Tender and Tropical You can use these plants to fill gaps after you have cut down earlier flowering perennials such as poppies. Gorgeous Salvia guarantica reaches 1.8m (6ft) and carries bright blue flowers. S. involucrata is sugar-pink and has a tropical feel. If you live in a cooler area then take cuttings of your salvias in late summer and grow them on under cover ready for spring.
Some sages are late-summer performers. Silver leaved Salvia farinacea, sky-blue S. uliginosa, soft pink S. puberula and S. involucrata will all provide colour in autumn. Many of the more tender perennial sages are tall, providing height and colour at the back of the late summer border.
For a tropical look, cannas are still going strong into autumn. Lush flowers in a range of colours, and bold foliage make them an arresting autumn plant. New cultivars with colourful striped foliage bring added drama to the garden. Cannas need a warm, frost-free position unless you protect the roots in winter. They are heavy feeders and need plenty of water. Deadhead regularly to promote long-flowering and cut back to the roots after flowering.
Another colourful plant with a tropical air is Alstroemeria or Peruvian lily. Alstroemerias are long flowering and come in a range of shades from pale lemon through pinks and red into greenish shades. There are some lovely new, compact cultivars such as 'Zavina' as well as some older favourites such as 'Walter Fleming' and 'Mona Lisa'. Plant in full sun in a good, well-fertilised and free draining soil, deadhead regularly, and they will soon form substantial clumps and flower from spring to summer. In colder areas protect the roots with frost cloth, bracken or move to a frost-free position in winter.
Annuals Annuals can be sued to fill gaps left by collapsing poppies and lupins, or simply to add a little zap to a flagging planting scheme. Plants as easy and common as Tagetes, the ordinary French marigold, will flower well into autumn, providing a splash of clear yellow in the front of the border.
Annual salvias are indispensable late summer flowering plants. Seen in almost any bedding scheme, the annual Salvia splendens comes in a bold red and can be used to liven up a drooping planting scheme come late summer. Salvia farinacaea is another annual salvia with tall deep blue flower spikes, growing to 60cm (2ft).
Cosmos bipinnatus is a late flowering annual that will reach 1.5m (5ft) and carries masses of pink through magenta flowers. A recent introduction is a form of C. atrosanguineus, the chocolate cosmos. Cleomes will also provide a haze of pink at 1.2m (4ft) the flowers have an unusual spidery form.
Outshine Autumn So indulge in a late summer surge of creativity and put a hold on the clean up this year. Get busy with a mid-summer cutback instead, deadhead regularly and introduce plants with bold colour and drama into your borders.
Watch summer go out with an explosion of real flower power, and outshine the autumn foliage display.
Most perennials benefit from autumn planting, when they can develop a good root system before winter cold sets in and stops growth. Planting now requires means that you will have to keep new plants well watered.
Dig in plenty of organic compost, add some grit of fine gravel to the bottom of the planting hole if your soil is clay-like or heavy, and avoid nitrogen rich fertilisers as these will promote lush growth that will be vulnerable to early frosts.
For more impact and a more cohesive scheme, plant in groups of three or five, even in a smaller garden, rather than choosing one of everything at the nursery.
