This popular shrub forms a well-branched dense upright rounded habit. It has glossy dark green elliptical leaves that turn yellowish in cooler weather and the solitary fragrant white double or semi double flowers appear from late spring to early summer.  

Hardiness zones 9 to 11

Gardenia jasminoides is naturally found from south-east China to Japan growing in coastal or low-mountain regions and has been cultivated for more than 1,000 years. It prefers a well drained organic rich fertile moist clay loam that is tending acidic with a pH range from 5.5 to 6.5 and grows in a semi shaded to sunny position with protection from hot westerly sun and is drought and frost tender. 

Gardenia is grown for its fragrant flowers and bushy habit. It is planted in shrub borders or in patios pots and tubs and used in courtyard planter boxes. It establishes in 2 to 3 years and is moderately long lived. It is suitable for coastal or mountainous regions and there are three cultivars that are commonly used 'Florida', 'Grandiflora' and 'Radicans'  ID 50

Note:
The flowers commonly become yellowish due to deficiency in iron in alkaline soils. 

Gardenia (gar-DEEN-ee-a)  jasminoides (jaz-min-OY-deez)

'Gardenia': after 18th century Scottish amateur plant collector Alexander Garden; 'augusta': majestic.

Rubiaceae (ROO-bee-AY-see-ee)
Coffee and Madder Family