Alpinia hainanensis is a large, fast-growing species of ginger. At first glance, one might assume it is a shell ginger, but there are several key distinctions.
This species grows about 6 feet tall and tolerates sun or shade. Flowers appear in spring at the top of all mature canes. The inflorescence is an arching cluster of a couple dozen flowers, opening in sequence.
The floral buds are soft pink and open to reveal a reddish throat and large, bright yellow lip marked by red striations.
Pollinated flowers develop into round green fruits that develop over the summer.
By late summer, the seedpods mature and turn bright orange. They keep good color throughout the winter. It is these orange fruits that are grated and used as a cardamom substitute.
Alpinia hainensis multiplies by long rhizomes that spread out underground from each cane.
This results in a fast-spreading plant with canes spaced a foot or more apart. The canes are evergreen and will live for several years.
The leaves are about 30 inches long, and glossy, with distinctive ruffled edges. The leaves and stems are highly fragrant when brushed against.
The native region of Alpinia hainanensis is south-east Asia. It is one of the hardiest of the Alpinias, surviving underground in USDA Zone 8, although flowering won't occur where the canes freeze back.
Propagation is normally by division of the rhizomes, but it is also easily grown from seed.
There is a horticultural cultivar sold under the name 'Pink Perfection'.