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Cosmos bipinnatus 'Velouette'

The best cosmos to grow

Colourful cosmos is as brilliant in the garden as in the vase. Here, plant expert Graham Rice chooses his favourite cosmos. Photos by Jason Ingram

New and recent introductions make colourful cosmos as brilliant in the garden as it is in the vase. Annuals are often looked down upon by some gardeners as not in the same league as perennials but annual summer displays, like the one of almost 90 cosmos at RHS Garden Wisley, makes it clear what valuable plants they are.
As a mini-introduction, Cosmos bipinnatus is a vigorous annual reaching from 60cm to 3m or more, with stout upright stems carrying large, attractive, fresh-green foliage repeatedly divided into thread-like segments. From mid-summer into autumn, large golden-centred daisies open in a wide range of pink and red-rich shades with white.
Here, plant expert Graham Rice runs through a selection of cosmos that he thinks are well-worth growing.

Cosmos bipinnatus ‘Antiquity’

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Cosmos Plant Profile at RHS Wisley (23rd August 2016)

A shorter newcomer cosmos whose single flowers fade from rich red to paler ‘antique’ tones and finally  to a rather watery shade. Deadhead when the flowers begin to look ragged.

Height 60cm.

Cosmos sulphureus ‘Carioca’

Cosmos Plant Profile at RHS Wisley (23rd August 2016)

Wonderful, glowing-orange single cosmos flowers on plants with appealingly open growth, slow to start but prolific later. Lovely interplanted among dark-leaved cannas or dahlias for contrast in habit and colour.

Height 1m.

Cosmos bipinnatus ‘Double Click Rose Bonbon’

Cosmos Plant Profile at RHS Wisley (23rd August 2016)

Double-flowered cosmos forms can be disappointing. This is the pick from Wisley because although there were very few doubles, the singles and fluted flowers matched perfectly in colour to create a fascinating, rosy-pink blend.

Height 1.8m.

Buy Cosmos Bipinnatus ‘Double Click Rose Bonbon’ from Thompson & Morgan

Cosmos bipinnatus ‘Candy Stripe’

Cosmos Plant Profile at RHS Wisley (23rd August 2016)

Tall, rather leafy cosmos plants with fresh-green foliage carry single, long-stemmed white flowers, each vividly edged with bright carmine. Some flowers are almost fully white, the variability in the markings adds to the appeal.

Height 2m.

Cosmos bipinnatus ‘Cupcakes White’

Cosmos Plant Profile at RHS Wisley (23rd August 2016)

These cosmos have cupped flowers with white petals fused into huge bowls, but with some pink-tinted and split flowers. Alternatively, ‘Cupcakes Mixed’ has a balance of white and pink shades. Voted People’s Favourite by Wisley visitors.

Height 1.2m.

Cosmos bipinnatus ‘Rubenza’

Cosmos Plant Profile at RHS Wisley (23rd August 2016)

Deep-red, scarlet or deep-pink single cosmos flowers on tall but prolific plants. Rich colouring and  good with silver foliage, the flowers age harmoniously but eventually need regular deadheading.

Height 1.5m. Hardiness RHS H3.

Cosmos bipinnatus ‘Xanthos’

Cosmos Plant Profile at RHS Wisley (23rd August 2016)

Very pretty cosmos that is a Fleuroselect Gold Medal winner. The small, mostly single, primrose-yellow flowers have a neat, white ring around the golden eye; a few flowers have extra petals and there are a few white flowers.

Height 1m.

Cosmos bipinnatus ‘Cosimo Red-White’

Cosmos Plant Profile at RHS Wisley (23rd August 2016)

Like a shorter version of ‘Candy Stripe’, the striking plants are best early and mid-season, while the compact foliage allows the flowers to bloom unhidden. Cruder in colour than the softer, but taller, Cosmos ‘Capriola’.

Height 60cm.

Cosmos bipinnatus ‘Apollo Carmine’

Cosmos Plant Profile at RHS Wisley (23rd August 2016)

One of the best cosmos in the Wisley display, short plants carry rich, carmine single flowers that hold their colour well and fade harmoniously into pinkish tones. Good flower shape and size, ideal in large containers.

Height 60cm.

Find Cosmos Bipinnatus ‘Apollo Carmine’ through the RHS

Cosmos bipinnatus ‘Apollo Pink’

Cosmos Plant Profile at RHS Wisley (23rd August 2016)

Nicely rippled, rose-pink single cosmos flowers face upward from uniformly neat plants, the colour hardly fading before the petals start to drop. An improvement on the similar, but now unacceptably variable, ‘Sonata Pink’.

Height 60cm.

Buy Cosmos Bipinnatus ‘Apollo Pink’ from Hayloft

Cosmos bipinnatus ‘Apollo White’

Cosmos Plant Profile at RHS Wisley (23rd August 2016)

Large, flat, upward-facing, pure-white flowers on plants of uniform height, Cosmos ‘Apollo White’ flowers consistently from June until well into the autumn. The Apollo Series is the new standard in short cosmos.

Height 60cm.

Buy Cosmos Bipinnatus ‘Apollo White’ from Hayloft

Cosmos sulphureus ‘Brightness Red’

Cosmos Plant Profile at RHS Wisley (23rd August 2016)

Semi-double flowers in vivid reddish orange, with a few orange-flowered plants mixed in. Flowers are sparse at first but prolific later on, and open at various heights on the plant, not only at the top.

Height 50cm.

Find Cosmos Sulphureus ‘Brightness Red’ through the RHS

Cosmos bipinnatus ‘Capriola’

Cosmos Plant Profile at RHS Wisley (23rd August 2016)

My favourite, the white flowers are exquisite with their unique pattern: each petal on this cosmos is boldly tipped and edged in magenta pink with a similar ring around the eye. Sadly, it can be variable, and there are some ‘off’ types.

Height 1.2m.

Cosmos bipinnatus ‘Veloutte’

Cosmos bipinnatus 'Velouette'

Perhaps the most dramatic cultivar, white flowers are tipped and streaked in reddish carmine, though some flowers are almost entirely white and some completely carmine. Eventually this cosmos fades to parched pink, when deadheading is necessary.

Height 1m.

Buy Cosmos Bipinnatus ‘Veloutte’ from Dobies

Cosmos bipinnatus ‘Rosetta’

Cosmos bipinnatus 'Rosetta'

A new medium-height cultivar with large, mainly semi-double flowers striped in lavender pink and blushed white. Very pretty, early, long-flowering and prolific cosmos, but, strangely, its flowers all face in different directions.

Height 1.2m.

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Find Cosmos Bipinnatus ‘Rosetta’ through the RHS

Cosmos bipinnatus ‘Versailles Dark Rose’