Cotton thistle (Onopordum acanthium) is a plant in the annuals and biennials category that can grow 3m – 8m tall and 50cm – 1.5m wide.
This plant has several common names including: cotton thistle, Argentine thistle, down thistle, giant thistle, musk thistle, oak thistle, oat thistle, Queen Mary’s thistle, Scotch thistle, Scots thistle, silver thistle, star thistle or thistle-upon-thistle.
This is a deciduous plant that takes 2-5 years to reach full maturity.
Plant profile
Common name: cotton thistle, Argentine thistle, down thistle, giant thistle, musk thistle, oak thistle, oat thistle, Queen Mary’s thistle, Scotch thistle, Scots thistle, silver thistle, star thistle, thistle-upon-thistle
Scientific name: Onopordum acanthium
Plant type: Annual / Biennial
Habit: Bushy
Height: 3m – 8m
Spread: 50cm – 1.5m
Foliage: Deciduous
Sunlight: Full Sun
Soil: Chalk, Loam, Sand
Moisture: Well drained
Garden type: Informal Garden, Wildflower meadow
Planting type: Flower borders and bedding
Other characteristics: Plants for pollinators
Seasonal colors
| Season | Stem | Foliage | Flower | Fruit |
|---|---|---|---|---|
| Spring | ||||
| Summer | ||||
| Autumn | ||||
| Winter |
How to plant Cotton thistle (Onopordum acanthium) – Agnieszka Kwiecień, Nova, CC BY-SA 4.0, via Wikimedia Commons
Cultivation profiles – Growing Cotton thistle (Onopordum acanthium) – Stefan.lefnaer, CC BY-SA 4.0, via Wikimedia Commons
