Rose hips are the fruit developed by rose plants after bloom and they mature on the rose plant through the fall and often into winter if left in place. Most species of roses produce hips in some size and amount, but old garden, heirloom and classic shrub roses will tend to develop more of them than modern, highly bred cultivars, according to the University of Illinois. Pruning rose hips can be done at several points in their development, depending entirely on your goals for plant performance and the look you like in your garden. Rose hips are edible for humans and contain high levels of vitamin C and are prized by birds and other animals as a food source.
Harvest fresh rose hips at their peak ripeness in the fall. The rose hips are ripe when they become swollen, the skin becomes a deep rich orange or a bright red, the skin is still relatively smooth and they give just slightly when pressed with your thumb. Allow roughly four months after the first flowers have been pollinated for rose hips to develop and be ready for harvest.
Groom the rose hip clusters on your plants during the late summer, fall or early winter by selectively removing single rose hips that may have become discolored, damaged or simply look unsightly. Cut the single hips on the thin, short stem that connects the single rose hip to the larger cluster and discard the cutting. Make the cut carefully so as not to disturb or sever the healthy hips from the cluster.
Prune away any dried and dessicated rose hips leftover on the plant in early spring after the last hard frost has passed. During the winter, animals or inclement weather will usually strip the hips from the rose plants, but occasionally some remain tethered. Cut back the rose cane to a point of live wood, below where the hips are attached, just 1/8 to 1/4 inch above a healthy bud or leaf axil. The dried-up hips can be composted or discarded.