10 award-winning (AGM) grasses for your autumn garden

Grasses make a wonderful contribution to gardens, providing airy structure and forming delightful contrasts with other plants. Many come to the fore in autumn as their long-lasting flowerheads reach their peak. Here are 10 of the best, all winners of the RHS Award of Garden Merit – which means they are straightforward to grow and widely available to buy.

Golden oats

A robust, tufted evergreen grass, with linear green leaves

Stipa gigantea is a fine specimen grass but also one of the most valuable see-through plants – it makes its presence felt without blocking the view through to plants behind it. Greyish leaves make impressive evergreen clumps, topped through summer with oat-like flowers that catch the light and shiver in the wind, ripening to pale yellow in autumn. Best in sun, dislikes wet winter soil. 2m (6ft 6in). Hardiness rating H4.

Fountain grass

Arching stems bear bottlebrush-shaped flowers in late summer to autumn

Pennisetum × advena ‘Rubrum’ is a frost-tender grass with deep red foliage from planting time in May right through the summer and into autumn. In September and October arching heads of reddish flowers add to the display. Superb in containers with calibrachoas or helichrysum and can be overwintered in a conservatory. 1m (3ft 3in). Hardiness rating H3.

Purple moor grass

An herbaceous grass forming a compact clump of arching leaves

Molinia caerulea subsp. caerulea ‘Variegata’ – this

Variegated means having leaves or other plant parts with streaks, blotches or patches of different colours. Typically, these would be a combination of two colours, such as green and gold or green and white.

The acidity/alkalinity of soil is measured on a pH scale, which runs from 0 to 14. Neutral soil has a pH of 7. Acid (or ericaceous) soil has a pH of less than 7, and the lower the pH, the more acidic the soil. You can measure your soil pH using a simple testing kit. Acid-loving (ericaceous) plants include rhododendrons, camellias, heathers and blueberries. Adding lime to soil will reduce its acidity. A slightly acidic soil of pH 6.5 is the best general-purpose pH for gardens, allowing a wide range of plants to grow.

acid soil

Miscanthus ‘Kleine Silberspinne’

Its white midribs, and feathery reddish flower grows to 1.2m tall in late summer

A short miscanthus, the dark green leaves of Miscanthus sinensis ‘Kleine Silberspinne’ turn deep reddish orange and gold, then the mature to straw colour. The rosy pink flowers open in August on unusually bright green, upright stems, then become brown and fluffy as they mature. The whole plant still looks good in winter. Height 1.2m (3ft 11in). Hardiness rating H6.

Miscanthus ‘Ferner Osten’

This plant has narrow leaves which turn dull orange in autumn and early winter

Miscanthus come in a range of foliage and flower colours. The narrow, olive-tinted foliage of Miscanthus sinensis ‘Ferner Osten’ has a slim cream midrib and turns bright orange in autumn. The rich red, white tipped flowerheads open in August, then mature through autumn, turning silver and beige. Flowers best in full sun. 1.6m (5ft 3in). Hardiness rating H6.

Golden Japanese forest grass

An elegant deciduous grass with insignificant pale green flowers in late summer

Hakonechloa macra ‘Alboaurea’ is a neat but supremely elegant grass featuring a very appealing fountain of yellow-striped foliage for many months. Then in autumn reddish tints appear before the whole plant turns biscuit brown, and the leaves are retained into the winter. A fine specimen for containers, and also in good soil in sun or partial shade. 35cm (13in). Hardiness rating H7.

Silver Feather pampas grass

A small, compact cultivar suitable for small gardens

Cortaderia selloana Silver Feather (‘Notcort’) is a pampas grass in a very different style, making a more manageable plant and with each of the leaves striped in silver creating the look of a silvery grey clump. The plumes are noticeably upright, on short stems and open in September, peaking in October. So while its floral impact is at its most impressive in autumn, there is the bonus of all-year variegated foliage. 1.8m (5ft 10in). Hardiness rating H6.

Toetoe, the Kiwi pampas

This species origins from wet habitats in New Zealand

There is unexpected variety in pampas grasses, and Cortaderia fulvida (Buchanan) Zotov from New Zealand is a large and long-flowering species for use as a dramatic specimen. Opening in gold tones in July, as the months pass the arching, one-sided plumes change from pink and creamy white to beige and, unlike those of many other types, the plumes do not fall apart in winter but retain their shape and tawny colour almost till spring. 2.5m (8ft 2in). Hardiness rating H5.

Foxtail grass

This plant forms a clump of glossy green, linear leaves turning yellow in autumn

Calamagrostis brachytricha makes dense clumps of glossy green leaves, with pink-tinted, silvery grey flowerheads in summer and early autumn. These turn biscuit-brown and last well into winter. In autumn the whole clump of arching leaves turns yellow. Best in sun and good soil, cut the whole plant back to 15cm in spring. 1m (3ft 3in) or more. Hardiness rating H6.

Pheasant-tail grass

An elegant clump-forming grass with narrow leaves

Sometimes known under its former name of Stipa arundinacea, Anemanthele lessoniana is a lovely clump-forming grass from New Zealand. It features relatively broad green foliage all summer – which in autumn takes on orange, red and yellow tints before toning itself down into warm autumnal browns. Best in rich soil that is well drained, preferably in sun. Lovely airy flowerheads open in late summer. 50cm (19in). Hardiness rating H4.