Alpinia zerumbet (shell ginger)

Shell ginger (Alpinia zerumbet) is one of the largest-growing of the commonly cultivated gingers, typically reaching about 8-10 feet in height. The pendulous flower spike emerges from the tip of mature canes. It consists of an 8-inch long cluster of individual flowers. Blooms may appear at any time of the year, but they are most likely in spring and early summer.

Leaflets positioned alternately along the canes are dark green and about 4½ inches wide by 2 feet long. The foliage is evergreen and is only damaged by severe freezes.

The bruised leaves are very fragrant. Dried leaves and stems make an excellent addition to dry or simmering potpourris.
The plant spreads by rhizomes and it doesn't take long to form a massive clump. It makes an excellent background or screening plant if you have the room for it. Old dried canes and leaves remain standing for a long time and manual removal is required to keep the plant looking its best.

The large rhizomes are not edible, but the leaves have many reputed uses in folk medicines.
Alpinia zerumbet is native to eastern Asia and is recommended for USDA Zones 8-12. In Zone 8 the canes may freeze back each year before maturity, preventing the production of blossoms.

There is a variegated form of shell ginger that grows about 6 feet tall, and a dwarf variegated form that only gets about a foot tall.