Often confused are the edible Ginger (the root) of commerce and these flamboyant greenhouse ornamentals. However that’s not surprising as they’re closely related, and similar in appearance and habit. However the Kahili ginger, Hedychium gardenerium, is most definitely not edible, which is a bit unfortunate as this grows considerably larger and would make a great crop.
Indeed this gorgeous plant might be a little cramped in the smallest greenhouse needing up to two metres of height when in full flower, plus the depth of the tub. Which needs be generous as these are vigorous, hungry, thirsty and obviously tend to be top heavy.
The leaves are grey green and slim, quite banana like, while the flower-spikes are not only generously tall but delicate, orchid or butterfly like, with many ornate yellow blooms and long bright red stamens. These give off wafts of beautiful scent perfuming your greenhouse especially in late summer evenings. One of the best plants for this purpose as it is a pleasing sweet perfume and not cloying.
Definitely not hardy these are effectively evergreen if kept warm and bright enough otherwise they’ll die down in winter. The roots need be kept several degrees above freezing or they’ll simply rot. If kept warm and dry they recover and regrow in spring. No particular care is needed other than moving into larger containers as a clump swells. Tying the stems to canes will help if they grow outwards too widely though usually these make fairly upright specimens.
It’s simplest to purchase your first root or plant and divide if more are wanted. However these grow rapidly from seed which is also available. In spring sow in a warmed propagator and grow on in bright warmth potting on as plants get bigger.
These flower naturally from summer into autumn and although hungry and thirsty anyway become voracious as the flowers are forming. The blooms will open and stay more beautiful if the atmosphere is also kept a tad humid for their duration, they can, with some regret, be cut to add a tropical flavour to flower arrangements.
There are literally dozens of other Hedychiums for the connoisseur though all need more warmth than H. gardenerium which is the least tender of this lovely family.