Costus spp.

spiral gingers

Costaceae

Wet tropics of the Americas, Africa, and Asia

Attracts Pollinators Attracts Butterflies Attracts Hummingbirds Container Friendly

SunPart Shade – Full Sun

WaterHigh

HardinessZones 9–11

Overview

Costus spp. is a genus of tropical perennials in the family Costaceae, known as spiral gingers, with the leaves arranged in a spiral up fleshy, cane-like stems. Once placed in the ginger family, these plants are now in their own family and lack the strong aroma of true gingers. Plants grow from rhizomes into clumps 2-10 feet (0.6-3 m) tall, with broad, oval leaves often hairy or silky beneath. The flowers emerge from dense cone-like heads of overlapping bracts at the stem tips; each bloom is short-lived but the heads open in succession over weeks. Flowers are white, yellow, orange, pink, or red, often with frilled lips, and the colored bracts can be red, pink, or green. The genus is native to the wet tropics of the Americas, Africa, and Asia, growing in forest understory and clearings. Costus spp. needs warmth, humidity, and rich, moist soil and grows outdoors only in frost-free climates, USDA zones 9-11. Plants are grown as container and greenhouse subjects elsewhere. Stems die back in cool or dry periods, and the clumps can spread widely by rhizomes in suitable ground.

Native Range

Costus spp. is native to the wet tropics, with most species in Central and South America and others in tropical Africa and Asia. Plants grow in the understory and along clearings of rainforest and in moist, shaded ground. The genus reaches its greatest diversity in the American tropics.

Suggested Uses

Grown in tropical and shade borders, beside ponds, and in large containers for the bold foliage and cone-like flower heads. In frost-free climates the genus is used as understory and mass planting. Several species are grown as greenhouse and conservatory plants in cool regions.

How to Identify

Identify Costus spp. by the spiral arrangement of leaves climbing around fleshy, unbranched stems, which separates spiral gingers from true gingers with their two-ranked leaves. The flowers rise from a tight cone of overlapping bracts at the stem tip, each flower with a broad, often frilled lip. The lack of a strong ginger scent in the crushed stem is a further clue.

Appearance

Size & Dimensions

Height2' - 10'

Width/Spread2' - 5'

Colors

Flower Colors

Foliage Colors

Fall Foliage Colors

Bloom Information

Bloom Period

~10 weeks

Summer Fall

Flowering occurs through the warm, wet season, in the tropics over much of the year and in cultivation mainly in summer and autumn. Each cone-like head opens a few short-lived flowers at a time over several weeks. Bloom needs warmth and high humidity.

Detailed Descriptions

Flower Description

white, yellow, orange, pink, or red

Foliage Description

green

Growing Conditions

Sun Requirements

SunPartial Shade SunFull Sun

Requires 3-8 hours of direct sunlight daily

• Full Sun: 6+ hours of direct sunlight

• Partial Shade: 3-6 hours of direct sunlight

• Full Shade: Less than 3 hours of direct sunlight

Soil Requirements

pH Range5.5 - 7.0(Neutral)

357912

Soil Types

loam peat

Drainagemoist

Water & Climate

Water Needs

High

Frost Tolerance

tender

Time to Maturity

Flowers within one or two seasons

Care & Maintenance

Care Guide

Costus spp. species grow in partial shade to full sun in rich, moist, well-drained soil with a pH near 5.5-7.0. The genus needs constant warmth, high humidity, and steady moisture and stops growth below about 55F (13C). Plants are heavy feeders during active growth and respond to a thick organic mulch. In containers they need a humid spot, bright indirect light, and reduced water when growth slows. Hardy outdoors only in USDA zones 9-11, the rhizomes can be lifted and stored or kept frost-free over winter. Dry air causes brown leaf edges.

Pruning

Old flowering stems are cut to the ground after they finish, as each cane flowers only once. Clumps are divided in spring to control spread and propagate. Damaged or dead leaves are removed through the season.