How to prune iris pseudacorus

Deadhead immediately after flowering in early summer to prevent seeding; cut back foliage in autumn. Remove spent flower heads before seed pods develop. Cut all foliage to low stubs in autumn with loppers or shears. Divide clumps by lifting and splitting the rhizome mat with a spade; dispose of surplus divisions carefully — do not compost near water.

Annual cut-back; deadhead diligently after every flowering; divide every 3–4 years. Yellow flag iris is vigorous — pruning is mainly about containment and tidying. Deadhead promptly after flowering to prevent prolific self-seeding (it is invasive in parts of North America). Cut foliage back to 10–15 cm (4–6 in) in autumn. Divide overcrowded clumps in late summer. Check local regulations before planting near natural waterways.

Remove spent flower heads before seed pods develop. Cut all foliage to low stubs in autumn with loppers or shears. Divide clumps by lifting and splitting the rhizome mat with a spade; dispose of surplus divisions carefully — do not compost near water.