Trailing St John's-wort (Hypericum humifusum)

Trailing St John's-wort

Hypericum humifusum

It trails low across gravel, dotted with sunny yellow blooms. Prostrate perennial herb; common name: Trailing St John's-wort.

Full sun
1–2/week
Beginner
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Plant Needs

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Sunlight Full sun to partial shade; thrives in bright, direct sunlight in temperate regions, tolerates light shade during hot summer afternoons
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Watering Water when the top 2–3 cm of soil is completely dry; tolerate short periods of drought, avoid overwatering to prevent root rot
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Temperature Hardy to -10°C, suitable for temperate climates; avoid prolonged temperatures above 35°C which can cause leaf scorch
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Characteristics

  • Leaf: Opposite, oblong to oval, pale green, sessile with translucent oil glands
  • Flower: Bright yellow, 5-petaled, with dense clusters of golden stamens; 1–2 cm in diameter
  • Stem: Slender, trailing, reddish-green, rooting at nodes to form dense mats
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Care Guide

Watering

Keep soil evenly moist but not waterlogged; increase frequency during prolonged dry spells

Fertilization

Light top-dressing of compost if soil is nutrient-poor. Avoid high-nitrogen fertilizers which can promote leggy, weak growth

Crushed eggshell powder top-dressing:Sprinkle a thin layer of finely crushed eggshells on the soil surface in early spring to improve soil structure and add calcium
Pruning
  • Trim back dead or damaged foliage in early spring to encourage new growth
  • Pinch off spent flowers to prolong the blooming period
  • Thin overcrowded stems to improve air circulation and reduce disease risk
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Toxicity

Warning: this plant may be toxic.

Pets & Humans

Pets: ASPCA notes Hypericum species may cause mild gastrointestinal upset and increased photosensitivity if ingested

Humans: Mild gastrointestinal upset if ingested in large quantities; may cause photosensitivity in sun-exposed skin for sensitive individuals

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Garden Uses & Culture

Culture: N/A

Usage: Ground cover for rock gardens, container trailing plant, and wildflower meadow addition