This week...Cosmos

Cosmos come in a range of colours and sizes to suit every type of garden

- GRAHAM RICE

COSMOS, sometimes called cosmea or Mexican aster, is a sun-loving plant with saucer-shaped flowers like daisies. Most grow wild in Mexico. They are very colourful, easy-to-grow plants that are usually grown from seed sown each spring (annuals) and pulled out in the autumn.

Some cosmos varieties bloom happily at knee-height, flowering on short plants about 12-15in (30-38cm) tall, while others can reach head-height, 5-6ft (1.5-1.8m), with different varieties at all heights in between.

All cosmos have flowers with the same general appearance. In the centre of each flower are rings of tiny individual flowers (florets) that together form an eye or disc. Starting from the outside of the disc, each ring of tiny florets opens one after the other to shed pollen for the bees to collect. Usually these florets are yellow, orange or gold but they can also be reddish.

Surrounding the disc are the petals (rays). These are large and brightly coloured in a range of tones and serve to attract pollinators to the flowers. The leaves are usually fine and feathery, but can be flat and narrow. Cosmos have large, easy-to-handle seeds that sprout soon after sowing and grow strongly.

How to care for cosmos

When your outdoor-sown seeds come up and start to develop leaves, check the final spacings recommended on the seed packet.

Snip off some of the seedlings at soil level with kitchen scissors, leave them at half the spacing suggested on the packet. Two or three weeks later snip off some more to leave the plants at their final spacing.

At this stage, if there are gaps, transplant seedlings into the spaces instead of snipping them off. Irrigate in dry spells, support taller varieties with canes and string, put down more slug bait if necessary.

Snip off the flowers as they fade to encourage more flower buds to develop and flowering should continue until the first frosts.