How to Prune moso 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

moso bamboo · Phyllostachys edulis
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 potting compost and feed with a balanced liquid fertiliser monthly during the growing season. May remain clump-forming in poor or dry soils but has the potential to become a nuisance 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