Introduction

The scarlet rosemallow is a narrow, upright, herbaceous perennial that can reach a height of 4 to 8 feet. The 5- to 6-inch-long leaves of this plant are palmately lobed into 3, 5, or 7 parts. These finger-like lobes are slender and have jagged teeth along their margins. Deep red flowers that are 5 to 6 inches wide appear in mid to late summer. These flowers are funnel form and occur on long axillary peduncles. There are 10 or more involucral bracts present on the flower. They are curved upward and are much shorter than the calyx lobes.

General Information

Scientific name: Hibiscus coccineus

Pronunciation: hye-BISS-kus kock-SIN-ee-us

Common name(s): scarlet rosemallow, Texas star hibiscus, swamp hibiscus

Family: Malvaceae

Plant type: perennial; herbaceous

USDA hardiness zones: 8 through 10 (Figure 3)

Planting month for zone 8: year-round

Planting month for zone 9: year-round

Planting month for zone 10 and 11: year-round

Origin: native to Florida

Invasive potential: not known to be invasive

Uses: accent; border; mass planting; attracts butterflies; attracts hummingbirds

Availability: somewhat available, may have to go out of the region to find the plant

Description

Height: 4 to 8 feet

Spread: 3 to 4 feet

Plant habit: upright

Plant density: open

Growth rate: fast

Texture: fine

Foliage

Leaf arrangement: alternate

Leaf type: simple

Leaf margin: lobed; serrate

Leaf shape: star-shaped

Leaf venation: palmate

Leaf type and persistence: deciduous

Leaf blade length: 4 to 8 inches

Leaf color: green

Fall color: no fall color change

Fall characteristic: not showy

Flower

Flower color: red

Flower characteristic: summer flowering

Fruit

Fruit shape: elongated

Fruit length: 1/2 to 1 inch

Fruit cover: dry or hard

Fruit color: unknown

Fruit characteristic: inconspicuous and not showy

Trunk and Branches

Trunk/bark/branches: typically, multi-trunked or clumping stems

Current year stem/twig color: reddish

Current year stem/twig thickness: very thick

Culture

Light requirement: plant grows in part shade/part sun

Soil tolerances: extended flooding; acidic; sand; loam; clay

Drought tolerance: moderate

Soil salt tolerances: poor

Plant spacing: 24 to 36 inches

Other

Roots: not applicable

Winter interest: no special winter interest

Outstanding plant: plant has outstanding ornamental features and could be planted more

Pest resistance: very sensitive to one or more pests or diseases which can affect plant health or aesthetics

Use and Management

The scarlet rosemallow is frequently used as a specimen and can be placed in a border. It may also be utilized around the edge of a pond or along a stream since this type of site is similar to their native Georgia and Florida habitat.

Although the scarlet rosemallow is native to wetland areas it is tolerant of somewhat drier soils. This plant requires a full sun or partial shade location in the landscape. Flowering and growth in the shade are poor.

Cultivars include: 'Lord Baltimore', deep red flowers.

Hibiscus coccineus can be propagated by seed or division.

Pest and Diseases

The scarlet rosemallow may be occasionally bothered by a stalk borer. Grasshoppers also enjoy chewing the foliage and flower buds. This can spoil the flower display. Be prepared to provide control for this pest. I usually squash them between my hands in the evening as a means of mechanical control.