Autumn by the Sea Means Something Different

If you garden within sniffing distance of the brine, you already know that autumn doesn't behave the way it does inland. The light softens, the crowds thin, and the wind picks up. Salt-laden gales strip moisture from leaves, whip at anything tall and leggy, and leave a fine white crust on glass and foliage alike. Coastal soils are often thin, sandy and free-draining, holding little water and even less goodness. The compensation is a long, mild growing season and a plot that rarely freezes solid. Autumn is the moment to bank those advantages and batten everything down before the weather turns properly wild.

Shelter First: Tie, Stake and Trim

Wind damages more coastal plants than cold ever will, so shelter comes before everything else. Spend a dry afternoon walking the garden with a pocketful of twine and a sharp pair of secateurs, and deal with anything that could act as a sail.

• Re-firm stakes and replace worn tree ties, leaving a little room for the trunk to swell. A tree that rocks in a gale tears its own roots.
• Shorten long, whippy growth on roses, buddleia and escallonia by about a third to reduce windrock, but leave the main framework alone.
• Patch gaps in hedges and windbreaks now. Brushwood, hazel hurdles or even a temporary net screen will knit a hole together until spring.
• Group pots together in the lee of a wall or fence. Plants shelter one another, and a huddle of containers is far less likely to blow over than a lone one.

Feed the Soil Before the Winter Rains Arrive

Sandy coastal ground leaches nutrients straight through, so a good autumn mulch is worth more here than almost anywhere else. Wait until the soil is damp from a decent shower, then spread a generous layer.

Five to eight centimetres of well-rotted compost, leafmould or spent mushroom compost will insulate roots, slow evaporation and feed the worms that do your digging. Seaweed is a superb coastal mulch, rich in potash and trace elements, but give it a quick rinse if it is straight off the beach and never smother the crowns of plants with it. Keep mulch clear of stems and trunks to avoid rotting them off over winter. And hold back on high-nitrogen feeds from now on — soft, sappy growth is exactly what a salt wind shreds first.

Tuck Up Tender and Borderline Plants

Mild coastal winters lull you into leaving things out that a single sharp gale will finish off. Move pots of agapanthus, olives, citrus and young palms into a porch, greenhouse or against a south-facing wall, and raise every container onto pot feet so water drains freely.

• Wrap tree ferns and cordylines with horticultural fleece or hessian, and pack the crown of a tree fern with dry straw.
• Lift dahlias, gladioli and other tender corms once foliage blackens, dry them somewhere airy, and store in trays of dry compost.
• Use cloches or doubled fleece over borderline shrubs, but take it off on mild, still days to prevent mould.
• Ease off watering in pots. Cold and wet kills more coastal container plants than frost ever does.

Clear, Drain and Repair Before the Gales

Coastal rain arrives sideways and in quantity, so drainage is a winter job done in autumn. Clear fallen leaves from gullies, gratings and pathways, and check that gutters and water butts are flowing properly. Empty saucers, tip water out of anything that has collected it, and sweep paths of slippery algae and salt residue.

Cut back spent herbaceous perennials, but leave seedheads on sedums, teasels and sea holly for the birds and for a little structure in the bare months. Bin any diseased foliage rather than composting it. Then walk the boundaries: check fence posts, gate hinges, greenhouse panes and cloches, and secure anything loose while you can still feel your fingers.

Plant Now for a Better Spring

Autumn is the best planting window a coastal garden gets — the soil is still warm, the rain does your watering, and roots settle in before the winds arrive in earnest. Bare-root hedging such as hawthorn, blackthorn and sea buckthorn establishes quickly and doubles as a shelterbelt. Plant garlic, broad beans and hardy winter salads, and get narcissi, alliums and crocus into the ground for naturalising in rough grass. Roses, too, settle beautifully from bare root now.

Choose wind- and salt-tolerant plants where exposure is fiercest — sea thrift, eryngium, lavender and escallonia all shrug off the spray. Water new plantings in well, mulch around them, and stake anything with height. Do this groundwork now and your seaside plot will come through winter with its bones intact and its soil ready for a generous spring.