Culture
Winter hardy to USDA Zones 8-10. In St. Louis, plant rhizomes in spring after last frost date in organically rich, medium moisture, well-drained soils in full sun to part shade (some other species of Curcuma prefer part shade). Plants do well in hot summer with high humidity. Provide regular moisture throughout the growing season and do not allow soils to dry out. Dig rhizomes in fall after first frost, remove top growth and store in a cool, dry location in peat or vermiculite that is kept very slightly moist throughout the winter. Plant rhizomes outdoors in spring. Plants may also be grown in containers that should be overwintered indoors in the pots in a cool dry location with minimal moisture (just enough to keep potting soil from totally drying out).
Noteworthy Characteristics
Curcuma alismatifolia, commonly called Siam tulip, is a rhizomatous tropical perennial in the ginger family that grows to 2’ tall. It is native to Thailand (formerly known as Siam). Inflorescences, stems and leaves of this plant resemble the flowers, stems and leaves of tulips, hence the common name. Siam tulip is a repeat bloomer that produces abundant inflorescences in summer (June-August). Plants go dormant in winter (November to May). Each inflorescence (to 3” tall) consists of showy, petal-like, bracts that surround the tiny, lavender-white, true flowers. The bracts can range in color from white to pink to violet. The true flowers are seen only if they curl around the bracts edges. Each inflorescence appears atop a rigid, reed-like stem that grows to 2’ tall from a clump of narrow, lance-shaped, dark green leaves.
Genus name is the Latinized version of the Arabic name.
'Chiang Mai Pink' is noted for its pink showy bracts with darker pink tips. Mature clumps will reach 1-2' tall with a similar spread.
Problems
No serious insect or disease problems.
Uses
Borders. Containers. Excellent cut flower.