How to Grow Cosmos

There are more than 20 varieties of Cosmos – some of which are annuals and some perennials. They display modest leaves that split into elegant and colourful daisy-like flowers. The lush green ferny foliage compliments these blousy blooms beautifully throughout summer into early autumn. They make fantastic cut flowers and look good in borders and beds within cottage and informal gardens. Cosmos can grow to an approximate height of 90cm (36”) and a spread of between 30-40cm (12-16”).

Cosmos are best planted in moist well-drained soil of loam, sand, chalk or clay within an acidic, alkaline or neutral PH balance. Hot and dry weather are optimum conditions for growing Cosmos as they thrive in a position of full sun. There is no need to add any extra feed or fertiliser to these plants at the time of planting as they will grow healthily in poorer soil conditions.

Cosmos are relatively low maintenance plants. You may wish to deadhead spent flower heads to encourage further growth. Cosmos may require staking if they are planted in an exposed site or during adverse weather conditions to maintain a healthy structure and shape. Water your plants regularly, ensuring not to over water as this could reduce the amount and quality of flowers that are produced.

It is possible to propagate Cosmos by seed during late spring.