Hedychium gardnerianum aka Ginger Lily

Hedychium gardnerianum belongs to the ginger family. Its common name is Kahili ginger. Its native range runs from Nepal to Indo-China. People grow it in tropical and subtropical regions worldwide. This plant is a herbaceous perennial: it has soft stems and lives for years. It grows from thick, fleshy rhizomes, or underground stems. It forms upright clumps that spread to make colonies. Garden plants reach about 5–8 feet [1.5–2.5 metres] tall. They spread about 1.6–3.3 feet [0.5–1 metre] wide. They grow fast, reaching full size in two to five years.

Long leaves clasp the tall, green stems in alternate rows. They range from bright green to grey-green, with smooth edges. Some are oval; others are narrow and pointed. The leaves feel papery and have no hairs. Fleshy leaf stalks overlap to form false stems called pseudostems. These rise from the rhizomes below ground. The RHS lists the leaves as deciduous, meaning they fall seasonally. The large leaves make borders look lush before flowers appear.

Dense groups of flowers rise above the leaves in late summer. The blooms range from pale yellow to lemon-yellow. They have long, red stamens and a strong scent. Stamens are the flower parts that bear pollen. The plant may bloom into early autumn. Chicago Botanic Garden lists blooms from July to October. Butterflies, moths and hummingbirds visit the flowers. Showy seed pods, called capsules, ripen in late autumn. Each has three parts and turns from green to brown. They hold seeds with fleshy orange coats called arils. Birds spread the seeds beyond the parent clump.

Grow this ginger outdoors in sun or partial shade. It needs rich soil that stays moist but drains well. Sources list clay, loam, sand and chalk as suitable soils. The RHS accepts acid, neutral and alkaline soil. Shield plants from cold winds. Mulch the rhizomes where frost poses a risk. Give plants in pots bright, indirect light under glass. The RHS rates it H2; it cannot withstand freezing. US sources give zones 7–10 and 8–11. Plants may need winter cover or shelter indoors.

Use it in borders, small groups, pots or conservatories. Cut back spent flowers and leaves at the season’s end. Divide the rhizomes in spring to grow more plants. Serious disease is rare, but aphids and spider mites may attack greenhouse plants. In Hawaii, the rhizomes spread and form dense growth. This growth forces out other plants. Its invasive status there matters when choosing where to plant. NC State lists the roots as edible but lacking flavour. The ASPCA lists it as non-toxic to cats, dogs and horses.