It may be the start of a new season, but September is set to stun with sensational colours within the county’s best hot borders. Find out what will work in your own garden, and how to replicate this late-summer look.

September is one of my favourite times in the garden with glorious bursts of colour before the mellow tones of autumn and the gentle fading in the borders takes on a resting beauty of their own.

Three flowers in particular come to the fore in late summer until the first frosts – dazzling dahlias, the starry-shaped Michaelmas daisies and textural spires of salvias. Combined with other late season annual and perennial flowers such as repeat-flowering roses and shimmering ornamental grasses, the September border has the mesmerising nature of an impressionist painting, especially when enlivened by the slightest breeze. Two National Garden Scheme gardens to enjoy for their inspiring borders as summer begins to give way to autumn are Redenham Park House near Andover and Wheatley House in Kingsley.

Great British Life: Orange and blue is a striking combination at Wheatley HouseOrange and blue is a striking combination at Wheatley House

At Redenham Park House, home to garden designer Lady Olivia Clark, you will find an elegant garden that has evolved over time, with garden rooms of themed spaces spreading out from behind the 1784 handsome house.

From the tranquillity of the formal rose garden, you step through to the main herbaceous borders, at their zenith in late summer with a fiery blaze of hot colours. Backed by a neatly clipped foil of deep green yew hedging, orange and red dahlias, including the ever-popular ‘Bishop of Llandaff’, stand tall, accompanied by daisy-like tithonias, striped cannas and feathery plumes of Macleaya cordata. Edging the deep herbaceous beds are low plantings of sedums and nepeta.

Architectural structure is provided by an oak pavilion at the centre of the two borders, along with clipped box topiary and cardoons. As you wander along the border take time to see how the colours merge from reds, orange and yellow to the bright pinks of further dahlias, Michaelmas daisies and splashes of cooling whites. Further exploration of the garden ‘rooms’ takes you through an avenue of pleached limes, an area with a cottage style medley of harmonious blues and mauves from Michaelmas daisies, fennel, and lavender, cleverly framed by espaliered pears and punctuated with basil spilling out of urns, a delightful, thatched summerhouse by the pool and finally to the productive area through a door in the cob wall. Here vegetables, trained fruit, fragrant herbs and cut flowers fill the beds, including masses of dahlias for the vase.

Great British Life: Lady Clark in the cutting gardenLady Clark in the cutting garden

‘I love being in the kitchen garden each day and in September the beds of dahlias are a highlight,’ Lady Clark adds.

The use of colour is also inspirational at Wheatley House, a large country garden set on a sloping site. Here Susannah Adlington ‘paints’ her garden with glorious combinations in sweeping colour-coordinated borders, selecting plants for their visual appeal of both flower and foliage.

Peaking in late summer to autumn, the hues intensify in a crescendo of warm tones in the main border. ‘It works like a colour wheel, fluctuating from pinks and purples, through oranges, blues, yellows and then back to pink,’ Susannah explains.

Another border uses rich lilac and scarlet, and black, red and white features in a bed that always attracts comments from the visitors. Look out for the newest colour-theming with coral and deep blue. Again, you will find the striking Dahlia ‘Bishop of Llandaff’, but also many others, such as large cactus forms in clear pink making a statement in a swathe, accompanied by hot pink salvia spires. ‘Being on top of a hill and therefore not in a frost pocket I only lift the dahlias if they need dividing,’ she adds. I also enjoyed the use of colour contrasts, such as sky-blue salvias against low-growing open-faced orange dahlias and clumps of mauve Michaelmas daisies.

Great British Life: Salvia nemerosa 'Caradonna' is a popular choiceSalvia nemerosa 'Caradonna' is a popular choice (Image: Leigh Clapp)

‘I have a love/hate relationship with Michaelmas daisies as they have a habit of spreading like wildfire in our rich soil, which is upper greensand, neutral, so I’m constantly pulling them out, but they do provide wonderful autumn colour,’ she smiles.

Visual punctuation with sculptural pieces adds further interest amongst the dense medley and at the open day pieces are for sale, along with plants from the garden.

Pay a visit

Redenham Park House, Andover, SP11 9AQ

Open September 22, 2-5pm

Admission £6, child £2.50

Home-made teas and cream teas in the thatched pool house

Wheatley house, Bordon, GU35 9PA

Open October 1, 2-5pm

Admission £5

Get the look

• Plan your colour progression and merge tones.

• Hot colours bring energy and warmth, harmonious tones are soothing.

• Use foliage as a foil and to link colour.

• Red dahlias work affectively with the warmth of orange, purple and a hint of cool lime or blue.

• Deep tones stand up to bright light.

• Open dahlias, Michaelmas daisies and salvias are also great for bees.