The silver gardenia
The silver gardenia (Gardenia collinsae, Rubiaceae) is breathtaking when in blossom. Since the flowering period only lasts a short time, many people may not appreciate it in their gardens. For massive blossom you need to sacrifice your lawn, i.e. a period of drought is necessary to trigger flower formation. Off the flowering season it is an anonymous shrub. If your garden is big I should still suggest this species. Then you can mix all year flowering plants with rare local gems such as the silver gardenia. The vernacular English name alludes not only to the white blossom, but to the silvery upright branches.
Normally I discourage people to plant too many gardenias in Chiang Mai due to their sensitivity to excess water and drought, both of which are characteristics of the climate of this part of the world. Royal gardenia (Gardenia coronaria) is another native species. It has yellow flowers, heavenly fragrant in the evening and night, blooming regularly, but prone to aphids and must be planted in a well drained soil which you can easily water.
Common gardenia (G. jasminoides = G. augusta = G. florida) is indeed the most common gardenia you see for sale in Chiang Mai here in northern Thailand. It may do well if cared for, but looks eternally fatigue if not watered generously or will die if planted in a poorly drained soil. It has white flowers (both single and double forms exist) and a roundish shrubby growth. Remember it is native to China, Taiwan and Japan and so adapted to a more wet climate than in Chiang Mai.
Along the Chiang Mai airport is a native tree-sized yellow gardenia in bloom right now, the Doi Suthep gardenia (G. sootepensis). This gardenia is hardy and has enormous flowers. The only problem is that it is so tall you may not see the flowers, unless planted outside a balcony. It is a local hero, named after the mountain Doi Suthep. It only flowers once a year and the flowering period is brief. The Dokmai Garden specimen is already done.
As a curiosity I can mention that in the nearby jungles is a shaking gardenia (Ceriscoides (Gardenia) turgida). I have seen it twice but failed to germinate seeds. The legend of its shaking ability when touched is greatly exaggerated.
The Silver gardenia is in blossom right now at Dokmai Garden.
Text & Photo: Eric Danell