Looking out of my kitchen window I see a cloud of dainty white flowers – Cosmos bipinnatus ‘Purity’.  They have flowered brilliantly all summer and now, when many other plants are starting to fade, they resolutely ignore the coming cold and continue their magnificent display. The evening primroses are turning their attentions to seeds rather than flowers, the witch hazel is changing to its autumn colours and the roses and hollyhocks are beginning to fade but the cosmos are behaving as it if is still high summer. The same applies at Fulham Palace, where I go most days to write. Their flower beds are filled with cosmos from pure white to crimson, with every variation in between.

I have a lot of cosmos in my garden, mainly because, each year, I am tempted to try different cultivars but resolutely refuse to give up my stalwarts of previous years. For a few years the permanents have been ‘Purity’, ‘Versailles Red’ and ‘Candy Stripe’. Last year I tried ‘Xanthos’ and this has now joined the ranks of the permanents.

‘Purity’ is beautiful but it is really a bit too tall for my garden where, because of the size, everything is viewed close-up. The flowers are beautiful and the plants airy and graceful but most of the flowers are on wafty stems over 6ft up – and I’m not that tall. I don’t usually like double flowers but this year I’ve grown ‘Psyche White’ which is a semi-double with prettily-edged, pure white petals which look like an eighteenth-century gentleman’s ruff. It grows to a more manageable height of about 3ft, and, although it doesn’t have as many flowers as some of my other cultivars, I think that may be because it was sat on by a neighbouring thug when young (an over-enthusiastic cucumber).

‘Candy Stripe’ is one of the many varieties of pink-and-white or red-and-white cosmos. On a single plant the flowers vary from pink with white highlights to white with the merest hint of pink at the edge of each petal. The snag for me is that, like ‘Purity’, it’s very tall. ‘Velouette’ is shorter and has deeper carmine markings and, with a RHS AGM, might be a good alternative. 

‘Xanthos’ grows into a bushy, flower-covered plant reaching about 2-3ft and has exquisitely-shaped pale yellow flowers with white centres. The buds are tiny, so tiny that at first I thought they’d never grow into flowers. I snip each flower off just above the next bud and, in a few days, am rewarded with new flowers.  The RHS magazine in August recommended ‘Lemonade’ which is 2ft tall and has similar-coloured flowers but in a simpler single form. Another one to try.

‘Versailles Red’ reaches 3ft and has rich deep red flowers but this year I also grew ‘Rubenza’ which is taller, at 4ft, and has dark pinky-red flowers. The ‘Versailles Red’ petals seem slightly more velvety but that appearance may just be down to the fact that they are in the prime position in my garden; a container by the kitchen door that is in full sun and which I always remember to water. Rather than producing different coloured flowers ‘Antiquity’ has blooms that change colour as they age. The buds open to a deep rich crimson and then fade to a delicate pink, rather like velvet that has been hanging in a sunny window for many years. At only 2ft it is one of the few cosmos that doesn’t need staking. ‘Rubenza’ is another cultivar that fades with age, whilst the ruffled petals of ‘Apollo Carmine’ seem to remain a fabulous deep magenta. I either need a bigger garden or to grow nothing but cosmos next year.

Jane