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Products > Hibiscus clayi
Hibiscus clayi - Red Kauai Rosemallow
Image of Hibiscus clayi
Habit and Cultural Information
Category: Shrub
Family: Malvaceae (w/Bombacaceae & Sterculeacea)
Origin: Pacific Islands
Evergreen: Yes
Flower Color: Red
Bloomtime: Spring/Fall
Synonyms: [Hibiscus newhousei]
Height: 10-16 feet
Width: 4-6 feet
Exposure: Full Sun
Irrigation (H2O Info): Medium Water Needs
Winter Hardiness: 30-32 F
Hibiscus clayi (Red Kaua?i Rosemallow) - A long lived tall, dense and upright shrub or small tree to 10 to 15 feet tall with smooth edged shiny green leaves. This plant produces its showy dark red flowers with 2 to 2 inch wide flaring petals that are held near the ends of the branches year round in in its native Hawaiian islands but tends to bloom here in Santa Barbara spring through fall with peak in early summer (June & July). Plant in full sun with regular garden water. It is hardy to a light frost but best in coastal near frost free gardens. This is a nice garden plant or it can be kept as a container specimen. This plant was once more widespread on the island of Kaua?i in the Hawaiian Islands but because of cattle and wild pig grazing, as well as habitat loss, it is now restricted to a few of the drier forests of eastern Kauai north of Kapa'a. It is federally listed as an Endangered Species and is listed as Critically Endangered on the IUCN Red List. The naming and conservation of this plant make for an interesting story. In 1928, Albert W. Duvel discovered several small hibiscus trees on Kauai that had been damaged by cattle. Duvel had a landscaping business and he essentially rescued the plants by bringing them into cultivation. The plant was later determined to be a new species that Isa and Otto Degener first named in 1959 in their Flora Hawaiiensis (AKA New Illustrated Hawaiian Flora) with the name honoring Horace F. Clay, a horticulturalist and instructor of botany at Leeward Community College on O?ahu. Margaret James Roe, in her study of the genus Hibiscus in Hawaii, named H. newhousei as another species from Kauai, but the currently accepted treatment is that H. newhousei is a synonym of H. clayi. The name for the genus comes from 'hibiscos' ,the Greek name for mallow. It is commonly called Red Kaua?i Rosemallow or Clay's Hibiscus but its Hawaiian name is Koki?o ?ula with "ula" meaning red. With its abundance of year-round flowers available, these flowers are often found in beautiful leis. We also grow another endemic Kauai hibiscus from the island of Kauai, the orange flowering Hibiscus saintjohnianus. We thanks our salesman Matthew Roberts for sharing the cuttings of this plant from his Santa Barbara garden with us.  The information about Hibiscus clayi displayed on this page is based on research conducted in our nursery library and from online sources we consider reliable. We will also relate those observations made of this plant as it grows in our nursery gardens and in other gardens that we have visited, as well how the crops have performed in containers in our nursery field. We will also incorporate comments we receive from others and welcome hearing from anyone who has additional information, particularly when they share cultural information that would aid others in growing it.