How to Prune long yellow daylily?
Cut back flower stems after flowering has finished. Remove dead foliage as required.

long yellow daylily · Hemerocallis citrina
Also known as: citron daylily
Grow in fertile, well aerated soil in full sun. Water freely from spring to summer. Divide every 2-3 years to maintain vigour. See Hemerocallis cultivation for more advice
Cut back flower stems after flowering has finished. Remove dead foliage as required.