Hibiscus moscheutos, more commonly referred to as the Swamp Rosemallow, Swamp Mallow, or simply as the Hardy Hibiscus, is a vibrant perennial shrub.
It stands out for its large, pink, or white showy flowers.
Gardeners like to grow this type of Hibiscus plant for its dramatic blooms and its hardiness. It is also great for attracting pollinators such as butterflies and hummingbirds to the garden.
This hardy Hibiscus plant reaches a height of 4 to 7 feet (1.2 to 2 meters), with a spread of 2.5 to 3 feet (75 to 90 cm).
The foliage of Swamp Mallow Hibiscus consists of slightly hairy, large green leaves. These are ovate to lance-shaped and make a great backdrop for its blossoms, which bloom from mid-summer to early fall.
The flowers are large and disc-shaped, and naturally range in color from white to pink, with many red cultivars available.
The plant is native to the wetlands and riverbanks of southern and eastern regions of the United States, and performs well in USDA growing zones 5 to 9. This makes it hardy down to about -20°F (-29°C).
In the garden, it can be an excellent choice for water gardens, growing along pond edges, or for use in large containers.
How to Grow Swamp Mallow in the Garden
Locate in a sunny spot, that has a moist, well-drained soil that is fairly fertile. It is great plant to grow in areas of your garden that are damp.
Once established, Swamp Mallow requires regular watering to keep the soil consistently moist. Do not let the soil get waterlogged as this plant can get root-rot. To help prevent this add organic matter to the soil to help improve drainage.
Provide an annual application of a balanced fertilizer in early spring/ This will encourage healthy growth and prolific blooming.
While generally a robust plant that is easy to care for, it can sometimes be affected by aphids and whiteflies. Be on the lookout for these pests, and remove them before they have a chance to become an issue.
Pruning your Swamp Mallow in late winter or early spring should help it to maintain a compact form, and will also encourage strong growth. Remember, though, that all parts of the plant are considered poisonous if ingested, so handle with care.
There are several methods to propagate Hibiscus moscheutos including sowing seeds, taking cuttings, or through division.
To get a head-start to the blooming season, seeds can be started indoors 10 to 12 weeks before the last expected frost. Sow into a well-draining soil. Stratify first to enhance germination rates.
Seeds can also be sown directly outdoors once the soil has warmed up (stratify seeds), and the last chance of a frost has passed. Seeds can also be winter sown in containers.
Semi-hardwood cuttings can be taken in summer and rooted in a moist medium. Or divide mature plants in spring or fall.
Quick Swamp Hibiscus Growing and Care Guide
Scientific Name: Hibiscus moscheutos
Common Name(s): Swamp mallow, Swamp Hibiscus, Hardy Hibiscus, Rose Mallow, Eastern rosemallow.
Growing Zone (USA / UK Hardiness): USDA Zones: 5-10. RHS Hardiness Rating equivalent: H5 (Hardy – cold winter).
Best Used For / Garden Location: Ideal for damp parts of the garden, boggy areas, and pond edges. Though it likes damp areas, it does not like waterlogged areas as it can be subject to root rot.
Plant Details
Life Cycle / Plant Type: Herbaceous, perennial.
Plant Height: 4-7 feet (1.2-2.1 m).
Plant Spread: 2-4 feet (0.6-1.2 m).
Blooms: Summer.
Flower Details: Flowers are large, showy, with five petals. These may be pink, white, or red.
Leaf Foliage: The leaves are alternate, ovate to lanceolate, dark green.
Fruit: Seed capsules.
Growing Conditions and Location
Best Light Conditions: Full sun (for best results) to part shade.
Suitable Soil Types: Prefers wet, well-drained, neutral to slightly acidic soil.
Sowing / planting: Sow seeds in spring, propagate by cuttings in summer, or divide in spring or fall.
Germination time: Seeds germinate in 2-3 weeks.
Propagation: Propagation can be done by seeds or cuttings.
Plant Care: Deadhead regularly for continued bloom. Cut back in late fall.
Growing in pots and containers: Can be grown in containers.
Growing as a House plant: Not typically grown as a houseplant.
Further Information
Miscellaneous: Attracts hummingbirds and butterflies. Fairly deer resistant.
Pests and diseases: Japanese beetles, aphids, and fungal diseases.
Common Cultivars / Varieties: Hibiscus moscheutos 'Southern Belle' has large red or pink flowers. 'Fireball', bright red blooms. 'Copper king', Copper-red flowers. 'Lord Baltimore, Bright red flowers with ruffled petals.'Lady Baltimore', Pink flowers with red center. 'Midnight Marvel', Dark, almost black foliage – deep red flowers.'Kopper King', maple-like foliage with pale pink flowers that have a red center.
Family: Malvaceae, the Mallow family.
Native: North America.
References and Further Reading: Missouri Botanical Garden Plant Finder: Hibiscus moscheutos; Washington College guide to Swamp Rose Mallow (includes information on uses in edible applications)
Common Questions
Does Hibiscus moscheutos make a good garden or landscaping plant?
Hibiscus moscheutos can be a fantastic addition to a garden, especially when grown in the vicinity of a water feature.
Is it a fragrant plant?
Hibiscus moscheutos is not known for being a fragrant plant. It is grown for its large, attractive flowers, rather than for any notable aroma.
What is the perfect location to grow Swamp Mallow?
Swamp Mallow prefers to grow in full sun and in moist, well-drained soil. It is a perfect plant for waterside planting due to its love of water.
Is Hibiscus moscheutos invasive in the USA?
Hibiscus moscheutos is native to USA wetland is not considered invasive.
How do I remove Swamp Mallow from my garden?
Removal involves cutting the plant back and digging out the root system. For an easier time, do this in late winter or early spring before any new growth has begun.
Summary
Hibiscus moscheutos is a North American native that is commonly known as the Swamp Mallow or Hardy Hibiscus. Plants bloom in the summer and early autumn with disc shaped flowers.
They do best when grown in full sun, and prefer a consistently moist to wet soil. They make a nice plant to grow for waterside planting and rain gardens.
I hope that you have enjoyed reading this guide on how to grow Swamp Mallow. You may also enjoy the following growing guides: How to grow Rose of Sharon, the Hyssopus Plant, Thunbergia, and Impatiens plants in the garden.
