Airy ferny plants topped by simple daisies that wave on tall stems and adore poor, dry soil. One of the easiest cut flowers from seed, loved by bees and butterflies.
At a glance
- Plant type: Annual
- Mature size: 1.2 m H × 40 cm W
- Aspect: full sun
- Water: happy on low water
- Frost: tender
- Maintenance: low maintenance
- Origin: Exotic
About Cosmos
Botanically, Cosmos bipinnatus is an fast-growing annual in the Asteraceae family. It reaches around 1.2 m tall and 40 cm wide at maturity, with deciduous foliage. Pink, white and purple flowers appear for much of the year.
Where to grow Cosmos
Cosmos suits warm-temperate, subtropical and Mediterranean climates and grows best in full sun. It is frost tender, so protect it from hard frosts or grow it in a sheltered spot or pot. It also is a genuinely water-wise choice.
Soil & planting
Most soils suit Cosmos provided drainage is reasonable. Plant into well-prepared ground, firm the soil around the roots and water deeply to settle it in.
Watering & feeding
Cosmos is happy on low water, so once its roots are down it needs little supplementary water. A feed in spring with a balanced fertiliser keeps growth strong. In its first year, water deeply once or twice a week to settle the roots in, then taper off as it establishes.
Pruning & care
Prune Cosmos after flowering to keep it compact and encourage the next flush of blooms. Overall it is low maintenance.
Using Cosmos in the garden
Cosmos earns its place for cut flowers for the vase, feeding bees and pollinators, attracting butterflies and a feature or specimen planting.
Companion planting & design
For a cohesive, low-care bed, pair Cosmos with other plants that enjoy the same happy on low water and warm-temperate climate. Repeat it through a border to tie the planting together and give a sense of rhythm.
Good to know
It is regarded as non-toxic and pet-safe.
Buying Cosmos
Plant Sale lists Cosmos as seed. Stock isn't live yet — register your interest using the panel above and we'll email you the moment we have it ready.
Prefer to grow it yourself? See the Cosmos seed sowing guide for depth, timing and germination.