Looking at Plants
Hibiscus rosa-sinensis 'Hawaiian Sunset'
Hibiscus rosa-sinensis ‘Hawaiian Sunset’
COMMON NAMES
Hawaiian Sunset Hibiscus
Hibiscus (hy-BIS-cus) - the Greek name for mallow
rosa-sinensis (RO-sa) (sin-EN-sis) - Chinese rose
‘Hawaiian Sunset’ - cultivar name, a sport of ‘Florida Sunset’
Note: There is some cloudiness in the labeling of this cultivar. I have also seen it labeled as ‘Hawaiian Sundown’. The flower that is registered with the International Hibiscus Society with the name of ‘Hawaiian Sunset’ is slightly different with more muted colors and without the dark red center. There is a possibility of original mislabeling that has just spread or it is an unregistered cultivar from an individual grower. At any rate, this flower, as shown, is widely seen in the trade as ‘Hawaiian Sunset’.
GROUP 
Dicot
FAMILY
Malvaceae
ORIGIN
Species - China, Southeast Asia
DESCRIPTION
Hawaiian Sunset Hibiscus is an evergreen shrub/small tree that averages 6 to 8 feet in height with a spread of 6 to 8 feet. Its habit of growth is upright, symmetrical, and many-stemmed with a moderately dense crown. It is sometimes trained as a small tree. It has a moderate to fast growth rate.
Leaves are evergreen, alternate in arrangement, shiny, simple with serrate margins, and dark green in color.
The flowers are yellow with hues of red, orange, and pink and a dark red throat, 6 to 7 inches across, single, frilly margined, and usually bloom most of the year in warmer areas. The flowers usually only stay open one day.
Fruit are oval capsules.
HARDINESS
It is hardy in USDA Zones 9 to 11 down to mid 20’s F if given some protection. The foliage is often damaged with frost.
LIGHT
Full sun for best flowering; it will tolerate some shade with fewer flowers and more leggy growth
SALT
Moderate Salt Spray Tolerance – it will tolerate some spray, but it is best to have more protection such as a fence or building as an additional barrier behind the first row of plantings or the first dunes.
Poor Soil Salt Water Tolerance – it’s risky for this plant to be put in a site where any salt water flooding may be present and it will not tolerate irrigation with salt water.
SOIL
It prefers fertile, slightly acid soil in the pH range of 5.5 to 6.5, but it will grow on a wide variety of well-drained soils. High alkaline soils may cause some micronutrient deficiencies. Heavy clay soils may bring more root rot problems in excessively wet years.
WATERING
It has poor to moderate drought tolerance once established, so it will tend to look a little better and flower more with irrigation in dry spells. It doesn’t like wet feet.
PROPAGATION
Softwood tip cuttings in late spring/summer; under mist with a rooting hormone will root in 4 to 6 weeks; air layering done in the summer
PRUNING
Pinch to encourage bushiness and more flowers; prune as needed to control shape and size; excessive pruning reduces flowering; with freeze damaged plants, cut back to live wood after danger of additional freezes has passed
FERTILIZING
It has no special fertilizer needs. Unless a soil test suggests otherwise, a slow-release balanced analysis fertilizer with trace elements applied per the product label will work. Some scholars say that lower phosphorus amounts should be applied to prevent a buildup of phosphorus or phosphorus pollution – again, a soil test will help in that decision. Hibiscus plants are generally heavier feeders than some other plants.
PESTS
Saddleback Caterpillar - University of Florida
Brown Marmorated Stink Bug - University of Florida
Hibiscus Midge - University of Florida
Pink Hibiscus Mealybug - University of Florida
Melon Aphid or Cotton Aphid - University of Florida
Japanese Beetle - University of Florida
Citrus Longhorned Beetle - University of Florida
Fuller Rose Beetle - University of Florida
Leaffooted Bug - University of Florida
Papaya Mealybug - University of Florida
Blossom Midge - University of Florida
Io Moth - University of Florida
Root Knot Nematodes - Missouri Botanical Gardens
Black Thread Scale - University of Florida
Lobate Lac Scale - University of Florida
Soft Brown Scale, Coccus hesperidum - Weekend Gardener
Southern Red Mite - University of Florida
Hibiscus Erineum Mite - University of Florida
False Spider Mite - University of Florida
Red and Black Flat Mite - University of Florida
Greenhouse Whitefly - University of California
Sweetpotato Whitefly B Biotype of Silverleaf Whitefly - University of Florida
Bandedwing Whitefly - University of Florida
Melon Thrips - University of Florida
Brown Garden Snail - University of Florida
Longtailed Mealybug - University of Florida
DISEASES
Powdery Mildew - University of California
Downy Mildew - Purdue University
Xanthomonas Leaf Spot - University of Illinois
Armillaria Root Rot - University of Florida
Phytophthora Root Rot - North Carolina State University
Pythium Root Rot - Purdue University
Erwinia Root Rot - Lucid Central
Rhizoctonia Root Rot - Michigan State University
Sclerotium Root Rot (Southern Blight) - Alabama Cooperative Extension
Anthracnose - University of California
Bacterial Leaf Spot - University of Hawaii
Hollyhock Rust - Cornell University
Botrytis Blight or Gray Mold - Missouri Botanical Gardens
Fusarium - Missouri Botanical Gardens
DEER
Mostly tolerant, but occasional damage
Deer are obviously not a concern in the heart of the metropolis. Rural residents and those living in developed housing projects that are near large natural habitats may want to consider some protection if many deer have been seen in the area.
There are very few totally “deer-proof” plants. There are also, relatively speaking, few plants that are considered a preferred food supply of deer. Most plants fall in the big gap between. One of the biggest variables is the available preferred food supply in a given area. If their preferred food is scarce, they will munch on most anything.
OTHER
Good butterfly and hummingbird plant
USES
Specimen plant, tropical effect, tree standard, mass planting, foundation plant, containers, hedge – though flowering is reduced with excessive shearing
A search of California Poison Control, ASPCA, Texas A&M University, Canadian Poisonous Plants Information System, University of Wisconsin, Poisonous Houseplants and Ornamentals - Merck Vet Manual, Purdue University - Guide to Toxic Plants in Forages, Poisonous Plants of the Southeastern United States - Alabama Cooperative Extension, Florida Poison Control, and The Cat Fanciers Association did not show this plant on any of their lists.