Cabbage Thistle (Cirsium oleraceum)

Cabbage Thistle

Cirsium oleraceum

Its spiky foliage holds soft yellow blooms like sunny stars. Herbaceous perennial; common name: Cabbage Thistle

Full sun
1–2/week
Beginner
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Plant Needs

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Sunlight Full sun to partial shade; tolerates dappled sunlight to prevent leaf scorch in warm climates
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Watering Water deeply when the top 5 cm of soil dries out; tolerates short periods of drought once established
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Temperature Hardy to -20°C for cold winter survival; avoid prolonged exposure to temperatures above 35°C
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Characteristics

  • Leaf: Basal rosette of spiny, oblong leaves with wavy margins; upper leaves clasp stems
  • Flower: Round, bright yellow composite flower heads (2–5 cm diameter) clustered at stem tops
  • Stem: Erect, hairy stems with spiny wings running lengthwise
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Care Guide

Watering

Keep soil consistently moist during active growth periods

Fertilization

Diluted balanced liquid feed once monthly. Skip fertilization in autumn and winter when growth slows

Banana peel compost tea:Compost banana peels for 2–3 weeks, steep in water for 24 hours, dilute 1:20 for root drench to avoid nutrient burn
Pruning
  • Deadhead spent flower heads to encourage prolonged summer blooming
  • Cut back stems to the basal rosette in late autumn to prepare for winter dormancy
  • Remove damaged or diseased foliage promptly to reduce fungal infection risk
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Toxicity

Warning: this plant may be toxic.

Pets & Humans

Pets: ASPCA: No documented toxicity to cats

Humans: No known toxicity to humans; young leaves are safe to eat when cooked

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Garden Uses & Culture

Culture: N/A

Usage: Edible cooked young leaves; pollinator-friendly ornamental for wildflower gardens