This species is listed on Schedule 9 of the UK Wildlife and Countryside Act as an invasive, non-native species. While this does not prevent it from being sold in the UK, or from being grown in gardens, the RHS encourages those that do grow it to take great care with managing it and with disposing of unwanted material. The RHS also encourages gardeners to find alternative plants to grow to those listed on Schedule 9. For suggested alternative plants see the Plantlife/RHS guide: Gardening without harmful invasive plants
No pruning required, except removal of dead leaves and flower stems in autumn, or before new growth starts in spring
Propagate by
division of established clumps in spring, just before new growth starts