The best ornamental grasses for borders
The best ornamental grasses for borders are reliable, clump-forming plants such as Calamagrostis × acutiflora 'Karl Foerster', Molinia caerulea, Deschampsia cespitosa, Sesleria autumnalis and Hakonechloa macra. They bring movement, light and structure, partner beautifully with flowering perennials and often look good from summer right through winter. Choosing the right one comes down to your soil, light and the effect you want.
Why grasses belong in a border
Grasses do things that flowering perennials cannot. They sway in the slightest breeze, catch low autumn sunlight, and hold their shape long after flowers have faded. In a mixed border they act as a calm backdrop, linking brighter plants together and giving the eye somewhere to rest. Most of the grasses below are well behaved, clump-forming and happy in average garden soil.
Upright grasses for structure
Calamagrostis × acutiflora 'Karl Foerster'
Perhaps the most dependable border grass of all. It forms a tidy clump with narrow, vertical flower stems that turn from bronze to straw gold and stand well into winter. Use it repeated through a border for rhythm. It grows to around 1.5 to 1.8m and is happy in most soils, including clay.
Panicum virgatum
Switch grass offers upright clumps with clouds of tiny flowers in late summer, and many forms colour beautifully in autumn. 'Shenandoah' turns rich red, while 'Heavy Metal' has blue-grey foliage. It prefers full sun.
Miscanthus sinensis
For larger borders, miscanthus brings real presence, with arching leaves and feathery plumes in autumn. 'Morning Light' is finer and more compact, with narrow, white-edged leaves. Give it space, as clumps become substantial over time.
See-through grasses for movement
Molinia caerulea
Purple moor grass is one of my favourite grasses for naturalistic schemes. Molinia caerulea subsp. caerulea 'Moorhexe' is neat and upright, while Molinia caerulea subsp. arundinacea 'Transparent' sends up tall, airy flower stems you can see straight through. Both turn lovely shades of butter yellow in autumn and are happy in moist, acidic or neutral soils.
Deschampsia cespitosa
Tufted hair grass forms low, evergreen tufts topped with shimmering clouds of tiny flowers in early summer. 'Goldtau' is compact and golden as the flowers mature. It is tolerant of shade and heavier, damp soils, which makes it unusually versatile.
Stipa gigantea
Golden oats sends tall, see-through stems topped with oat-like flowers well above a low evergreen clump. Plant it near the front of a border so you can look through it to the plants behind. It needs sun and good drainage.
Low grasses for edges and ground cover
Sesleria autumnalis
Autumn moor grass makes a fresh, lime-green carpet that looks good for most of the year. It is excellent as a matrix plant, planted in numbers with perennials rising through it, and copes with sun or light shade.
Hakonechloa macra
Japanese forest grass forms soft, cascading mounds and is one of the best grasses for partial shade. It is slow to establish but well worth the wait, and looks wonderful spilling over path edges or in pots.
Anemanthele lessoniana
Pheasant's tail grass is evergreen, with arching foliage that takes on orange and bronze tones, particularly in cooler weather. It is a good choice for dry shade and adds warmth in winter.
Planting partners
Grasses shine when paired with flowering perennials of contrasting shape. Try Calamagrostis with the spires of Veronicastrum or Salvia, or Molinia and Deschampsia with my favourite Sanguisorba 'Cangshan Cranberry' and 'Tanna'. Daisy flowers such as Echinacea and Rudbeckia look wonderful against a backdrop of Panicum. For more on building schemes like this, see naturalistic planting explained.
Caring for ornamental grasses
Most border grasses are deciduous, meaning their stems die back for winter. Leave them standing for structure and wildlife, then cut back to a few centimetres above the ground in late winter or early spring, before new growth starts. Evergreen grasses such as Stipa gigantea, Deschampsia and Anemanthele should not be cut hard; simply comb out dead leaves with gloved hands and remove old flower stems. Divide large clumps in spring, just as they begin to grow.
Choosing grasses at a glance
Upright structure: Calamagrostis 'Karl Foerster', Panicum virgatum.
See-through movement: Molinia, Deschampsia, Stipa gigantea.
Low edges and ground cover: Sesleria autumnalis, Hakonechloa macra.
Shade: Hakonechloa, Deschampsia, Anemanthele.
Cut back deciduous grasses in late winter; comb out evergreens.
Plant and divide in spring for the best establishment.
Quick answers
When is the best time to plant ornamental grasses?
Spring is ideal for most grasses, as they establish quickly in warming soil. Many can also be planted in early autumn while the soil is still warm.
Which ornamental grasses are best for clay soil?
Calamagrostis 'Karl Foerster', Deschampsia cespitosa, Molinia caerulea and Panicum virgatum all grow well in heavier soils.
Do ornamental grasses spread?
The grasses listed here are clump-forming and grow slowly outwards rather than running through the border. Some, such as Stipa tenuissima, can self-seed freely.
