One of the hardiest hedychiums, Kahili Ginger (Hedychium gardnerianum ) is a bold and architectural perennial that brings an exotic touch to the garden and containers. Kahili Ginger ranks as a top choice among tropical flowers for enthusiasts and gardeners.
I. Appearance and Characteristics
Hedychium gardnerianum, the Kahili ginger, Kahila garland-lily or ginger lily, is a species of flowering plant in the ginger family Zingiberaceae, native to the Himalayas in India, Nepal, and Bhutan. It is an erect herbaceous perennial growing to 8 ft (2.4 m) tall with long, bright green leaves clasping the tall stems. The very fragrant pale yellow and red flowers are held in dense spikes above the foliage. They appear towards the end of summer.
Hedychium gardnerianum is cultivated as an ornamental plant in gardens and parks. It prefers a warm tropical climate, although it can thrive in sub-tropical and temperate regions as it tolerates occasional frosts. In the UK it has been given the Royal Horticultural Society’s Award of Garden Merit. It is best grown in a warm, sheltered spot where temperatures do not fall below freezing, and is given a deep mulch during the winter months. Alternatively it can be grown under glass in a well-lit conservatory or greenhouse.
The plant is a serious invasive species in certain areas. It is known as ‘wild kahili ginger’ and is listed as a weed of concern on conservation land in New Zealand, Hawaii, South Africa and the Azores.
It has been recognized as one of “100 of the World’s Worst Invasive Alien Species” by the IUCN Invasive Species Specialist Group (ISSG).
II. How to Grow and Care
Kahili ginger is a robust perennial known for its ease of care, which thrives in warm, humid conditions with partial to full sunlight. It requires well-draining soil that stays moist but not waterlogged. A special care point for kahili ginger includes providing regular water during the growing season and less during dormancy. Additionally, kahili ginger benefits from occasional fertilization to support its lush growth and vibrant flowering.
Sunlight
Kahili ginger thrives in partial shade conditions, where it receives dappled sunlight that mimics its natural habitat beneath forest canopies. While kahili ginger can tolerate full sun exposure, especially in cooler climates, too much direct sunlight may stress the plant, leading to leaf scorch or reduced vigor. Such conditions can also impact its flowering potential, possibly causing fewer blooms. Kahili ginger may exhibit adaptability through leaf orientation to optimize light absorption. For outdoor planting, positions that provide morning sun and afternoon shade are ideal. Indoors, kahili ginger should be placed in bright, indirect light to promote healthy growth and flowering.
Watering
Originating from tropical regions, kahili ginger thrives in humid environments and has adapted to absorb ample moisture, reflecting its preference for consistent hydration. Its water habits include a resilience to brief dry spells but it flourishes when the soil remains evenly moist without being waterlogged. For optimal growth, kahili ginger requires watering every week. As an evergreen plant commonly grown outdoors, kahili ginger’s lush foliage benefits significantly from dew and rainfall, which contribute to its hydration needs beyond regular watering schedules.
Soil
Kahili ginger performs best in full sun or part shade in humus-rich, moist, well-drained soils.
Fertilizing
To foster kahili ginger’s robust growth and striking blooms, a high phosphorus fertilizer is ideal, usually with a ratio resembling 10-20-10. Fertilize monthly throughout the growing season, reducing to quarterly applications as dormancy approaches. A tablespoon per plant, diluted as per manufacturer’s guidelines, suffices to avoid root burn. Benefits include healthier roots, vibrant flowers, and heightened resilience. Seasonal adjustments in application rates and schedule are crucial, with lighter feedings in cooler months. For effective fertilization, apply at the plant’s base after watering, ensuring nutrients reach the roots without overwhelming the plant.
Mulching
Apply a deep mulch of garden compost or leaf mold to protect your plant in frost-prone areas. Kahili Ginger can withstand temperatures between 10–20°F (-12 to -16°C) with mulching.
Pruning
Cut back the foliage and old flower spikes at the end of the season.
Propagation
Kahili ginger is effectively propagated through division, which involves separating the rhizomes into sections, each with at least one growth bud. Careful handling is essential as sections are teased apart to avoid damaging the buds. Once divided, pieces should be promptly replanted in well-draining soil, ensuring that the buds are just below the surface. Consistent moisture, warmth, and indirect light will encourage healthy root development and new shoots growth.
Transplanting
The optimal time for transplanting kahili ginger is during the heart of spring when growth is robust. Choose a luminous, partially shaded location with well-draining soil to promote a good start. Remember, gentle handling of roots encourages successful adaptation.
Repotting
Re-pot kahili ginger every 2-3 years in spring before the rapid growth phase. Kahili ginger, a large, sturdy perennial, thrives in spacious containers that accommodate its spread. Prioritize a pot with ample drainage to prevent root rot. After re-potting, keep the soil consistently moist and provide partial shade for recovery. These care tips ensure kahili ginger continues to flourish, gracing your space with its striking flowers and lush foliage.
III. Uses and Benefits
Kahili ginger is a great choice as a border or hedge shrub, especially along pathways or garden walls. The plant is most attractive when its fragrant flowers bloom during the summer and fall. Because it can grow in sandy, sunny gardens, it works well in coastal gardens or informal cottage gardens. It can’t handle frost but thrives in hot climates.
