Hibiscus waimeae
Kokio keokeo
Overview
Hibiscus waimeae is an evergreen tree in the Malvaceae reaching 20-30 feet (6-9 m) tall and 10-20 feet (3-6 m) wide, with a rounded crown carried on one or several trunks up to 12 inches (30 cm) across. Bark is smooth and gray. Leaves are broadly oval to nearly round, 3-6 inches (7.5-15 cm) long, dull medium green, with toothed margins and veins raised on the underside. Flowers are white and 4-6 inches (10-15 cm) across, with a red to pink staminal column projecting 2-3 inches (5-7.5 cm) beyond the petals. Each flower opens in the early morning, deepens to pink through the day, and drops the following morning. Flowers carry a light scent, a trait shared with H. arnottianus. Fruit is a capsule 0.6-1 inch (15-25 mm) long that splits into five valves and releases hairy seeds. Growth runs 24-36 inches (60-90 cm) per year on young trees, which flower 3-4 years from seed. Branches are brittle and split at narrow crotch angles in wind above 40 mph (65 km/h), and roots decline in soil that stays wet.
Native Range
Endemic to Kauai in the Hawaiian Islands, growing on mesic valley slopes, canyon walls, and gulch bottoms between 1,000 and 3,900 feet (300-1,200 m). Populations are concentrated in the Waimea Canyon drainage and in the wet valleys of the north shore. The tree grows on weathered basalt soils under the partial canopy of native mesic forest.Suggested Uses
Planted as a specimen or small canopy tree in Hawaiian gardens and parks at 15-20 foot (4.6-6 m) spacing, and used in mesic forest restoration on Kauai. Grown in containers of 15 gallons (57 L) or larger, where trees stay at 6-10 feet (1.8-3 m) with annual cutting back. Flowers are picked for lei and for wearing, though they wilt within a few hours of picking.How to Identify
Appearance
Size & Dimensions
Height20' - 30'
Width/Spread10' - 20'
Reaches mature size in approximately 12 years
Bloom Information
Main flowering runs February through October, with scattered flowers in every month below 1,500 feet (460 m). Each flower opens between 5 and 8 in the morning, shifts from white to pink through the day, and falls by the following morning, so a single flower lasts under 24 hours. A mature tree carries 10-40 open flowers daily at peak. Flower numbers halve during cool spells below 60 degrees F (16 degrees C).
Detailed Descriptions
Flower Description
white aging to pink, with a red staminal columnFoliage Description
dull medium greenGrowing Conditions
Sun Requirements
Requires 4-8 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
Care & Maintenance
Care Guide
Seed germinates in 2-6 weeks after the coat is nicked, and cuttings 6-8 inches (15-20 cm) long root in 6-10 weeks under mist. Water twice weekly for the first two years, then weekly during dry spells; leaves yellow and drop after 2-3 weeks without water. Soil must drain freely at pH 5.5 to 6.5, since roots decline within one season in ground that stays saturated. Chinese rose beetles chew leaves at night from April through September, aphids cluster on flower buds, and scale insects build up on stems in still air. Trees fed a balanced fertiliser in early spring and again at midsummer hold denser foliage than unfed trees. Lifespan in cultivation runs 20-30 years.Pruning
Branches are shortened in late winter or early spring ahead of the main flowering flush, cutting back to a side branch at least one third the diameter of the removed stem. Crotch angles under 30 degrees split under load and are removed while the stems are less than 1 inch (2.5 cm) thick. Cuts into wood over 3 inches (7.5 cm) across close slowly and often decay. Flowers form on new growth, so trees cut back hard in spring flower again within 10-14 weeks.Pruning Schedule
J
F
M
A
M
J
J
A
S
O
N
D
early spring
Container Growing
✓ Suitable for container growing
Minimum container size: 15 gallons