How to Prune iris 'Gwyneth Evans'?
Remove any dying foliage in autumn, old flower stems can be cut down after flowering

iris 'Gwyneth Evans' · Iris 'Gwyneth Evans'
Grow in well-drained neutral to alkaline soil in full sun; acid soils tolerated if reliably well-drained
Remove any dying foliage in autumn, old flower stems can be cut down after flowering