How to Prune yellowish barrenwort?
No pruning required, but cutting back in late winter or early spring, before flower spikes form, will improve appearance

yellowish barrenwort · Epimedium flavum
Grow in fertile, humus-rich, moist but well-drained soil in partial shade, with shelter from cold, drying winds; where frosts are prolonged or severe, spread an organic mulch such as leaf mould or composted bark to protect plants over winter
No pruning required, but cutting back in late winter or early spring, before flower spikes form, will improve appearance