How to Prune grandfather's beard?
deadhead to promote more blooms, and cut back old stems after flowering

grandfather's beard · Geum triflorum
Also known as: lion's beard; old man's whiskers; prairie smoke; purple avens
Grows best in a moist but well-drained soil, rich in organic matter, in sun or even a certain amount of shade. Divide every few years to avoid congestion
deadhead to promote more blooms, and cut back old stems after flowering