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FlowersHalf-HardyAnnual
Cosmos
Cosmos is a free-flowering half-hardy annual grown for airy foliage and long-lasting daisy-like flowers in white, pink, crimson and orange shades. It is one of the most useful summer fillers for borders and cutting gardens, flowering over a long season if kept picked.
Basic information
Category
Flowers
Lifecycle
Annual
Hardiness
Half-Hardy
Planting partners
0 companions · 0 crops to avoid
Growth profile
Germination window
7–14 days
Germination temperature
18–24 °C
Plant spacing
45 cm
Row spacing
45 cm
Sowing depth
0.5 cm
Height
120 cm
Spread
60 cm
Calendar
JJan
FFeb
MMar
AApr
MMay
JJun
JJul
AAug
SSep
OOct
NNov
DDec
Sow Indoors
Sow Outdoors
Plant Out
Flowering / Harvest
Timings based on average frost dates in the UK. Sign up to set your frost dates.
Care tips
Start cosmos with warmth or sow once frost danger has passed, then plant into full sun and reasonably poor to moderate soil so plants do not grow too soft. Keep deadheading or cutting flowers, stake taller varieties early, and avoid overfeeding if you want better bloom than leaf.
Common pests
Slugs on young plants, aphids, powdery mildew late in the season.
Companions
No companion crops have been added yet.
Don’t grow with
No crops to avoid have been added yet.