Star Jasmine (Trachelospermum jasminoides) is a popular climbing evergreen known for its glossy, dark green foliage and small, white, star-shaped flowers. This vining plant, which is not a true jasmine but a member of the dogbane family, produces a sweet fragrance, making it a favorite for covering arbors, trellises, and fences. Successful cultivation relies heavily on locating it in a supportive climate.
Star Jasmine’s Hardiness Range
Star Jasmine is a warm-climate species, thriving best in USDA Hardiness Zones 8 through 10. This range means the plant can endure minimum winter temperatures between 10°F and 30°F without severe damage. Zone 8 includes regions like the Deep South and sections of the Pacific Coast, where the plant grows reliably as a perennial evergreen.
Zone 7b, which experiences average minimums as low as 5°F, is the coldest zone where planting is feasible. Growing the standard species here requires significant protective measures. Specialized cultivars, such as ‘Madison’, offer enhanced cold tolerance for these marginal areas.
Surviving Cold Temperatures
Although Star Jasmine is evergreen, cold temperatures at the lower end of its hardiness range can cause leaf browning, known as winter bronzing. Exposure to temperatures near 10°F, especially for extended durations, may cause foliage to suffer frost burn or drop off completely. The plant’s survival depends primarily on protecting its root system from deep or prolonged freezing.
To mitigate cold effects in Zones 7 and 8a, apply a thick layer of organic mulch around the base. A two to three-inch layer of bark or straw insulates the soil and helps prevent freeze-thaw cycles that can injure the roots. During severe cold snaps, covering the vine with a frost cloth or burlap shields the stems and leaves from winter winds and frost. Ensure the soil remains moderately moist during winter, as dry roots are more susceptible to cold damage.
Ideal Site Conditions for Healthy Growth
Beyond temperature, location and soil composition influence Star Jasmine’s growth and flowering. The plant performs best in full sun, which encourages the most abundant production of fragrant white flowers. It tolerates partial shade, but growth tends to be thinner and flowering is reduced. In extremely hot climates, afternoon shade is beneficial to prevent leaf scorch.
The soil must be well-drained. Star Jasmine thrives in loamy soil rich in organic matter, maintaining a slightly acidic to neutral pH (ideally between 5.5 and 7.0). While established plants are moderately drought-tolerant, they require consistent, regular watering during their first growing season to develop a strong root system. Once mature, watering should be deep but infrequent, allowing the top inch of soil to dry out completely between applications.