Why Miscanthus is the best tall grass for a winter garden

Ornamental grasses are the perfect way to add structure and beauty to your garden in winter. But with so many out there, which is best?

Miscanthus sinensis is the grass you’re after.

This will provide you with airy, plumed seed heads that endure from August until late January or longer. The plumes emerge in late summer or early autumn before fading to a silver-grey. The heads provide a translucent veil in winter sunlight as they disintegrate slowly.

The slightest breeze will add an extra dimension to the winter garden, as well as movement, so it’s important to position all miscanthus where they catch the light. Don’t tuck them away in deep shade.

M. sinensis has been grown in British gardens for more than a hundred years and the famous wild gardener William Robinson (1838-1935) grew it as Eulalia japonica, or the Chinese silver grass. Most of the 17 species come from Eastern Asia.

Gertrude Jekyll planted the horizontally banded 'Zebrinus', or Zebra Grass, to cast light and shade at Munstead Wood.

The range expanded dramatically when the German plant breeder Ernst Pagels persuaded one of his 'Gracillimus' plants to set seed under glass in the 1950s. His first batch of seedlings showed great variability and now there are plum-plumed varieties like 'Ferner Osten' as well as silver-plumed ones like 'Silberfeder'. Heights vary greatly and there are variegated forms.

Miscanthus flowering times vary

Miscanthus flowering times vary by as much as five weeks, depending where in Britain you live. RHS Wisley in Surrey (for instance) will sometimes have miscanthus in flower by July and Lady Farm Gardens in Somerset (a renowned NGS garden) will also have lots in flower by then.

However, in the heart of England, the earliest to flower is always 'Silberfeder' and even then it is always in the second half of August.

Those in even colder places, in Eastern Yorkshire for instance, may have to wait until September. For this reason the one miscanthus I always grow is 'Silberfeder' because it is reliably earlier than most.

Miscanthus planting and care

Wherever you live in Britain, miscanthus like good soil and summer rain - they get an abundance of the latter in Eastern Asia, which has a warm rainy season.

Newly-bought plants take at least three years to clump up to a decent size and many nurseries specialising in grasses recommend planting in threes and fives or "by the square metre" as Neil Lucas of Knoll Plants always advises.

Miscanthus are very hardy so they could be planted in the autumn, however late spring is the best time.

The Miscanthus to avoid

All varieties of M. sinensis form tight clumps and, although some varieties make large clumps, they all stay where you plant them. Do not be tempted to plant the evergreen Miscanthus transmorrisonensis, it will ramp through huge areas in all directions especially in hot, dry sites.

The best varieties of Miscanthus sinensis

There are 120 named varieties of M. sinensis currently available in Britain and more are being released yearly. Here is a selection of the best and most distinctive.

Variegated Miscanthus varieties

• Morning Light AGM - This slender miscanthus has vertically variegated fine leaves in pale-green and ivory. It has been grown in Japanese gardens since the 19th century and it’s very dainty reaching just 4ft in height (1.3m) - sometimes less. Although ‘Morning Light’ does flower after a hot summer the awns are small and wispy. It is grown for its illuminating sheath of fine foliage which is eventually softened by a touch of pink.
• Zebrinus AGM and Strictus AGM - The much older variety 'Zebrinus' has horizontal golden marks on leaves that arch elegantly away from the stem. The much newer 'Strictus' has stronger horizontal banding, plus a rigidly, upright shape. The latter could make a good feature plant in gravel but it lacks the grace of 'Zebrinus'. Unfortunately the two are becoming confused in the trade.

• Miscanthus sinensis var. condensatus 'Cabaret' and 'Cosmopolitan' AGM - Both of these bold grasses have broader leaves than most miscanthus in green and cream-white but the variegations are reversed. 'Cabaret' has a pale centre surrounded by a green margin and 'Cosmopolitan' has a green central zone with a creamy surround. Of the two 'Cabaret' seems more spectacular but 'Cosmopolitan' (2. 4m) wins the prize for the stature and habit. Silver-pink flowers can appear on both if you are in a hot spot.

Red or silver plume Miscanthus

There are red-plumed forms and silver-plumed forms but bear in mind that both will fade to silver within four weeks. Redder-flowered forms seem to need a warmer position to flower well.

• China': This has distinctive olive-green foliage and dark-red flowers follow - late season (5 ft/150 cm).
• Ghana' AGM: Brown flowers and brown foliage that colours up in autumn to purple (6 ft/150 cm)
• 'Malepartus': Upright purple-red flowers and broad leaves that turn pale-brown in autumn - many people’s favourite (6 - 7 ft/2m).
• 'Pünktchen': This miscanthus has wide foliage marked in a pale stripe and pale-pink flowers - stands out well in autumn (4 ft/120 cm).
• 'David': A new one with startling autumn foliage in shades of red-orange with red flowers (5 ft/150 cm).

Silver-plumed varieties of Miscanthus

Silberfeder AGM

 Dismissed by many nurserymen as it’s one of the oldest varieties, but this majestic miscanthus flowers reliably every year in August even in cold districts. Substantial silver plumes overwinter well (6 -7 ft/2m).

Kleine Fontane AGM

 Technically the drooping flowers open silver-pink but soon fade to silver - literally small fountain. (4 ft/ 120 cm).

Yakushima Dwarf

 The wide-open brownish flowers of this miscanthus are held almost in the foliage so this grass has a unique habit - being quite squat (3 - 4 ft /120 cm).

Maintenance

• Miscanthus heads tend to get shabby by the end of January and this is the best time to cut them down because they begin to reshoot inside the old stems early in the year.
• If you plan to lift or divide do this in spring just as plants shoot back into life.
• Miscanthus foliage can make a glorious background for tulips.

Tall perennials and grasses to plant with miscanthus

Piet Oudolf popularised Pagel’s grasses and developed an influential style called naturalistic planting. He combines swathes of grasses with late-season perennials. The following will match the height of most miscanthus.

1. Ratibida pinnata

A clump-forming non-invasive yellow daisy with drooping yellow petals framing a dark middle.

2. Molinia caerulea subsp. arundinacea 'Transparent'

This darkly beaded grass looks has small black beads and these shine in autumn light,

3. Sanguisorba officinalis 'Cangshan Cranberry'

From Marchant Hardy Plants, this mulberry-red sanguisorba flowers in autumn - producing dark bobbles.

4. Aster laevis 'Calliope'

Dark, almost black leaves and stems and large lavender-blue flowers in September.

5. Vernonia arkansana (previously V. crinita)

A North-American aster lookalike with tight heads of purple flowers - also in September.

6. Helianthus 'Lemon Queen'

A dark-centred lemon daisy and one of the few that will stay in a tight clump.

7. Monarda 'Squaw'

A red monarda with attitude. The stiff stems provide a good seed head and this plant is robust enough not to disappear in wet winters and strong enough to compete with tall grasses.