Hemlock Water Dropwort (Oenanthe crocata)

Hemlock Water Dropwort

Oenanthe crocata

Deadly toxic yet visually delicate, with feathery foliage and umbel flowers. Perennial aquatic herb; common name: hemlock water dropwort.

Partial sun
continuous/week
Moderate
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Plant Needs

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Sunlight Prefers partial shade to full sun; thrives in wet, boggy or pond-edge conditions
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Watering Requires constant moisture or shallow standing water up to 30 cm deep; do not allow soil to dry out
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Temperature Hardy to mild frosts; prefers cool to temperate temperatures; avoid extreme heat above 28°C
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Characteristics

  • Leaf: Bright green, pinnately compound, feathery, fern-like leaflets
  • Flower: Tiny white flowers arranged in flat-topped umbels
  • Stem: Hollow, succulent, green to purplish stems with distinct sheaths at nodes
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Care Guide

Watering

Maintain consistent shallow standing water or saturated substrate

Fertilization

Diluted aquatic plant feed every 2 weeks. Avoid over-fertilizing to prevent algal blooms in standing water habitats

Composted banana peel tea:Compost banana peels fully to eliminate odor; dilute 1:20 for root drench; avoid direct contact with stems to prevent rot
Pruning
  • Remove yellowing foliage promptly to maintain plant health and prevent decay
  • Trim overgrown stems to control spread in managed pond edges
  • Cut back spent flower heads to limit self-seeding in controlled habitats
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Toxicity

Warning: this plant may be toxic.

Pets & Humans

Pets: ASPCA-listed toxic; ingestion causes severe neurological symptoms and potential death

Humans: Contains cicutoxin, a potent neurotoxin; ingestion can cause seizures, respiratory failure, and fatalities

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Garden Uses & Culture

Culture: N/A

Usage: N/A