How to Prune sword lily 'Nymph'?
Remove spent flower stems and allow foliage to die down naturally

sword lily 'Nymph' · Gladiolus 'Nymph'
Plant 10 to 16cm deep in fertile, well-drained soil preferably in full sun. Lift when foliage dies back, discard old corms and store new corms in a dry, frost-free place until planting in the spring. In milder areas a thick, dry winter mulch may suffice
Remove spent flower stems and allow foliage to die down naturally