How to Prune black bamboo?
Remove weak, dead, damaged or spindly stems in spring and thin to show off stems to best effect. Cut out any flowering shoots promptly to discourage more from forming - see bamboo cultivation

black bamboo · Phyllostachys nigra
Also known as: kuro-chiku; whangee cane
Grow in fertile, humus-rich, moist but well-drained soil, in full sun or partial shade. Protect from cold drying winds. In a container grow in a loam-based compost and feed with a balanced liquid fertiliser on a monthly basis during the growing season. May remain clump-forming in poor or dry soils but can become invasive in warm, moist or favourable conditions; see bamboo control and bamboo cultivation
Remove weak, dead, damaged or spindly stems in spring and thin to show off stems to best effect. Cut out any flowering shoots promptly to discourage more from forming - see bamboo cultivation