Swamp Rosemallow (Hibiscus palustris)

Swamp Rosemallow

Hibiscus palustris

Its pink blooms rise like watercolor clouds over wetlands. Herbaceous perennial wildflower; common name: Swamp Rosemallow.

Full sun
2–3/week
Moderate
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Plant Needs

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Sunlight Full sun to partial shade; thrives in bright direct sunlight for most of the day, with partial shade tolerated in hot, arid climates
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Watering Keep soil consistently moist, as it prefers wetland conditions; avoid allowing the root zone to dry out completely
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Temperature Hardy to USDA zone 4; tolerates cold winter temperatures and hot, humid summer conditions
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Characteristics

  • Leaf: Broad heart-shaped to ovate leaves with serrated margins; medium green, slightly fuzzy texture
  • Flower: 10–15 cm wide pink to rose-pink blooms with prominent yellow staminal columns
  • Stem: Erect, hairy green stems with branching near the upper growth nodes
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Care Guide

Watering

Keep soil continuously moist; apply mulch to retain moisture and regulate soil temperature

Fertilization

Apply a balanced organic feed once at the start of growing season. Avoid over-fertilizing to prevent excessive foliage growth at the expense of flowering

Composted banana peel tea:Steep fully composted banana peels in water for 24 hours; dilute the mixture 1:20 with water for root drenching to avoid nutrient burn
Pruning
  • Deadhead spent blooms regularly to encourage extended flowering through the growing season
  • Cut back stems to ground level in late autumn after the first frost to prepare for winter dormancy
  • Thin crowded stems in early spring to improve airflow and light penetration for healthier growth
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Toxicity

Warning: this plant may be toxic.

Pets & Humans

Pets: ASPCA: Toxic; contains cyanogenic glycosides in leaves, flowers, and stems, leading to gastrointestinal and neurological symptoms

Humans: Ingestion of large amounts may cause mild gastrointestinal upset, including nausea and diarrhea

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Garden Uses & Culture

Culture: N/A

Usage: Ornamental wetland plant; provides nectar for bees, butterflies, and hummingbirds