Why the Coast Tests Plants Harder

A garden within a mile or two of the sea lives with conditions that inland gardeners rarely have to think about. Wind arrives constantly, often carrying a fine mist of salt that draws moisture out of leaves and scorches them brown at the edges. Where the wind funnels between buildings or along a promenade, it can be strong enough to snap stems and strip blossom in a single afternoon.

Soil adds its own complications. Many coastal plots sit on sand, shingle or thin soil over chalk or rock, which drains fast and holds very little in the way of nutrients. Inland gardens may be wetter, but coastal soil is often dry by June and bone-dry by August. The good news is that plants adapted to these conditions thrive here, and a seaside border planted with the right choices can look far better than a fussy inland one that constantly needs watering.

Salt-Tolerant Stars for Windy Borders

The trick is to choose plants with tough, often leathery or narrow leaves, and to accept a slightly windswept look as part of the charm. These reliably cope with spray, drought and salt-laden air:

• Sea thrift (Armeria maritima) — neat cushions of grassy foliage topped with pink drumstick flowers from late spring. Perfect at the front of a border or edging a path.
• Lavender — Lavandula angustifolia varieties such as 'Hidcote' are superb in free-draining coastal soil and smell wonderful on a warm evening.
• Tamarisk (Tamarix ramosissima) — a tough, airy shrub or small tree with feathery grey-green foliage and soft pink flower spikes in late summer. It shrugs off strong wind better than almost anything else.
• Sea holly (Eryngium) — steel-blue thistle-like heads that hold their shape and colour well into autumn.
• Rosemary and santolina — aromatic, drought-proof evergreens that give structure through winter.
• Escallonia and Griselinia littoralis — excellent for a windbreak hedge, both happy with salt and clipping.
• Red valerian, stonecrop (Sedum), hardy geraniums and crocosmia — generous self-seeders and spreaders that knit a border together quickly.

For late-season interest, add Nerine bowdenii and autumn alliums; both enjoy the sharp drainage a coastal garden offers.

Building Shelter Without a Solid Wall

The instinct on a windy plot is to build a tall solid fence, but this often makes things worse. Solid barriers force wind up and over, creating fierce turbulence on the sheltered side. A better approach is a permeable barrier that filters roughly half the wind — slatted fencing, woven willow hurdles, chestnut paling or a mixed hedge.

Aim to slow the wind rather than stop it, and you create a calm pocket extending about five times the height of the barrier downwind. If your boundary already has a wall, plant a hedge or tall shrubs a metre or so inside it to soften the eddies. Position your most delicate plants in these lee pockets, close to the house, behind a shed, or between two sturdy shrubs. Even a single robust windbreak planting can transform which plants will grow for you.

Making Sandy Soil Hold On to Moisture

Sandy and shingly soils drain within minutes, which suits lavender and thyme but leaves most other plants struggling by midsummer. The answer is organic matter, added generously and repeatedly.

• Spread 5–8cm of well-rotted compost or manure over the surface each spring and let the worms work it in, rather than digging it deep.
• Use leaf mould as a mulch around shrubs — it holds water like a sponge and slowly feeds the soil.
• If your plot is very light, work in a loam-based topsoil when planting individual shrubs, mixing it with the existing sand rather than creating a pot-shaped pocket.
• Seaweed gathered from the strandline (rinsed first) is a traditional coastal mulch and soil conditioner.
• Avoid high-nitrogen feeds, which produce soft, sappy growth that wind tears apart.

Mulching also suppresses weeds and stops the surface from drying into a crust, which helps rainfall actually reach the roots.

Planting, Watering and Year-Round Care

Autumn is the best time to plant in coastal gardens, while the soil is still warm and winter rain does the watering for you. Avoid planting into dry sand in midsummer unless you are prepared to water daily for several weeks.

Water new plants thoroughly for their first two summers — this is the single most common reason seaside plantings fail. Once established, most of the plants listed above need little supplementary water. Trim lavender and santolina lightly after flowering in late August, but never cut back into old, leafless wood. Cut tamarisk back hard in early spring if it becomes leggy, and give hedges their main tidy in late summer so the cuts have time to harden before winter gales.

Small Coastal Gardens and Containers

If you garden on a balcony, terrace or a tiny front plot, containers give you control over both soil and shelter. Choose large, heavy pots — terracotta or glazed ceramic — so they are not blown over, and use a loam-based compost mixed with a third grit for drainage. Group pots closely together; they shelter one another and the display looks fuller.

Thrift, lavender, rosemary, sedum and sea holly all grow happily in pots for years, needing only a top-dressing of fresh compost each spring. Place them against a wall for extra protection, and you will have a seaside garden that looks deliberate rather than battered.