Rose hips are the fruit developed by rose plants after flowering and they mature on the rose plant through the autumn and into winter if left in place. Most rose species produce hips, but old garden, heirloom and classic shrub roses tend to develop more than modern, highly bred cultivars. 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 autumn. 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, autumn or early winter by selectively removing single rose hips that may have become discoloured, 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 left 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. Cut back the rose cane to a point of live wood, below where the hips are attached, just 3 to 6.5 mm (1/8 to 1/4 inch) above a healthy bud or leaf axil. The dried-up hips can be composted or discarded.
Leave rose hips on the plants through the autumn and winter, pruning them in early spring, to offer wildlife a much needed food source and give the garden a spot of colour after all the leaves on the rose canes and other deciduous plants have been shed.