Proper care of plants in the cold winter months includes cutting back your deciduous perennials. Knowing when and how to cut them back allows the perennials to focus on the growth necessary in early spring to maximize the foliage and blooms throughout the year. Without proper care and attention, the plants will have to fight through the old growth in the spring time. Perennial winter cut back is an important aspect of a landscape that is often overlooked; the time and effort spent during the off season will make a noticeable difference during the peak season.