Culture
Winter hardy to USDA Zones 10-12 where it is best grown in moist, humusy, well-drained soils in part shade. Needs some protection from hot afternoon sun. Likes humid growing conditions. Site in locations protected from strong winds which can do significant damage to tall plants. Very sensitive to frost. Stems may be cut back after flowers fade. Propagate by division, stem cuttings or seed. Plants will spread by rhizomes to form colonies in optimum growing conditions. This plant grows extremely well in greenhouses with high humidity and minimum temperatures of 60-70°F. In greenhouses, soils should be kept moist throughout the growing season but relatively dry during winter dormancy. Plants may be grown in containers as houseplants in bright indoor light.
Noteworthy Characteristics
Dichorisandra thyrsiflora, commonly called blue ginger, is an upright, clump-forming, tropical evergreen perennial that typically grows to 3-6’ (less frequently to 8’) tall on upright, fleshy, cane-like stems. Notwithstanding its common name of blue ginger, this plant is in fact a member of the spiderwort family (Commelinaceae) and not the ginger family (Zingiberaceae). It reportedly resembles a blue-flowered ginger, hence the somewhat confusing common name.
Blue ginger is native to southeastern Brazil. It is noted for producing showy violet blue flowers (to 3/4”) in large terminal inflorescences (to 8” long) of stalked cymes. Bloom time most often occurs from June to October, but sometimes occurs year round. Alternate, sessile, lance-shaped, glossy, deep green leaves (to 8-12” long but only 2” wide) have sheathing bases. Leaves are spirally arranged around the stems. Fruit is a capsule. Seeds are embedded in false red arils.
Genus name comes from the Greek words dis meaning two, chori meaning separate, and andros meaning anther in reference to the stamen arrangement on each flower (four upright and two spreading).
Specific epithet comes from the Latin words flora meaning flowers and thyrsus meaning football-shaped panicle known as a thyrse in reference to the shape of the flower inflorescences.
Problems
Susceptible to root rot in overly moist, waterlogged soils.
Uses
Blue flowers can be spectacular. Mass, group or specimen. Best in a sheltered growing site. Containers for indoor growth as houseplant.