Winter hardy to USDA Zone 7 to 10. Although ‘Shooting Star’ by reputation has the best winter hardiness of the common gardenias, it still is not reliably winter hardy throughout the St. Louis area. Some nurseries suggest that ‘Shooting Star’ is winter hardy to Zone 6, but such a rating may be a bit optimistic. Other common gardenias exhibiting excellent winter hardiness are usually at best winter hardy to Zone 7. If planted outdoors in the St. Louis area, ‘Shooting Star’ should be sited in a sheltered location protected from winter winds and given an organic root mulch. Best performance may occur in humusy, acidic, well-drained soils in part shade. Consider raised plantings in areas with heavy clay soils. Water plants consistently, but avoid wetting the foliage. Plants grown in pots or containers may be placed outside during the growing season but overwintered indoors. As an indoor plant, grow it in bright light with moderate room temperature. Water moderately but do not allow soils to dry out. Prune after flowering to shape. Fertilize as needed from March to August.
Gardenia jasminoides, commonly called common gardenia or cape jasmine, is native to southern China and Japan and is an evergreen shrub with thick, glossy, dark green leaves (to 4” long). It typically grows to 3-6’ tall. It is particularly noted for its extremely fragrant white flowers (to 3” diameter) and is often grown in double-flowered forms. Flowers bloom throughout the year in warm climates where temperatures do not dip below 60 degrees F., but more typically bloom in late spring to early summer in cooler climates in the northern part of its growing range.
Gardenia jasminoides is synonymous with G. augusta and G. grandiflora.
‘Shooting Star’ is a compact cultivar that typically grows 3-4’ tall and is noted for its winter hardiness and large, fragrant, single white flowers (to 3” diameter). Flowers appear May to June. Glossy, evergreen, ovate to lance-shaped dark green leaves (to 4” long) appear opposite or in whorls. Seeds of this cultivar were reportedly collected at the Beijing Botanical Garden in China.
Powdery mildew, leaf spots, dieback, anthracnose, sooty mold, whiteflies, mealybugs, scales, aphids and spider mites are potential problems. In some areas, whiteflies and scales may be the most serious insect pests. Whitefly infestation often leads to sooty mold. The loss of buds or blackened leaf tips may be the result of changes in temperature or amounts of water. Chlorosis (yellowing of leaves) may occur in soils that are neutral to alkaline.
Containers or pots that are overwintered indoors. Accent plant for sheltered area around homes in areas where it is winter hardy.