In drier regions, where the moisture-dependent plant requires significant watering, many specimens across the country will inevitably perish. The RHS recommends several methods for managing the hybrid: cutting back and applying herbicide, complete removal, or preventing seed spread by cutting flower heads before they mature and composting cautiously. This can be done by cutting flower spikes at their base in July or August using a gardening knife or pruning saw. John David, head of horticultural