How to Prune horned pansy?
Deadhead to prolong flowering. After flowering cut back vigorous plants to keep compact

horned pansy · Viola cornuta
Also known as: baby faces; bedding pansy; horned violet; Pyrenean violet; tufted pansy; viola
Grow in fertile, humus-rich, moist but well-drained soil in full sun or partial shade
Deadhead to prolong flowering. After flowering cut back vigorous plants to keep compact