Long-bristled Smartweed (Persicaria longiseta)

Long-bristled Smartweed

Persicaria longiseta

Slender, delicate spikes carry tiny pink blooms, a quiet meadow beauty. Annual or short-lived perennial herb; common name: Long-bristled smartweed.

Full sun
1–2/week
Beginner
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Plant Needs

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Sunlight Full to partial sun; tolerates light shade but produces the most blooms in direct sunlight
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Watering Water regularly to keep soil evenly moist; avoid prolonged drought stress during hot growing periods
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Temperature Hardy to mild frosts; thrives in temperate to warm growing conditions between 15–28°C
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Characteristics

  • Leaf: Lanceolate to ovate leaves with smooth margins, pointed tips, and short petioles
  • Flower: Tiny pink to pale rose flowers arranged in dense, slender terminal spikes with long bristles at calyx bases
  • Stem: Slender, branching stems with swollen nodes characteristic of the Polygonaceae family
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Care Guide

Watering

Keep soil consistently moist; water when the top 1 cm of soil feels dry

Fertilization

Diluted balanced liquid feed every 2 weeks. Cease fertilization in late autumn as growth slows

Composted banana peel tea:Steep fully composted banana peels in water for 24 hours, dilute 1:20 for root drench; avoid raw peels to prevent pest attraction
Pruning
  • Deadhead spent flower spikes to encourage extended blooming through early autumn
  • Trim back overgrown stems to maintain compact, tidy growth
  • Remove yellowing or damaged foliage to improve airflow and reduce disease risk
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Toxicity

Warning: this plant may be toxic.

Pets & Humans

Pets: ASPCA: No listed toxicity to cats

Humans: No documented toxic effects for humans

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Garden Uses & Culture

Culture: N/A

Usage: Ornamental ground cover; nectar source for bees and butterflies