10 award-winning (AGM) late-flowering perennials

As days begin to shorten, we start to think of berries and autumn foliage colour – but this is also the season when an unexpectedly wide range of autumn-flowering hardy perennials start to come into their own.

Michaelmas daisies, now classed botanically as Symphyotrichum, are perhaps the first to come to mind, in their vast array of flower colours and flower forms and heights. Penstemons, too, can be kept flowering into November with regular deadheading.

But there are many other easy-to-grow

Perennials are any plant living for at least three years. The term is also commonly used for herbaceous perennials which grow for many years (To compare: annual = one year, biennial = two years).

Fragrance and flowers

Dense spikes of small, violet-blue flowers appear from summer to early autumn

Agastache ‘Blue Fortune’ is attractive to butterflies

Since agastaches began to come to the fore, we’ve started to depend on their aromatic foliage, their long season of flowers, and their appeal to butterflies. Agastache ‘Blue Fortune’ is one of the finest, with peppermint-scented foliage and upright spikes of violet-blue flowers opening in tiers from darker bracts. This is a plant that demands good drainage and sunshine – as part of a Mediterranean scheme it’s ideal and it will flower until October and never self sow. 1m. Hardiness rating H6.

Classic Japanese anemone

This plant is a clump-forming deciduous to semi-evergreen perennial

The swaying white flowers of Anemone × hybrida ‘Honorine Jobert’ start to enliven our borders in August and those golden-centred slightly frilly saucers keep coming into October. Plant them in sun or partial shade: ideally with brooding shade behind them to highlight those gleaming blooms. Just one thing: allow ‘Honorine Jobert’ room to spread as the woody roots tend to extend – and if you move your plant, prepare for new shoots to arise at the old site. 1.2m. Hardiness rating H7.

The perfect perennial?

Aster × frikartii ‘Mönch’ bears loose clusters of long-lasting daisies

Aster × frikartii ‘Mönch’ is one of the finest of all sun-loving perennials: neat and well branched but elegant, prolific, long-flowering and with soft lavender-blue petals surrounding a yellow eye. Lovely with grasses, sedums and schizostylis, it’s also good for cutting. It's also resistant to mildew and the flower colour varies slightly in different growing conditions. 90cm. Hardiness rating H7.

From Japan in a matchbox

The small, mauve-pink, pompon flowers appear in early to mid autumn

Chrysanthemums are always associated with autumn and even hardy types come in a vast variety of colours and forms. Chrysanthemum ‘Mei-kyo’ is one of the prettiest and most manageable. Making a neat, twiggy plant with unusually small foliage, for a couple of autumn months it produces small, button-like pompom flowers in pale purplish pink. The original

A method of growing new plants from parts of an existing plant, such as sections of root, stem, leaf or bud. When prepared correctly and planted in the right conditions, they can produce roots and eventually become independent plants. There is a wide range of different methods for taking cuttings, depending on the plant and time of year.

Red and blue combo

This is a low-growing, mat-forming herbaceous perennial with spreading roots

The bushy, slightly twiggy growth of the hardy plumbago, Ceratostigma plumbaginoides, brings us a rare combination of foliage and flower colours. The clusters of sharp blue flowers, a little like those of a periwinkle, open in September and October on wiry reddish stems, but the special feature of this indispensible plant is that the leaves start to turn scarlet as the flowers are at their peak. An essential front-of-the-border plant for sun. 45cm. Hardiness rating H5.

South American sea holly

An imposing plant, forming a dense clump of large, sword-shaped, spiny-margined leaves

Eryngium pandanifolium is a monster relative of our native sea holly we find on gravel beaches, and whose habitat reminds us that good drainage is valued by this more imposing relation. First making a bold clump of narrow, softly spiny, slightly bluish leaves, from the centre erupt tall, repeatedly branching upright stems carrying small, tight, egg-shaped reddish-purple flower heads. 2.5m. Hardiness rating H4.

Flowering ginger

Hedychium ‘Tara’ is an erect herbaceous perennial with fragrant orange flowers

We usually think of buying ginger in the supermarket rather than growing it in the garden, but this autumn-flowering ornamental ginger is so good it has received an AGM. Hedychium ‘Tara’ is an imposing plant with slightly leathery lance-shaped foliage and impressive heads of fragrant reddish-orange flowers. Best with good drainage and high fertility, it needs protection over winter in cooler areas. Good for dramatic effect. 2m. Hardiness rating H4.

New slant on old favourite

Hylotelephium ‘Red Cauli’ with flattish heads of small, starry pink flowers in late summer and early autumn

Hylotelephium is the new moniker for the hardy

Perennials are plants that live for multiple years. They come in all shapes and sizes and fill our gardens with colourful flowers and ornamental foliage. Many are hardy and can survive outdoors all year round, while less hardy types need protection over winter. The term herbaceous perennial is used to describe long-lived plants without a permanent woody structure (they die back to ground level each autumn), distinguishing them from trees, shrubs and sub-shrubs.

Long season lifeline

Salvia ‘Amistad’ looks lovely in a vase with a pink Rosa ‘Mary Rose’

Salvia ‘Amistad’ is a plant that will grace your border from May until October, especially if deadheaded, so it does the job of two or three other plants. The shimmering purple flowers stand out to face the light from the near-black calyces, all held on long, slender, elegant and equally dark stems. 1.2m. Hardiness rating H3 (needs winter protection in cold areas).

Trials triumph

A Wisley trial of hardy autumn-flowering perennial saxifrages revealed the value of these neat little perennials

Saxifraga ‘Shiranami’ has double, clear white, starry flowers held over glossy, fresh green foliage for many weeks in autumn. Best planted in partial shade in that elusive combination of humus-rich but well drained soil. 25cm. Hardiness rating H4.