Native to tropical Asia and found growing wild near rivers and waterfalls, Zingiber zerumbet is a clumping perennial that spends most of the year as a quietly handsome stand of reed-like stems and broad, aromatic leaves reaching 4 to 6 feet tall. The real theater arrives near the end of the growing season, when cone-shaped floral structures emerge directly from the ground. They start the color of young limes, with small cream blossoms peering out between the bracts. Then they deepen to a showy, saturated red — and at that moment, squeezing the cone releases a slippery, soap-like liquid with a clean ginger scent. Its use as a traditional hair wash is not incidental; it is the origin of the name Shampoo Ginger.

In zones 8 to 10, it can stay in the ground year-round in a reliably moist spot, though it goes fully dormant in winter and must be kept dry during that rest. In colder climates, the rhizomes need to be lifted after dormancy sets in, stored in a paper bag with a little dry sawdust to absorb any residual moisture, and kept cool until spring. The fleshy pseudostems are mostly water, which makes them surprisingly sturdy, and the large leaves have long been used in cooking as a wrapper that imparts gentle ginger flavor to fish. Spreading by rhizomes, it can expand its territory vigorously given good conditions — a tendency worth watching in a small garden, but welcome in a large tropical-themed planting where its architectural presence fills space with genuine authority.