Overview
Cirsium altissimum is a plant with a clump-forming perennial habit in the genus Cirsium, part of the Asteraceae family, with spiny, deeply lobed leaves foliage. Cirsium altissimum grows best in full sun, and tolerates loam soils and neutral pH. Its UK hardiness is rated H7. Suggested uses include wildlife gardens, borders and meadows.
About
Cirsium altissimum is a North American species of plants in the tribe Cardueae within the family Asteraceae. Common names are tall thistle or roadside thistle.
Wikipedia contributors, CC BY-SA 4.0 — Cirsium altissimum
About the genus
Cirsium is a genus of perennial and biennial flowering plants in the Asteraceae, one of several genera known commonly as thistles. They are more precisely known as plume thistles. These differ from other thistle genera in having a seed with a pappus of feathered hairs on their achenes.
Wikipedia contributors, "Cirsium", CC BY-SA 4.0 — Cirsium
Growing conditions
Best soil and position for Cirsium
- Sunlight
- Full sun
- Soil type
- Loam
- Soil pH
- Neutral
- Soil moisture
- Moist but well-drained
- Aspect
- South-facing
- Exposure
- Sheltered
- UK hardiness
- H7
Plant details
Cirsium altissimum size, habit and characteristics
- Habit
- Clump-forming perennial
- Foliage
- Spiny, deeply lobed leaves
- Suggested uses
- Wildlife gardens, borders, meadows
Care notes
Pruning and caring for Cirsium altissimum
- Propagation
- Seed, division
- Pest resistance
- Generally pest-free
- Disease resistance
- Powdery mildew
Frequently asked questions
Where is the best place to plant Cirsium altissimum?
Cirsium altissimum prefers full sun. It suits sheltered positions.
What soil does Cirsium altissimum need?
Cirsium altissimum grows best in loam soil. It prefers neutral soil. Aim for soil that stays moist but well-drained.
Is Cirsium altissimum hardy in the UK?
Cirsium altissimum has an RHS hardiness rating of H7, meaning it is fully hardy throughout the UK, tolerating temperatures below -20°C.
How do I propagate Cirsium altissimum?
Seed, division.
