Introducing...
Cosmos
Botanical name: Cosmos
Both the perennial Cosmos atrosanguineus and the annual cosmos are upright plants, making excellent additions to a summer border. The annuals are particularly effective when massed and provide flowers for cutting over a period of months. Annual comos are easily grown from seed.
Looks
Annuals have feathery leaves and saucer-like, white, pink, red, orange or yellow flowers. In some, the petals fuse to form an open cup. Cosmos atrosanguineus has dark red, chocolate-scented flowers.
Likes
Cosmos grow in most ordinary garden soils, provided they aren't soggy in summer, in full sun.
Dislikes
Very dry, poor soils and heavy, wet soils are unsuitable. Plants will not flower in shade.
Did you know?
Cosmos atrosanguineus is not reliably hardy. To ensure its survival over winter, cover the base of the plant with 15cm (6in) layer of straw or other dry material.
Growing guide
How to grow cosmos
All the information you will need to know to grow and care for annual cosmos can be found in the RHS Guide to annuals and biennials.
Cosmos we recommend
Cosmos bipinnatus 'Sensation Pinkie' (Sensation Series)
cosmea 'Sensation Pinkie'
- 0.5–1 metres
- 0.1–0.5 metres
Cosmos atrosanguineus
chocolate cosmos
- 0.5–1 metres
- 0.1–0.5 metres
Cosmos bipinnatus 'Rubenza'
cosmea 'Rubenza'
- 0.5–1 metres
- 0.1–0.5 metres
Cosmos bipinnatus 'Sensation Pinkie' (Sensation Series)
cosmea 'Sensation Pinkie'
- 0.5–1 metres
- 0.1–0.5 metres
Cosmos atrosanguineus
chocolate cosmos
- 0.5–1 metres
- 0.1–0.5 metres
Cosmos bipinnatus 'Rubenza'
cosmea 'Rubenza'
- 0.5–1 metres
- 0.1–0.5 metres
Useful advice
Hardy annuals: sowing in spring
Tender perennials: cuttings
Get involved
The Royal Horticultural Society is the UK’s leading gardening charity. We aim to enrich everyone’s life through plants, and make the UK a greener and more beautiful place.