Why coastal winters bite harder

Coastal gardens come with a particular set of winter challenges. You may not see the deep, lingering frosts that settle inland, but wind and salt spray more than make up for it. A plant that would shrug off a cold snap in a sheltered town garden can be scorched, stripped and snapped by a single December gale blowing straight off the sea. Understanding what is actually doing the damage lets you target your protection properly, rather than wrapping everything in sight.

• Salt spray rides on the wind, burning foliage, desiccating buds and leaving a film on leaves and stems that sets tender growth back for months.
• Wind buffets plants relentlessly, loosening rootballs, shredding evergreen leaves and drying foliage even when the soil beneath is wet.
• Free-draining sandy soil holds little moisture, so winter rain runs straight through and roots can go thirsty in the middle of a wet month.
• Frost pockets hide behind dunes, walls and hedges, where calm, clear nights can still deliver a sharp, damaging frost.

Read your plot before you wrap a single plant

Every coastal garden has its own microclimate, and a bit of observation now saves a lot of heartache later. Walk round on a windy day and watch where the gusts funnel between buildings, and where the hedge breaks their force. Notice the windows that end up crusted with salt after a storm, because those are the spots where spray lands hardest. The front line, facing the prevailing wind, is almost always the toughest position in the garden.

Then be honest about which plants are genuinely tender. Anything with soft, sappy growth, thin evergreen leaves, or a tropical look will need help. So will plants in containers, whose roots freeze far more quickly than those in the ground, and any recent planting that has not yet rooted out into its surroundings. Newly bought specimens are often the first casualties of a coastal winter.

Windbreaks: your first line of defence

If you do only one thing, build a windbreak. A solid fence or wall simply forces the wind up and over, creating damaging turbulence on the sheltered side and eddies that tear at plants. What you want is a permeable barrier that filters the wind and slows it down. Something around half porous is ideal.

Permanent planting is the best long-term answer. Salt-tolerant evergreens such as Griselinia littoralis, escallonia, Olearia and tamarisk will grow into a living screen that shelters everything behind it. Allow them to establish for a few seasons before you rely on them, and clip lightly rather than hard, since a densely clipped hedge loses some of that useful porosity.

For instant protection, temporary hurdles work well. Woven willow or hazel panels, or mesh windbreak fabric stapled to sturdy posts, can be moved around as the season demands. Push the barrier far enough away from the plants you are sheltering: if it hugs them too closely, the air behind it stagnates and you swap wind damage for mould.

Fleece, wraps and cloches for tender growth

Horticultural fleece is the coastal gardener's most useful winter tool. It traps a layer of still air around foliage, keeping temperatures a couple of degrees higher and shielding leaves from salt-laden wind. Double up the layers for really tender specimens, and check that the fleece is pegged or weighted down firmly so a gale cannot whip it away in the night.

• Tree ferns and bananas: pack the crown with dry straw, then tie fleece over the top, leaving the trunk exposed to drain.
• Palms and cordylines: draw the fronds up and tie them loosely, then wrap the growing point rather than the whole trunk.
• Pots and containers: group them together against a south-facing wall, raise them onto pot feet and wrap the rootball in bubble wrap or hessian.
• Low plantings: use cloches or a cold frame for alpines and small tender shrubs, opening them on mild days to let air circulate.

Avoid plastic sheeting laid directly over foliage, as it traps condensation and encourages rot. And do peel back the covers on calm, mild days when you can, because plants under fleece for weeks on end become pale, soft and far more vulnerable when the cover finally comes off.

Mulch, drainage and salty soil

A generous mulch does two jobs on the coast: it insulates roots against frost and it stops the wind from drying the soil surface. Spread five to eight centimetres of bark, composted green waste or well-rotted manure over the beds, keeping it clear of stems and crowns so nothing rots at the base.

For Mediterranean plants such as lavender, rosemary, cistus and agapanthus, a gravel mulch is better still. It keeps the crown dry and reflects light, which suits plants that hate winter wet far more than they hate cold. If you garden on sand, water thoroughly during mild, dry spells, since a thirsty plant is a vulnerable one. Do not feed now; soft, leafy growth produced in winter is the first thing a frost will destroy.

Winter checks and clearing up after gales

Once everything is tucked in, the work is mostly watching and reacting. Check ties on climbers and young trees before the worst weather arrives, and firm back any plants lifted by frost heave. Knock heavy snow off evergreens with a soft broom before branches bend or break. After a salt-laden storm, hose down foliage if the ground is not frozen, as this washes the worst of the spray away.

Resist the urge to cut storm-damaged wood straight away. Leave the ragged stems until spring, when they will protect the growth below, then tidy them with clean secateurs once the risk of hard frost has passed. Above all, be patient with brown, battered foliage. Coastal plants are tougher than they look, and many a scorched-looking shrub will push out fresh shoots in April. Give it until early summer before you decide its fate.