Slender-headed Sowthistle (Sonchus leptocephalus)

Slender-headed Sowthistle

Sonchus leptocephalus

Its delicate yellow blooms add soft wild charm to meadows. Annual herbaceous wildflower; common name: Slender-headed Sowthistle.

Full sun
1/week
Beginner
🌱

Plant Needs

☀️
Sunlight Full sun to partial shade; performs best in open, sunny meadow conditions
💧
Watering Water deeply when the top 2–3 cm of soil is dry; drought-tolerant once established
🌡️
Temperature Thrives in 15–25°C; tolerates light spring frost down to 5°C
🔍

Characteristics

  • Leaf: Basal rosette of lobed, spiny-margined leaves; stem leaves clasp the stem at the base
  • Flower: Bright yellow composite flower heads (1–2 cm diameter) clustered at upper stem tips
  • Stem: Erect, branched, slightly hairy, with milky, bitter-tasting sap
🛠️

Care Guide

Watering

Water occasionally during prolonged dry spells; avoid overwatering to prevent root rot

Fertilization

Optional diluted organic feed once monthly if soil is very poor. Avoid high-nitrogen fertilizers to prevent excessive leaf growth at the expense of blooms

Eggshell powder top-dress:Crush dried eggshells into fine powder; sprinkle lightly on the soil surface to boost calcium levels without burning shallow roots
Pruning
  • Deadhead spent flower heads to extend the flowering period by 2–3 weeks
  • Remove yellowing basal leaves to improve airflow and reduce pest habitat
  • Cut back the entire plant to ground level after seed set to control self-seeding if desired
⚠️

Toxicity

Warning: this plant may be toxic.

Pets & Humans

Pets: ASPCA: Non-toxic to cats

Humans: Non-toxic; young leaves are edible when cooked to reduce bitterness

📖

Garden Uses & Culture

Culture: N/A

Usage: Edible young leaves (cooked to reduce bitterness); wildflower ornamental for pollinator gardens