Menu

Plant Finder

aquatic

Swamp Rosemallow

Hibiscus grandiflorus

Add To My Wish List

print page
 
Swamp Rosemallow (Hibiscus grandiflorus) at Jolly Lane Greenhouse

Swamp Rosemallow flowers

Swamp Rosemallow flowers

(Photo courtesy of NetPS Plant Finder)

Height:  10 feet

Spread:  3 feet

Sunlight:  full sun  partial shade 

Hardiness Zone:  (annual)

Other Names:  Giant Rosemallow, Velvet Mallow, Swamp Hibiscus

Description:

This bold water friendly plant features large, felty, gray green leaves; grows quite tall, and is crowned with large pale pink blooms in summer; great for a garden that is kept moist until it is established, or in pondside areas; do not allow to dry out

Ornamental Features

Swamp Rosemallow features bold white star-shaped flowers with shell pink overtones and crimson eyes at the ends of the stems from late spring to early fall. Its large tomentose lobed leaves remain grayish green in color with curious gray undersides throughout the year. The fruit is not ornamentally significant.

Landscape Attributes

Swamp Rosemallow is an herbaceous annual with a rigidly upright and towering form. Its relatively coarse texture can be used to stand it apart from other garden plants with finer foliage.

This plant will require occasional maintenance and upkeep, and is best cleaned up in early spring before it resumes active growth for the season. It is a good choice for attracting butterflies and hummingbirds to your yard. Gardeners should be aware of the following characteristic(s) that may warrant special consideration;

  • Insects
  • Self-Seeding

Swamp Rosemallow is ideally suited for growing in a pond, water garden or patio water container, and is recommended for the following landscape applications;

  • Accent
  • Mass Planting
  • General Garden Use
  • Water Gardens
  • Naturalizing And Woodland Gardens
  • Container Planting
  • Bog Gardens

Planting & Growing

Swamp Rosemallow will grow to be about 10 feet tall at maturity, with a spread of 3 feet. It has a low canopy with a typical clearance of 1 foot from the water. Although it's not a true annual, this fast-growing plant can be expected to behave as an annual in our climate if left outdoors over the winter, usually needing replacement the following year. As such, gardeners should take into consideration that it will perform differently than it would in its native habitat.

This plant does best in full sun to partial shade. As an aquatic plant, it requires a suitable water garden environment and will benefit from special planting and ongoing care practices; consult one of our in-store experts for further details and instructions. It is not particular as to soil type or pH, and is able to handle environmental salt. It is highly tolerant of urban pollution and will even thrive in inner city environments. Consider applying a thick mulch around the root zone in winter to protect it in exposed locations or colder microclimates. This species is native to parts of North America.

Swamp Rosemallow is a fine choice for the water garden, but it is also a good selection for planting in outdoor pots and containers. Its large size and upright habit of growth lend it for use as a solitary accent, or in a composition surrounded by smaller plants around the base and those that spill over the edges. Note that when grown in outdoor pots and containers, aquatic plants like this one will require a special growing environment that meets their requirement for consistent moisture.

 
 
Hardiness Zone Plant Height Minimum Sunlight
Characteristics
Accent  Massing  Garden  Naturalizing  Container  Bog  Water 
Applications
Flowers  Texture  Attracts Wildlife 
Ornamental Features