How to Prune dusky cranesbill?
Cut flowered stems and old leaves to the base to encourage new foliage and flowers

dusky cranesbill · Geranium phaeum
Also known as: black widow; dusky-flowered cranesbill; mourning widow
Grow in moderately fertile, moist but well-drained soil in sun or part shade but most soils (unless waterlogged) are tolerated. Especially good in damp shade
Cut flowered stems and old leaves to the base to encourage new foliage and flowers