Cosmos Choosing and growing cosmos From Garden Answers magazine Cosmos are the rising stars of the annual border and are never reduced to the currant buns we so often see in the case of French marigolds. They're tall and so invaluable in mixed borders amongst perennials, backed by shrubs and in annual plantings where their height, their elegance and their long and prolific flowering season are all crucial to the best of summer gardens. And, if you still need convincing, the seeds are large and easy to sow and the plants are easy to raise. For decades the mixed 'Sensation' at 4ft (1.2m) was about the only variety available - now the range has expanded enormously. Single colours of this type have also been available for some time - if you knew where to find them. The clean white 'Purity' looks spectacular against the background of a purple-leaved shrub like Cotinus coggygria 'Nottcutts Variety'. 'Versailles Tetra', in rich slaty red, makes a sultry combination against the same background or the silver of Hippophae rhamnoides. 'Sonata' was the first of a shorter type at about 18in (45cm) and this is a superb series, the white in particular is sometimes available separately and is gorgeous with silver Helichrysum petiolare straining through it or behind Artemisia 'Powis Castle'. Growing from seed Sow outside where the plants are to flower in May, although sowing indoors in March or April and moving the plants on to 5in (12.5cm) pots brings them into flower sooner. Grown in this way the plants will usually starting to flower at planting time at the end of May so separate colours can be picked out for the right planting places.   Buying cosmos Flowering plants of 'Sonata' are often available in large pots in garden centres in May and June. Thompson & Morgan has the best range of varieties with five mixtures and ten separate colours. Best mixture The tall 'Sea Shells' has the petals rolled into tubes creating a delightful and interesting effect. 'Sonata' is the best dwarf type. 'Gazebo' is in between in height. Best single colour The white 'Purity' is outstanding, 'Pied Piper Red' is the first separate colour in the 'Sea Shells' type, 'Picotee', with white petals edged in red, is very dramatic. Best for the future New doubles are on the way. Don't forget All these I've mentioned are forms of Cosmos bipinnatus, with feathery foliage and flowers in reds, pinks and white. The forms of C. sulphureus are smaller and come in yellow, orange or red; in warm, sunny gardens they are superb - but they do need the heat. Seeds sources 'Gazebo' - T&M 'Picotee' - B, CS, PoD, T&M, 'Pied Piper Red' - M, T&M 'Psyche' - CS, T&M 'Purity' - T&M 'Seas Shells' - B, CS, D, M, MF, PoD, S, T&M 'Sensation' - B, CS, D, M, MF, S, T&M, U 'Sonata Mixed'- B, D, M, MF, S, T&M, U 'Sonata White' - D, M (also pink, blush, and carmine), PoD (also pink and carmine), T&M 'Versailles Tetra' - T&M Cosmos sulphureus varieties - T&M   First published in Garden Answers magazine, April 1999 Cosmos A-Z ©copyright 1999 Graham Rice. All Rights Reserved. All Images Digitally Watermarked.