Overview
Cosmos atrosanguineus is a perennial in the genus Cosmos, part of the Asteraceae family. Cosmos atrosanguineus grows best in full sun, and tolerates well-drained soils. Its UK hardiness is rated H4. Suggested uses include borders and containers. It is native to Mexico.
About
Cosmos atrosanguineus is a perennial in the Asteraceae grown for its scented flowers. Native to Mexico, it flowers from July to October. It prefers full sun, well-drained soil and moderate moisture and is rated H4 for UK hardiness (average winter hardiness). Suitable uses include borders and containers.
Wikipedia contributors, CC BY-SA 4.0 — Cosmos atrosanguineus
About the genus
Cosmos is a genus, with the same common name of cosmos, consisting of flowering plants in the daisy family.
Wikipedia contributors, "Cosmos (plant)", CC BY-SA 4.0 — Cosmos (plant)
In the garden
Cosmos atrosanguineus belongs to the Asteraceae and originates from Mexico, where it has long been cultivated for its fragrant blooms. In the UK it reliably produces flowers from July to October, bringing scent to the summer and autumn garden. Position it in a sunny spot on free-draining soil and avoid waterlogged ground; the plant requires only moderate soil moisture rather than constant wetness. The UK hardiness rating H4 translates to average winter hardiness across much of Britain, so in most areas it can be left in place through winter with no special insulation, though very exposed sites may be colder than its rating. Use Cosmos atrosanguineus where its floral scent will be appreciated: mixed summer borders and patio containers are both suitable. In containers choose a free-draining compost and ensure the pot does not sit in standing water. Its season of interest runs from mid-summer into autumn, giving gardeners a scented presence in borders or on terraces during July to October.
Growing conditions
Best soil and position for Cosmos
- Sunlight
- full sun
- Soil type
- well-drained
- Soil moisture
- moderate
- UK hardiness
- H4
Plant details
Cosmos atrosanguineus size, habit and characteristics
- Plant type
- perennial
- Suggested uses
- borders, containers
- Native to
- Mexico
- Fragrance
- Flower
Care notes
Pruning and caring for Cosmos atrosanguineus
- Cultivation
- Grow in well-drained soil in full sun. Protect from frost.
- Pruning
- Deadhead spent flowers to encourage more blooms.
- Propagation
- division, cuttings
Frequently asked questions
How do I grow Cosmos atrosanguineus?
Grow in well-drained soil in full sun. Protect from frost.
Where is the best place to plant Cosmos atrosanguineus?
Cosmos atrosanguineus prefers full sun.
What soil does Cosmos atrosanguineus need?
Cosmos atrosanguineus grows best in well-drained soil. Aim for soil that stays moderate.
How do I prune Cosmos atrosanguineus?
Deadhead spent flowers to encourage more blooms.
Is Cosmos atrosanguineus hardy in the UK?
Cosmos atrosanguineus has an RHS hardiness rating of H4, meaning it is hardy through an average UK winter, tolerating -10 to -5°C.
How do I propagate Cosmos atrosanguineus?
Division, cuttings.
