The hau flower, a captivating bloom found across tropical coastlines, offers both visual splendor and a rich history. Its striking appearance and adaptable nature have endeared it to cultures worldwide, making it a subject of fascination for gardeners and enthusiasts alike. This plant serves as a reminder of the intricate connections between nature and human tradition. Understanding its characteristics and needs can deepen one’s appreciation for this remarkable botanical specimen.
What is the Hau Flower?
The hau flower (Hibiscus tiliaceus), a mallow family member, is also known as Sea Hibiscus, Beach Hibiscus, Coastal Hibiscus, Coastal Cottonwood, or Mahoe. This sprawling shrub or small tree typically reaches 10 to 33 feet tall, occasionally up to 66 feet, with trunks often featuring curved branches.
Its distinctive foliage includes large, heart-shaped leaves, sometimes variegated in pink, green, and cream. The trumpet-shaped flowers, up to 4 inches wide, transform throughout the day: opening bright yellow with a deep red center, then deepening to orange, and finally turning red before falling.
Pantropical in distribution, hau thrives along tropical and subtropical coastlines. Common in coastal environments like beaches, riverbanks, and mangrove swamps (sea level up to 2,600 feet), it is well-adapted, tolerating salt spray, waterlogging, and various soil types (quartz, coral, marl, limestone, crushed basalt).
Cultural Significance of Hau
The hau flower holds deep cultural importance, especially in Hawaiian traditions and other Pacific island communities. Regarded as a canoe plant, Polynesians transported it for its beauty and survival value. Its rapid daily life cycle, with blossoms opening yellow and turning red before falling, is metaphorically associated with the transient nature of human life.
Hau was incorporated into lei making, though its delicate petals mean leis typically last only a day. Its presence is woven into hula performances, ceremonies, and storytelling (moʻolelo), reflecting its integration into daily life and spiritual beliefs. The tree is sometimes considered sacred, with legends linking its genealogy to Polynesian deities.
Beyond symbolism, hau indicated community activities; branches piled near shorelines traditionally signaled forbidden fishing, often during spawning periods. This highlights its multifaceted role, from spiritual symbolism to practical communication.
Growing and Caring for Hau
The hau plant is a versatile, low-maintenance choice for tropical and subtropical gardens. It thrives best in full sun for optimal growth and flowering; partial shade is tolerated. Adequate sunlight ensures vibrant blooms and robust plant development.
Hau adapts well to soil, growing in types from sandy to loamy, poor or muddy soils. While preferring well-draining conditions, it tolerates poor drainage and waterlogging, suiting various garden settings. It thrives in slightly acidic to alkaline conditions (pH 5-8.5).
Established hau plants are drought-tolerant, surviving on rainwater in many coastal areas. Newly planted specimens benefit from daily watering to encourage strong root systems. Regular watering is advisable during dry periods to maintain consistent soil moisture, avoiding extended waterlogging after establishment. Hau thrives in warm, humid climates, tolerating light frosts but not suited for very cold regions.
Pruning benefits hau by maintaining shape, promoting bushier growth, and removing dead or damaged wood. Light pruning after flowering controls size and encourages new blooms. Propagation occurs via seeds (germinating in about 15 days in warm weather) or semi-hardwood cuttings taken in late spring/early summer and rooted in well-draining potting mix.
Traditional and Modern Uses of Hau
The hau plant has diverse practical applications beyond its ornamental appeal. Its lightweight yet strong wood was historically used for traditional implements: canoe parts (outrigger booms, ʻiako), fishing net floats, adze handles, practice spears, and kite cross-beams.
The fibrous inner bark was highly valued for strong cordage, used for lashing, weaving mats, and producing bark cloth (kapa). This cordage was essential for daily tasks, including securing items, fishing lines, and hula skirts. Leaves served as food wrappers; young shoots were consumed as a vegetable.
In traditional medicine, various hau plant parts addressed ailments. Flower buds and sap served as a mild laxative; chewing small leaf buds relieved dry throats. Decoctions of leaves and roots were traditionally used for fever, coughs, chest congestion, ear infections, diarrhea, dysentery, and typhoid. Today, hau is widely planted for landscaping as an ornamental, and its extensive root system helps stabilize soil and prevent coastal erosion.
Cultural Significance of Hau
…Its presence is also woven into hula performances, ceremonies, and storytelling (moʻolelo), reflecting its integration into daily life and spiritual beliefs. The tree itself is sometimes considered sacred, with legends linking its genealogy to Polynesian deities.
Beyond its symbolic meanings of resilience and adaptability, hau played a role in indicating community activities. Traditionally, branches of hau were piled near shorelines to signal that fishing in that area was forbidden, often during spawning periods. This highlights its multifaceted role, extending from spiritual symbolism to practical communication within ancient communities.
Growing and Caring for Hau
The hau plant is a versatile choice for tropical and subtropical gardens, known for its adaptability and relatively low maintenance requirements. It thrives best in locations that receive full sun, which promotes optimal growth and flowering, although it can also tolerate partial shade. Adequate sunlight helps ensure vibrant blooms and robust plant development.
When it comes to soil, hau is highly adaptable, growing in a wide range of types from sandy to loamy, and even in poor or muddy soils. It prefers well-draining conditions but can also tolerate soils with poor drainage and waterlogging, making it suitable for various garden settings. The plant is not particular about soil pH, thriving in slightly acidic to alkaline conditions, generally between pH 5 and 8.5.
While established hau plants are drought-tolerant and can survive on rainwater alone in many coastal areas, newly planted specimens benefit from daily watering to encourage a strong root system. Regular watering is also advisable during dry periods to maintain consistent soil moisture, though care should be taken to avoid waterlogged conditions for extended periods after establishment. Hau thrives in warm, humid climates and can tolerate light frosts, but it is not suited for very cold regions.
Pruning is beneficial for the hau to maintain its desired shape, promote bushier growth, and remove any dead or damaged wood. Light pruning after flowering helps control its size and encourages new blooms. Propagation can be achieved through both seeds and cuttings; seeds germinate in about 15 days when sown in warm weather, while semi-hardwood cuttings taken in late spring or early summer can be rooted in a well-draining potting mix.
Traditional and Modern Uses of Hau
The hau plant has a long history of diverse practical applications, extending far beyond its ornamental appeal. Its wood is notably lightweight yet strong, making it suitable for various traditional implements. Historically, it was used for crafting canoe parts, such as outrigger booms (ʻiako), as well as floats for fishing nets and handles for adzes. The wood’s unique properties also made it useful for making light-weight practice spears and cross-beams for kites.
The fibrous inner bark of the hau was highly valued for creating strong cordage, which served numerous purposes including lashing, weaving mats, and even producing a form of bark cloth (kapa). This cordage was essential for daily tasks, from securing items to making fishing lines and hula skirts. Some cultures also utilized the leaves as natural wrappers for food, and young shoots were consumed as a vegetable.