Marsh Grass of Parnassus (Parnassia palustris)

Marsh Grass of Parnassus

Parnassia palustris

Delicate white blooms rise above wetland foliage, a quiet wetland gem. Perennial herbaceous wildflower; common name: Marsh Grass of Parnassus.

Partial sun
2–3/week
Moderate
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Plant Needs

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Sunlight Prefers partial sun to full shade; tolerates full sun only in cool, moist climates to prevent leaf scorch
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Watering Keep soil consistently moist, mimicking natural wetland conditions; avoid drying out completely
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Temperature Hardy to -20°C; tolerates cool summer temperatures, avoid prolonged heat over 25°C
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Characteristics

  • Leaf: Basal rosette of rounded, glossy green leaves; single stem leaf clasping the lower stem
  • Flower: Star-shaped white blooms with green veining on petals; central nectar glands fringed with tiny hairs
  • Stem: Slender, upright green stems with no branching
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Care Guide

Watering

Keep substrate constantly moist, avoid waterlogging but do not let dry out

Fertilization

Diluted balanced feed once every 6 weeks. Avoid over-fertilizing to prevent lush foliage at the expense of blooms

Composted banana peel tea:Compost banana peels fully, dilute 1:20 for root drench; apply only in early spring to support flowering
Pruning
  • Remove spent blooms to prevent self-seeding if desired
  • Trim back dead foliage in late autumn after frost
  • Thin overcrowded clumps in early spring to improve airflow
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Toxicity

Warning: this plant may be toxic.

Pets & Humans

Pets: ASPCA: No listed toxicity to cats

Humans: No known toxicity to humans

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Garden Uses & Culture

Culture: N/A

Usage: Ornamental bog garden plant; wildlife nectar source for bees and butterflies