Cosmos (Cosmos bipinnatus) - Half-Hardy Annual
Cosmos are natives of Mexico and are a must-have for me in the cutting garden as they are easy to grow, flower prolifically and bees and hoverflies love them.
When to sow: Indoors in mid-Spring or outdoors in late Spring
When to plant out: After the last frosts - I leave mine until the end of May
Flowering time: Mid-Summer until the first frosts
Pinch out?: Yes, when 15 cm / 6" tall
Conditions: Full Sun
Height: 45 cm-1.5 m / 18"-5ft, depending on the variety
Support?: Yes, for the taller varieties
When to pick: As the petals start to unfurl
Recommended varieties: I like 'Purity' (pure white), the dark pink 'Rubenza' and bright pink 'Dazzler' and, for its ruffled flower shape, 'Click Cranberries'
Vase life: 7-10 days
Conditioning: Leave for several hours or overnight in a deep bucket of water
Good for: Providing many flowers from one plant. They look great arranged on their own or part of a larger arrangement