Pansies & Violas are extremely tough and resilient plants despite their beautiful and delicate appearance. Once acclimatized they are able to withstand freezing temperatures and are fully hardy.
Pansies generally thrive under cool conditions and thus perform best in spring and fall, when they are most popular and in full bloom. Over summer plants tend to become leggy and unsightly and are best placed in the back of a bed and a shady location.
Pinch back plants in mid summer to encourage a more compact habit and encourage buds for fall. Deadhead spent flowers to avoid plants forming seedheads, which will reduce the amount of subsequent blooms.