It can be tempting this time of the year to prune your perennials. However, this is the opposite approach that you should take. When these plants are trimmed backed they become more susceptible to crown frost. If this occurs it can create more die off or the loss of the plant entirely.
In warm winter climates like in south Louisiana, this can actually be a good time to plant perennials. However, if you do, be sure to keep an eye them, specifically during wet periods. Due to their slower growth, influenced by lower temperatures, diseases and rotting develop.
For perennials that you may be planting, or existing plants, be sure to water them during dry spells. As stated above, they will grow more slowly during the colder months, so they won't need much. It's also a good time to mulch and compost around these plants. The compost breaks down slowly, steadily releasing nutrients and improving the condition of the soil. Fresh mulch provides enhanced protection from the cold. Replace your old mulch with hay or evergreen boughs to insulate the ground.
Eventually your perennials will need to be pruned. However, you should wait until after the final frost of the season, usually occuring in late February or early March.
