How to prune sweet flag

Early spring for seasonal tidy; ad hoc removal of dead foliage. Snip dead or yellowing leaves cleanly at their base. For spring cleanup, cut back old foliage to within 5–8 cm of the ground or water level. Divide overcrowded clumps in spring or autumn to keep vigour.

Annually in spring, with occasional dead-leaf removal. Sweet Flag (Acorus calamus) needs minimal pruning. Remove dead, yellowing, or damaged leaves at the base as they appear. In early spring, cut back any frost-damaged or winter-tatty foliage before new growth pushes through. The plant spreads by rhizome — divide congested clumps every 3–4 years rather than relying on pruning to manage size.

Snip dead or yellowing leaves cleanly at their base. For spring cleanup, cut back old foliage to within 5–8 cm of the ground or water level. Divide overcrowded clumps in spring or autumn to keep vigour.