Winter treatment: Sarracenia expect spring, summer, fall, and winter seasons. During the spring, they flower. During the summer, they produce their first pitchers early in the season. During the fall, they just sit there; some species make modified, nontrapping leaves during this season. During the winter, the remains of the summer leaves slowly die back. I think winter rest is signalled by cooler temperatures and/or decreased photoperiod/intensities, but I do not really know. You can take advantage of this slow season by trimming the leaves back as they die. Only trim off the dead stuff---never cut into living tissue. Sarracenia oreophila, S. jonesii, and S. purpurea subsp. purpurea expect cold weather and even frosts during the winter. If you keep your plants on a seasonal schedule, they will usually flower for you each spring. This means they are happy!
Indoor growers have their own challenges with Sarracenia. Sarracenia rosea and S. purpurea subsp. venosa do well in terraria year-round without a winter treatment. However, giving them one will encourage normal annual-rhythmic behaviour such as flowering