Why grasses earn their place among wildflowers

A wildflower patch without grasses can look like a collection of individuals rather than a community. Grasses supply the matrix that holds everything together — the soft, shifting background against which the flowers read as drifts rather than dots. They also bring things flowers cannot: fine texture, winter presence, movement on the slightest breeze, and the rustle that makes a planting feel alive on a still afternoon.

There are practical arguments too. Our native grasses are caterpillar food plants for meadow brown, gatekeeper, speckled wood and wall brown butterflies, and their seed heads feed finches and buntings well into January. A planting that is grass-rich and flower-rich is simply a better habitat than one that is flower-rich alone.

Matching grasses to your soil

Start with what your ground naturally wants to grow. Trying to force a chalk mix onto heavy clay is the quickest route to disappointment.

• Light, sandy or chalky soils: sheep's fescue (Festuca ovina), blue moor grass (Sesleria caerulea) and quaking grass (Briza media). All are compact and drought-tolerant. Partner them with wild marjoram, salad burnet, kidney vetch and small scabious.
• Medium loam: crested dog's tail (Cynosurus cristatus), common bent (Agrostis capillaris) and meadow foxtail. This is the backbone of the classic English hay meadow, and it suits ox-eye daisy, knapweed and field scabious beautifully.
• Heavy clay and damp ground: tufted hair grass (Deschampsia cespitosa), purple moor grass (Molinia caerulea) and Yorkshire fog. These cope with winter wet. Try them with ragged robin, meadowsweet and purple loosestrife.
• Acid or peaty ground: wavy hair grass (Deschampsia flexuosa) and purple moor grass, underplanted with harebell, tormentil and devil's-bit scabious.

Purple moor grass deserves special mention. Its foliage is unobtrusive for most of the year, then it throws up airy flower spikes in late summer that seem to float. It is one of the finest ornamental grasses we have, and it is entirely British.

Combinations that read as meadow, not border

The trick is to plant in generous drifts and repeat them, rather than dotting one of everything about. Aim for roughly sixty per cent grasses to forty per cent flowers by volume, and leave a little bare or thinly covered ground — solitary bees and many beetles need it.

• Quaking grass with ox-eye daisy and lady's bedstraw — light soils, midsummer, softly luminous.
• Purple moor grass with knapweed and meadow buttercup — damp ground, late summer, tall and hazy.
• Tufted hair grass with ragged robin and meadowsweet — pond margins and boggy corners.
• Blue moor grass with wild marjoram and small scabious — chalk and limestone, front of planting.
• Creeping red fescue with bird's-foot trefoil and selfheal — a low, tough mix for path edges and awkward corners.

Designing for movement and winter interest

Place the airiest grasses where you will see them against low sun — the light passing through Deschampsia spikes or a stand of quaking grass in the evening is worth planning for. Keep the smallest, tidiest grasses near the front, and let taller, see-through types such as purple moor grass or tall oat grass rise behind the flowers without hiding them.

Resist the urge to tidy up in autumn. Leave stems and seed heads standing through winter: they hold structure when everything else has collapsed, catch frost beautifully, and provide cover and food for wildlife. Cut back in late February or early March, before new growth starts, and rake off the cuttings.

Planting for insects

Think of the grasses as habitat and the flowers as fuel. The grasses support the caterpillars; the flowers feed the adults, along with hoverflies, solitary bees, bumblebees and moths. Extend the season deliberately with a succession of flowers — cowslips and selfheal in spring, ox-eye daisy and bird's-foot trefoil in early summer, knapweed and field scabious in high summer, devil's-bit scabious and betony into autumn.

Single-flowered wildflowers are what you want. Doubled garden forms often offer little or no nectar, however pretty they look in a catalogue.

Keeping the balance

Grasses can outcompete flowers, particularly on fertile ground. The remedy is not to fight them but to lower the fertility: cut the meadow once a year in late summer and always remove the arisings. Compost them well away from the planting. Never feed the area, and avoid adding rich topsoil when establishing.

Yellow rattle is your best ally here. Sow it in autumn and let it parasitise the grasses, weakening them enough for flowers to establish. Thin out any grass that starts to dominate in distinct patches, and replant into the gaps with plugs. After three or four years you will have something that looks as though it has always been there — and that is the whole point.