Cosmos Seeds

Growing cosmos seeds

There really is a cosmos for every type of garden. ‘Brightness Mixed’ has orange, yellow and scarlet flowers, while ‘White Knight’ has snowy double blooms. Plants range from around 30cm in height to 90cm depending on the variety, making them suitable for both the front and back of borders. Single flowers are particularly good for pollinators.

When to grow cosmos seeds

Cosmos are half hardy annuals so should be started under cover from March to April to flower from July. Plant out after the last frost. They can also be sown directly into the ground from March to May for flowering in late summer.

How to grow cosmos seeds

Sow your cosmos seed in a seed tray of damp multi-purpose or seed compost. Cover with about 3mm of compost. Put in a heated propagator or cover with a plastic bag and put it somewhere warm. Prick out the seedlings into small pots when they have two pairs of leaves and grow them under cover.

Plant out after the last frost into a sunny site that drains well but does not dry out. Keep deadheading to encourage more flowers.