My delphiniums and lupins are long gone, my roses are fading and the giant-flowered hybrid clematis are past their best, but my perennial borders remain a riot of colour thanks to a few, well-chosen gems.
Late summer can be a time when colour is at its hottest, when blazing crocosmia, burnt orange helenium, bright yellow rudbeckias, acid green euphorbias and other plants come into their own.
Exotic orange ginger lilies (Hedychium), which release a great scent, clash with vibrant red Dahlia ‘Bishop of Llandaff’ or its relative D. ‘Tally Ho’, with its hot, deep orange flowers.
If you prefer pastel shades, plant sun-loving cone flowers (Echinacea) in shades of pink and white.
The daisy-like flowers and height (they can grow to 150cm (5ft) tall) mean they work well towards the back of the border, attracting bees and butterflies and adding impact alongside globe thistle (Echinops) and monarda.
Some varieties have rich colours that can be combined with fuchsias, or blue salvias. E. ‘White Swan’, a white variety with yellow centre, provides a cooling companion dotted within the hot border.
If you thought hard before summer started and were wise enough to plant some nasturtium seeds in your hanging baskets and patio pots, they should be now showing their true colours.
Clumps of bulbs are particularly useful in extending the season. Spikes of crocosmia will add architectural interest to the late summer border, their upright, spiky leaves with elegant sprays of orange-red flowers brightening the scene.
My favourite is C. ‘Lucifer’, a variety growing to 120cm (4ft), which produces brilliant red flowers and looks wonderful grown alongside the purple-leaved smoke bush, Cotinus ‘Royal Purple’, or against a backdrop of acid-green evergreens.
Many warm yellow herbaceous perennials look fantastic in mass plantings, such as the long-lasting Rudbeckia fulgida ‘Goldsturm’ and late season heliopsis.
Bronze or burgundy leaves look fantastic mixed with the hot-coloured border. Place shrubs with red-purple foliage, such as Berberis thunbergii f. atropurpurea, behind red or orange plants.
The burgundy leaves of heucheras also make a wonderful foil at the front of the border.
Other good choices include the herbaceous perennial Lysimachia ciliata ‘Firecracker’, a moisture-loving bronze-leaved plant with brilliant yellow flowers.
Use drifts of perennial border phloxes in the middle of borders to provide intense pools of summer colour. Herbaceous potentillas or small asters can be planted in front to hide the bare phlox stems.
Phloxes are ideal follow-on plants for poppies and shouldn’t need staking except in windy gardens. Don’t let them dry out in summer as they need a moist soil.
Hotter subjects include red hot pokers (kniphofia), which produce rocket-shaped flowers, some red with yellow at the base, others a single colour, and the red tradescantia, T. ‘Carmine Glow’, a low-growing perennial (usually growing to around 60cm so perfect for the front of the border) with strap-like foliage which flowers until September.
Red varieties of astilbe such as ‘Feuer’ will give you coral-red flowers to September, above delicate feathery plumes.
They thrive in moist ground in partial shade and can really brighten up a woodland scene.
If you want to add late summer-flowering plants to an existing border, buy as many of the same colour and variety as you can afford and repeat-plant them through the border to develop a sense of rhythm.
When mixing colours try to avoid using too many pastels with hot colours as the brighter hues will swamp the more subtle ones.
If you plan carefully, your sizzling summer colour can last right through to autumn.
JOBS FOR THE WEEK:
lApply a high-potash liquid feed to dahlias, water regularly and tie in new growth to the stakes.
lPrune espalier and cordon-grown apple and pear trees.
lPlant summer varieties of strawberries to crop next year.
lStart off the first spring cabbages.
lRemove the growing tips of tomato plants in the greenhouse to encourage rapid development of top trusses.
lHand weed heather beds and replace mulch if necessary.
lHarvest and freeze gluts of crops including French and runner beans.
lPlant madonna lilies (Lilium candidum) in a warm, sunny spot in well-drained soil, covering the bulbs with no more than 5cm (2in) of soil. They should start into growth next month.
lCollect seeds from hardy annuals, harvesting them on a dry sunny day and popping them into paper bags. Store them in labelled paper envelopes in a cool, dry place.
lCut back wayward perennials which have spread over the lawn.
lTrim faded flower spikes from lavender.
lMow the lawn regularly, raising the blades if the weather is very hot and dry.