Why grasses suit the seaside better than most plants

Few plants look as at home on a blustery coastal plot as ornamental grasses. Their stems bend rather than snap, their foliage sheds salt spray quickly, and their habit of swaying in the wind turns a problem into a feature. On a garden that faces the sea, where wind scorches leaves and dries out soil faster than you can water it, grasses earn their place.

The trick is choosing the right ones. A Festuca glauca that looks charming in a sheltered courtyard will sulk and rot in a salt-laden gale, while a Leymus arenarius that shrugs off the same conditions would look thuggish among delicate perennials. Matching the grass to the exposure is the whole game, and it is far easier than many gardeners expect.

Understanding what the coast throws at your plants

Before you buy a single pot, it helps to know what you are planting into. Coastal gardens deal with a particular combination of stresses that inland plots rarely face all at once.

• Salt spray — carried by wind for miles inland. It burns leaf margins, blocks stomata and can leave a white crust on foliage after a storm.
• Constant wind — desiccates leaves, snaps brittle stems and topples shallow-rooted plants.
• Free-draining soil — often sandy or stony, holding little moisture and few nutrients.
• Bright, unfiltered light — glorious in summer, but punishing for plants with soft, thin leaves.

Grasses have evolved in exactly these conditions on dunes, cliff tops and steppes. Give them a free-draining root run, full sun and a bit of shelter at ground level and they will repay you handsomely.

Reliable grasses for exposed, salty positions

The safest choices are those with tough, narrow, often blue-grey or glaucous leaves. That colour is not just decorative — the waxy bloom reflects light and helps the plant resist salt and drought.

• Leymus arenarius (blue lyme grass) — the classic dune grass. Bold, upright, blue-grey and utterly unbothered by wind. It spreads by rhizomes, so give it room or sink a barrier.
• Festuca glauca and its cultivars — compact blue fescues that form neat tussocks. Superb at the front of a border or in gravel. They dislike winter wet, so plant them on a slope or in sharp drainage.
• Stipa tenuissima — fine, blonde, endlessly mobile. Surprisingly hardy once established, though it resents cold, wet roots.
• Anemanthele lessoniana (pheasant's tail grass) — evergreen, arching, with orange and bronze winter tints. Tolerates wind and poor soil beautifully.
• Deschampsia cespitosa — tussocky, dark green, with airy panicles that catch every gust. It copes with damper coastal hollows too.
• Calamagrostis × acutiflora 'Karl Foerster' — stiff, vertical, and reliably upright even in a stiff breeze.

If your garden is right on the shoreline, lean heavily on the first three. A few rows back, where a hedge or fence breaks the worst of it, you can widen your palette considerably.

Planting and establishing in a windy garden

Getting grasses through their first year is the difference between a display that lasts a decade and one that vanishes by autumn. Plant in spring, once the soil has warmed, so roots have the whole growing season to settle before winter gales arrive.

Dig a hole wider than the pot but no deeper, and incorporate plenty of garden compost or well-rotted manure to hold moisture in sandy ground. Set the crown level with the surrounding soil — bury it and the plant will rot. Firm gently, water well, and mulch with gravel or bark to conserve moisture and suppress weeds.

Newly planted grasses need protection from wind for the first season. A temporary windbreak of horticultural fleece, or even a few bamboo canes with netting, makes an enormous difference. Once roots are deep, you can take it away. Remember to water through the first summer, especially during dry, windy spells when plants lose moisture faster than they can replace it.

Feeding, cutting back and dividing congested clumps

Coastal grasses are not hungry plants. In fact, overfeeding makes them soft, floppy and far more likely to suffer wind damage. A light dressing of a balanced slow-release fertiliser in spring is plenty for most; on richer soils, you can skip it entirely.

The main annual job is the chop. Deciduous grasses such as Calamagrostis and Deschampsia should be cut hard back to about 10cm in late winter or early spring, just before new growth appears. Evergreens like Anemanthele and Festuca only need a gentle tidy — comb out dead foliage with gloved hands or a small rake, and never cut into the woody crown.

After three or four seasons, most clump-forming grasses become congested. The centre dies out, flowering declines and the plant starts to flop. This is your signal to divide.

• Time it right — divide in early spring as growth restarts, or in early autumn while the soil is still warm.
• Lift the whole clump with a fork, working around the perimeter to avoid slicing roots.
• Split with two forks back to back, or use a sharp spade for tough, fibrous crowns.
• Discard the woody centre and replant the vigorous outer sections.
• Water generously and keep divisions shaded for a week or two until they settle.

Dividing does double duty: it rejuvenates tired specimens and gives you free plants to fill gaps or pass on to neighbours. On exposed sites, replant divisions slightly deeper than before and surround them with a little gravel to keep the crown dry.

Building a planting that reads well in the wind

Grasses look best when they are allowed to play off each other and against contrasting shapes. Pair upright forms like Leymus and Calamagrostis with rounded, low-mounding plants such as lavender, sea thrift or santolina. Add a few taller, wind-firm evergreens behind them — Olearia, Escallonia or a hardy Pittosporum — to give the border a backbone and shelter the grasses in front.

Do not aim for neat symmetry. Coastal planting works best when it looks slightly informal, as though the garden has grown into its setting. Let the wind do the arranging.

Choose tough varieties, plant them well, and be ruthless with the secateurs every few springs. Do that, and your seaside grasses will reward you with movement, texture and colour long after the summer flowers have faded.