The Swamp Hibiscus (Hibiscus moscheutos pronounced as hy-BISS-kus moe-SHOO-tos) is a vigorous perennial with thick, succulent stems reaching the hight of 5 – 6 feet and forming 3-foot-wide clumps. The name comes from its fragrance, suggesting the musk-rose.
The spectacular, funnel-shaped 8 to 10-inch-wide flowers with a prominent central column come in red, pink, white, or bi-color. It blooms from midsummer through fall. Although individual flowers last only for one or two days, hundreds are produced, so the plant is almost constantly in flower.
Blossoms are loaded with nectar and pollen, and hummingbirds are frequent visitors.4 In tropical areas, swamp mallows are popular as hedges. This is an easy to grow plant with moderate water and fertilizer requirements which does best in full sun and partial shade. It will also tolerate wetlands and creek edges and is useful in poorly drained soils.3
The Swamp Hibiscus is slow to emerge in spring, so do not be alarmed if you see little sign of life until the warmth of early summer. It grows so quickly that by late summer it is hard to believe that such large shrubby plants are truly herbaceous. It is easy to start from seeds or to propagate from division.
Japanese beetles are its major pest problem. They devour both leaves and flowers. Most of the swamp mallows available from nurseries are hybrids. Breeders have crossed the red-flowered Scarlet rosemallow (H. coccineus) with the hardier Halberd-leaf rosemallow (H. laevis), and Swamp rose mallow (H. moscheutos) to get the outrageous dinner plate hybrids with flowers nearly a foot across.5 Some cultivars grow only 3 to 4 feet tall.
- Other names: Swamp Rosemallow, Swamp Mallow, Common Rose Mallow, Perennial Hibiscus, Marshmallow, Hardy hibiscus
- Family: Malvaceae (Mallow)
- Native to: Southern United States
- Howard Garrett – Plants for Houston And The Gulf Coast
- Frances Tenenbaum – Taylor’s Encyclopedia of Garden Plants
- Leah Chester-Davis, Toby Bost – The Successful Gardener Guide: North Carolina
- Marie Harrison – Flowering Shrubs and Small Trees for the South
- William Cullina – The New England Wild Flower Society Guide to Growing and Propagating