Star Jasmine (Trachelospermum jasminoides) is a popular evergreen vine, celebrated for its glossy foliage and intensely fragrant, white, star-shaped flowers. When trained onto a vertical structure like a trellis, regular pruning is necessary to maintain a uniform shape and dense coverage. Pruning also encourages air circulation and light penetration, which promotes the plant’s overall health and vigorous, flowering new growth.
Timing and Necessary Tools
The optimal time for annual pruning is immediately after the main bloom period has finished in late spring or early summer, typically around May or June depending on the climate. Pruning at this time gives the vine ample time to produce new growth before the next flowering cycle. Since Star Jasmine blooms on new growth, pruning should be avoided in the late fall or winter, as a late-season trim can remove the wood that would set next year’s flower buds.
A light shaping can also be done in late winter or very early spring before new growth begins, though this may sacrifice some early flowers. Gather clean, sharp bypass pruners for precise cuts on individual stems. For thicker, older canes, use bypass loppers for leverage. Since the vine’s stems contain a mildly irritating, milky white sap, wearing garden gloves and long sleeves is a practical precaution.
Routine Annual Shaping and Maintenance
Routine maintenance begins by removing any dead, diseased, or damaged stems, often referred to as the “three D’s.” This clears out non-productive material, improving air flow and making room for new, healthy growth. Focus on thinning out any overcrowded or tangled stems, especially near the center of the plant, to ensure light reaches the lower foliage.
Next, address the stems that are growing away from the trellis or hanging loosely. These wayward stems should be cut back to a set of leaves or a side shoot that is growing toward the trellis. This technique helps maintain the two-dimensional, flat profile needed for a neat trellis covering.
To encourage the vine to fill in and become denser, lightly trim the tips of the remaining stems by a few inches, or about one-third of the previous season’s growth. This tipping action stimulates lateral branching, leading to a fuller, more uniform screen of foliage. Finally, pliable new shoots should be gently guided and secured to the trellis using soft ties or garden twine, ensuring the ties are loose enough to prevent girdling the stem as it thickens.
Restoring Overgrown Vines
When Star Jasmine has been neglected for several seasons, it can become severely overgrown, tangled, and woody at the base, requiring a significant reduction. This aggressive process, known as rejuvenation pruning, is best performed in early spring or immediately after flowering.
Begin by selectively cutting back the oldest, thickest, and most tangled canes by as much as one-half to two-thirds of their length. Make these cuts just above a strong side shoot or bud to direct the plant’s energy into new growth. This heavy reduction stimulates vigorous new shoots, effectively revitalizing the vine. While the vine is resilient, this severe pruning will likely result in fewer flowers the following season, as flowering primarily occurs on older wood.