The key to harvesting a good crop of rose hips begins with discipline throughout the growing season to not remove flowers from the rose bush. This is not always as easy as it sounds. Cutting roses for use in household arrangements is part of the pleasure of growing roses. Conversely, roses left on the plant can look messy as they fade, and it is tempting to tidy up the plant by deadheading. Rose hip fruits are essentially plant ovaries that form on the stem of a spent flower head, so no pruning at all leads to the best crop. Rose hip formation, and seed head development in general, is an energy drain for all plants, so water and fertilize regularly to ensure a luscious crop.
Refrain from harvesting or deadheading rose flowers from the plant throughout the growing season. Allow rose hips to form and develop at the end of the stem where the base of the flower once was.
Water your roses regularly and deeply throughout the growing season, never allowing the soil to dry out or forcing the plant to strain for water. Feed your roses monthly with a good quality organic rose food, such as Rose-tone, fish emulsion or a commercial formula. Apply fertilizer according to label directions around the roots of the plant and water in well.
Allow rose hips to ripen and mature on the stem before harvesting. At maturity, the hips will have swollen to a full, round shape and deepened in color to a bright orange or russet red. Rose hips will begin to feel slightly soft to the touch when fully ripe.
Harvest your ripe rose hips with clean sharp secateurs in hand. Cut off the hips in bunches at a main stem, placing the cut at least 1/4 inch above a leaf node or bud.
Set the hips down gently into a collection basket to prevent bruising or split damage to very ripe hips.