded or sunny areas works best for black bamboo. The plant also grows best in moist soil, though it tolerates heavy clay, loam and sandy soil and acid, neutral and alkaline soil.

Over time, black bamboo spreads to fill any gaps within barriers in the soil, so you can space black bamboo plants as far apart as suits your needs, but closely spaced plants are less likely to grow tall.

If you're growing black bamboo as a privacy fence, space the plants so that the edge of one clump is 3 to 5 feet from the edge of the next clump. When growing black bamboo in a bed, you can space the plants farther apart. One black bamboo plant can spread 20 feet wide after five or more years.

Regular watering helps black bamboo thrive. When watering black bamboo, apply enough water to moisten the soil to the depth of the root balls, but don't make the soil soggy.

Newly planted black bamboo needs evenly moist soil through its first growing season to establish a deep, vigorous root system. Water young black bamboo when the soil surface is dry.

Established black bamboo needs water every week while the plant is growing, and in hot, dry weather it may need water more frequently. Water mature a black bamboo plant when the soil is dry to a depth of 1 to 2 inches.

Organic fertilizers provide black bamboo with a range of nutrients, or you can fertilize with lawn fertilizer, which supplies the main nutrients black bamboo needs.

Aged cow manure or horse manure are organic fertilizers that encourage fast growth in black bamboo plants. Spread a layer of aged manure 3 to 4 inches deep around the plants in early spring before new shoots appear, and apply another layer in midsummer, when the rhizomes -- shoots that grow sideways along or just under the soil surface -- begin to spread.

Alternatively, evenly sprinkle granular 11-2-2 lawn fertilizer around the black bamboo stems at the same times of year. Apply the fertilizer at a rate of about 1 ounce per 100 square feet, and water the fertilizer into the soil.

Growing black bamboo in containers or placing barriers into the soil helps slow its spread. Containers for black bamboo must have drainage holes and should be 24 to 26 inches deep. If you would like to sink containers into the soil, allow a 4- to 6-inch lip to protrude above the soil surface, which helps prevent the rhizomes from spreading.

Soil barriers for black bamboo can be made of galvanized metal, concrete or root barrier material. The barriers should be at least 20 inches deep and protrude 4 to 6 inches above the soil.

Once or twice a year, check black bamboo plants for rhizomes that are climbing the barriers. Prune the rhizomes with pruning shears that have been sterilized by wiping the blades with a cloth that was soaked in rubbing alcohol. Sterilize the pruning shear blades again when you've finished pruning.