Cosmos is a simple flower with large shallow saucer blooms in shades of pink, purple, deep red and white. The shades of colour are very varied, depending on variety.

The varieties offered by the seed houses are almost always of mixed colours, but there are some single-colour varieties sold too, such as the white kinds Purity and Psyche White. Also the red variety Rubenza and the really pretty Sweet Sixteen, which is white with a tiny, bright purple rim and a light suffusion of purple in the petals.

The pink-only variety Versailles Tetra has the brightest magenta pink flowers which are very eye-catching. These cosmos have single flowers, each with a ring of petals around a central yellow button. But there are double forms with puffy flowers, and some with petals rolled, such as Sea Shells. The magnificent flowers are shown off well against the background of dense, finely-divided foliage, unremarkable in itself but a great foil for the flowers.

All of these varieties are annuals that are easily grown from seeds. They are not frost-hardy however. They need to be sown in early to mid-spring each year. In early spring, the seeds are sown under glass in a greenhouse or conservatory. Later, in March or April, they are robust enough to be sown outdoors directly to flower from late summer. The earlier sowing will flower earlier in summer.

Very occasionally, in a mild winter or in a coastal garden, cosmos will self-sow, but they cannot be relied upon to do so. Cosmos is the Greek word for beautiful, and beautiful this flower certainly is. It can be used as a filler in a new garden where there is space to fill temporarily and keep weeds down. In older, established gardens, it can be used to give spots of exuberant growth and colour, to add a truly summery dimension to a garden.

As well as the purple, pink and white species, which is Cosmos bipinnatus, there is the very striking species called Cosmos sulphureus. Like the pink shades species, this flower is from Mexico, which explains its relative lack of hardiness, but it has a different range of colours, in this case, yellow, orange and red. Only in the red zone is there some overlap and even then, not really, because the shades of red are different, one leaning towards purple, the other towards orange.

The yellow group is not nearly as well-known as the pink one. The flowers of the yellow varieties are smaller, not as numerous and not as concentrated. While all that might seem negative, these are not fatal short-comings and the yellow cosmos can be a great addition to a hot-coloured border for summer flowering in a low-key way.

The Ladybird series is popular and can be bought in red-only or yellow-only. The yellow is sometimes offered as a mix with the pink sort, but this is not attractive, the colours mixed do not really work, partly because the yellow flower is not quite as saucer-shaped. Apart from the two annual species, there is the intriguing chocolate cosmos, (shown), so called because of its scent of warm chocolate from the flowers, and the deep chocolate-red colour of the flower petals. This is a perennial with tuberous roots, quite like dahlia, to which it is related.

The similarity of flowers and foliage is clear. This plant is not quite hardy and will need to be covered with compost in winter and watched closely for slug attack in late spring. But the scent is worth it.

Tomato time

Tomatoes from plants in a greenhouse are ripening now and ready for picking. The outdoor ones will be a little while yet, although they have made phenomenal growth this summer thanks to a long period of warm weather and rain too, especially lately.

Tomato plants grow like crazy if they get a chance, too much so, and they need to have unnecessary shoots, leaves and flower trusses removed. Small fruits that will never make it to ripeness should be removed to direct the plant’s resources into the larger developing fruit that the plant can add flavour to, and hopefully ripen. The outdoor kinds are always a bit of a gamble, but tomatoes grown outdoors are worth the effort because they have a firmness and concentrated flavour like no other.

Fruit, veg and herbs

Raspberry canes that have finished fruiting can be pruned out now and the new canes tied into position. If there are too many canes, reduce the number to about 10 or 15 per metre of row. Summer pruning of over-vigorous apples and pears could be carried out now to reduce vigour and increase cropping.

Trees, shrubs and roses

Summer prune roses by removing shoots with hips, cutting back to a good bud about halfway down the stem. This will improve late flowering. Check young trees and shrubs planted earlier this year or last year for signs of drought, and remove any competition from weeds or grass as these can badly affect young trees.

Lawn

Recent weeks have seen great growth of grass after a relatively dry month. High temperature levels keep the grass growing, along with occasional downpours. Lower the blades again if they were raised during the dry spell, as this will reduce stress on the grass. Keep lawn edges neat around beds and borders and along paths.

Flowers

Continue feeding baskets and other containers on a regular basis and keep up watering too. It is possible to collect seeds of perennial flowers, if it is desired to raise some new plants. Take cuttings of tender plants, such as marguerites, fuchsias and African daisies, to carry over winter before the end of the month.

Greenhouse and house plants

Re-pot houseplants as it is getting late in the season for such disruption. Continue watering and feeding greenhouse plants. Feeding should continue each week or two weeks, especially with flowering plants. Continue to train and side-shoot tomatoes, removing flowers and small fruit.