<em>Pennisetum</em>: 7 ideas for combining them

In dry rockery

In a rock garden, bottlebrush herb will be perfect when paired with pretty low-growing plants that, like it, love heat and tolerate summer drought well. It will find its place easily alongside autumn sedums, Eryngium planum ‘Blue Hobbit’, small grasses such as Bouteloua gracilis, Festuca glauca ‘Golden Toupee’, as well as thymes and creeping sedums. Also consider Coreopsis and Spanish grass for a romantic touch; in that case opt for the Pennisetum orientale ‘Karley Rose’ with silky pale-pink flower heads, washed with purplish-pink. It will be perfect with small hardy asters and chrysanthemums, perennials with autumn flowering.

Pennisetum orientale ‘Karley Rose’, Coreopsis ‘Limerock Passion’, Armeria maritima, Eryngium planum ‘Blue Hobbit’ and Sedum spectabile ‘Stardust’

In naturalistic beds

Silky, airy tufts of Pennisetum let you introduce natural movement into a large border while admiring their textural and luminous effects. Choose the tallest varieties, a Pennisetum alopecuroides ‘Japonicum’ or aPennisetum macrourum planted mid-border or at back of borders, to which they give a vapourous, quivering relief.

Pennisetum pairs easily, coming in as pit, with other summer flowering perennials. In a lush, country-style composition, pair it with rambling plants, such as Achillea (Achillea filipendulina ‘Golden Plate’), Agastaches, Gauras and eupatoriums, or with tall perennials such as Perovskias or Buenos Aires verbenas, whose habit it will soften. It will accompany floriferous and airy perennials, such as penstemons, Asters (Aster laevis ‘Calliope’, Aster turbinellus, Aster cordifolius), scabious or Nigella damascena. It lightens flowering of heavier perennials such as dahlias, Echinaceas or Oriental poppies.

In a predominantly pink palette, the Pennisetum thunbergii with its red flowering harmonises beautifully with large sedums, small red flowers of shrubby sages and those of purple amaranths such as ‘Velvet Curtains‘. Make the most of its long flowering by pairing it with Japanese anemones.

Punctuate these natural scenes by pairing pennisetum with clumps of Calamagrostis brachytricha or Feather Reed Grass, Stipa tenuifolia and why not a majestic pampas grass.

Pennisetum macrourum, Agastache ‘Black Adder’, Nigella damascena, Eupatorium maculatum ‘Atropurpureum’, Aster cordifolius ‘Idéal’

Along the path

Low-growing varieties can be planted along path edges. Choose, for example, a Pennisetum alopecuroides ‘Hameln’ with white spikes tinged with brown, a reliable choice that stays compact and does not spread, or a Pennisetum alopecuroides ‘Cassian’. The small red bunny tails of ‘Red Bunny Tail’ close to Allium sphaerocephalon, the blue flowering of Nepetas or perennial salvias, a few clumps of Stipa arundinacea, and Lavender also make a splendid display. You can alternate with other grasses, wavy hair-grass, Festuca mairei or Eragrostis spectabilis, which will accompany them at the slightest breeze.

Pennisetum alopecuroides ‘Hameln’, Stipa arundinacea, Lavender, Nepeta ‘Six Hills Giant’, Eragrostis spectabilis

In a wild garden

Magnificent in a wild garden, pennisetum displays its colourful, feathery spikes right through to autumn. Once faded, they make a splendid feature through to winter. That is why it is an essential plant in naturalistic prairies, where it will bring vibrant poetry. Choose a Pennisetum alopecuroides that readily self-seeds without ever becoming invasive.

Plant it in large drifts; it fits perfectly alongside meadow flowers. Its spikes will provide a contrasting shape to the broad, flat inflorescences of achilleas, large oxeye daisies, and big perennials such as hybrid mulleins, Acanthus spinosus, Cephalaria gigantea or more wayward plants such as California poppies, hollyhocks and Dipsacus sylvestris. We also recommend pairing it with large asters (Aster turbinellus, Aster laevis), Panicum virgatum, and Stipa gigantea to complete a pretty wild scene.

Pennisetum incomptum, hollyhocks, teasel, Verbascum, Panicum virgatum ‘Squaw’

In a contemporary garden

With finely textured foliage of infinite lightness and graphic quality, Pennisetum is also a wonderful structural plant to create a pared-back setting in a very contemporary style. It has its place in a minimalist setting in a dry garden. In that spirit, you can bring together Pennisetum setaceum ‘Skyrocket’, a variegated variety, with a Phyllostachys aureosulcata ‘Aureocaulis’, and other large wild herbs such as Stipa tenuifolia, Miscanthus, Mulhenbergia rigens and Panicum virgatum ‘Blue Darkness’.

In a mineral scene, it will be showcased surrounded by pebbles or white gravel, Allium, a Hydrangea ‘Golden Annabelle’, two or three ball-shaped boxwoods and medium-sized phormium.

Pennisetum setaceum ‘Skyrocket’, Muhlenbergia rigens, Stipa tenuifolia, Panicum virgatum ‘Blue Darkness’, Phyllostachys aureosculata ‘Aureocaulis’

Groundcover

Pennisetum incomptum is a species often used to stabilise dry slopes. It develops from a vigorous rhizomatous stump and eventually forms tall, erect clumps over one metre, widening with age. Ideal for colonising large, slightly wild spaces, tolerant of wind and sea spray. Pair with other large grasses such as Panicum virgatum, Miscanthus sinensis, pampas grass, as well as vigorous bushes and perennials such as perovskias, large thistles (Onopordum nervosum et Berkheya purpurea), Cytisus scoparius, cistus, lavender and rosemary.

Pennisetum incomptum, Onopordum nervosum, Rosemary, Cytisus scoparius ‘Palette’, rockrose

Potted in sun

Some pennisetum are not hardy at all (-5 °C to -10 °C) and are most often used as annual plants in summer pots, such as Pennisetum setaceum ‘Rubrum’, entirely coloured deep purple to chocolate. Pennisetum alopecuroides ‘Goldstrich’ is a compact, distinctive and very hardy variety that also succeeds in large sunny containers. They can accompany summer-flowering annuals (red linums, cosmos, nigellas, Diascias) or gently envelope the bases of dahlias or a golden Cordyline to contrast the scene.

Pennisetum alopecuroides ‘Goldstrich’, Diascias, Pennisetum setaceum ‘Rubrum’, Cordyline obtecta ‘Superstar’, Dahlia ‘Happy Single Kiss’