Cosmos
Cosmos bipinnatus
In a typical UK garden, sow indoors early March to late March, sow outside late April to early June, plant out late April to late May, and harvest late June to late October.
When to sow, plant and harvest
Last frost around 20 April, first frost around 31 October.
- Sow indoors
- early March to late March
- Sow outdoors
- late April to early June
- Plant out
- late April to late May
- Harvest
- late June to late October
Growing facts
- Spacing
- 30 cm apart, rows 45 cm apart
- Square foot
- 1 per square (30 cm squares)
- Sowing depth
- 0.5 cm
- Ready in
- 40 to 60 days from planting out
- Grows to
- 1 m
- Hardiness
- Tender: killed by any frost
- Sun
- Full sun
- Crops for
- About 12 weeks
Growing tip
Don't feed them or grow them in rich soil, which gives tall, leafy plants with few flowers. Deadhead to keep them blooming.
Neighbours
Flowers are one crop rotation group. Try not to grow them where any of the family grew in the last two or three years. How crop rotation works
More flowers
Where these figures come from
Every crop in VegLog was checked against published growing advice. Dates are worked out from average frost dates, so they shift with your garden. For cosmos, we used:
Grow cosmos with VegLog
Add cosmos to a bed and VegLog reminds you when to sow, plant out and pick, timed to your own town's frost dates.
