Jasminum officinale, the common white jasmine, is a native of the Himalayas and a twining vine that grows up to 30 feet in length. This summer jasmine is possibly the most-well-known of the species, thanks to its highly fragrant flowers, which bloom summer through fall. In the United States, jasmine is hardy to USDA zones 7b and 8. Pruning is necessary to control its rapid growth, to keep the plant healthy and to maintain a neat appearance.
Prune the jasmine stems that have just finished flowering back to a side shoot. Jasmine blooms on new and old wood. By trimming the plant just after its blossoms fade, you give new wood time to develop and produce buds for the next season.
Sort through clumps of tangled jasmine branches, removing spindly ones and retaining the stronger-looking canes. This thinning makes room for air and light to circulate through the vine, keeping it healthy. It also helps to maintain a neat appearance.
Cut overgrown jasmine vines to within 2 feet of the main trunk. However, be aware this "hard pruning" has a short-term effect, as it also promotes rapid plant growth. Keep up with it by retaining strong stems and training them to support the vine. Prune everything else.
Hard pruning the vine as described in Step 3 delays new blooms by two to three years.