Flowers · Seeds
Cosmos
Cosmos bipinnatus
A half-hardy annual with fine leaves and pink, white or crimson daisies from midsummer until frost. It flowers more, not less, in soil that is not heavily fed.
Growing conditions
Soilloam, sand, chalk
Moisturewell-drained
pHneutral, alkaline
Position
SunFull sun
Aspecteast, south, west
Exposuresheltered
HardinessH3
Size
Time to maturityFlowers about 12 weeks from sowing
Max height0.8–1.2 m
Max spread0.4–0.5 m
In the garden
Sow indoors in mid-spring and plant out after frost, or sow direct in late spring in a warm garden. Stake tall forms if the site is windy.
Slugs take young plants. Aphids sometimes gather on the soft tips.
Colour and scent
A mark in a season means the plant is doing that for at least part of it.
| Season | Foliage | Flower | Scent |
|---|---|---|---|
| Spring | — | — | — |
| Summer | Leaves | pink | — |
| Autumn | Leaves | pink | — |
| Winter | — | — | — |
- JanDormant
- FebDormant
- MarDormant
- AprDormant
- MayDormant
- JunFoliage
- Julpink
- Augpink
- Seppink
- Octpink
- NovDormant
- DecDormant
Jobs
These dates suit a mild southern garden. A northern or Scottish plan shifts spring and autumn jobs by a fortnight.
15 April
Sow indoors
Sow cosmos in trays in mid-spring and pot the seedlings on before they get leggy.
25 May
Plant out
Plant cosmos after the last frost, 40 cm apart, in the sunniest bed.
15 August
Deadhead
Snip off faded daisies weekly so the plants keep flowering into autumn.