How to Prune bachelor's buttons?
No pruning required

bachelor's buttons · Craspedia glauca
Also known as: common billy buttons
Grow in sharply-drained, low-fertility, humus-rich, gritty soil in full sun; protect from excessive winter wet. Under glass, grow in a mix of equal parts loam, leaf mould and sharp sand, with a top-dressing of grit. Water freely when in growth (avoiding the foliage); keep just moist in winter
No pruning required