Family: Rubiaceae

Gardenias are one of the most popular plants for warm climate gardens worldwide because of their exquisite, white, beautifully perfumed blooms which contrast perfectly with their attractive, dark green foliage. Mostly from trop­ical Asia and Africa, there are around 200 species of gardenia. Throughout most of the US gardenias are grown in a warm greenhouse or conservatory but they can be grown outdoors in zone 10 or warmest parts of zone 9.

Species

G. augusta, Cape jasmine, from south-ern China, is the most commonly grown of the species. It grows to 2 m (6 ft) in height, with thick-petalled flowers, blooming naturally in summer. There are numerous cultivars includ­ing 'August Beauty' which freely produces large double flowers from spring to autumn. It is quite a tall plant. More compact is the cultivar 'Mystery', with semi-double, white flowers. Double, pure white flowers grace the erect-growing 'Veitchii'.

G. thunbergia, tree garde­nia, from the forests of southern Africa, is an especially beautiful, though slow-growing, species, to 3.5 m (11 ft), which will thrive in any rich, well-drained soil. It has broad, glossy leaves and fragrant, single, white flowers.

Cultivation

These tender, evergreen shrubs are best grown in a warm greenhouse or conserva­tory, in large pots or tubs of acid (lime-free) pot­ting compost. They need maximum light but shade from direct sun. Provide moderate humidity. Water normally in the growing period, using lime-free water, but very sparingly in winter. Liquid feed once a month in spring and summer. Propagate from semi-ripe cuttings in late summer.

Climate

Warmest parts of zone 9, zone 10 and tropical.