What can I grow in a coastal garden with salt spray?
What salt-laden wind does to leaves and soil, the plants that shrug it off, and how to build shelter in stages so a garden can develop behind it.
- Difficulty
- beginner
- Time
- 25 min
- Read
- 4 min
Short answer
Salt spray burns leaves and accumulates in free-draining sandy soil. The plants that cope have waxy, hairy, leathery or succulent leaves and low flexible growth: sea buckthorn, tamarisk, escallonia, griselinia, olearia, elaeagnus, hebe, euonymus, cistus, eryngium, armeria, crocosmia, red hot poker and most ornamental grasses. Build a permeable shelter belt first and the range of what you can grow behind it widens enormously.
Coastal gardening is wind gardening with an extra factor. Salt arrives as fine spray carried inland on the wind, deposits on leaves and draws water out of them, and washes into light sandy soil where it accumulates. The compensation is real: coastal gardens are usually milder, later to frost and earlier to spring, so once shelter exists a remarkable range of plants becomes possible.
Step by step
- Work out how exposed you actually are.Direct salt spray on a front line clifftop is a different problem from a garden half a mile inland behind houses. Salt deposition falls off quickly with distance and shelter, so be honest about which situation you are in before restricting your choices.
- Build the shelter belt first.Everything else follows from this. A permeable barrier — a tough hedge, slatted fencing or windbreak netting at around fifty per cent permeability — slows the wind over a long distance without turbulence. Solid walls and fences make it worse.
- Use the front-line species for the outer layer.Sea buckthorn, tamarisk, escallonia, griselinia, olearia, elaeagnus, euonymus japonicus, hippophae, pines and gorse. These take salt directly and shelter what is behind them.
- Plant in layers, working inwards.Toughest on the seaward side, then a middle layer of hebes, fuchsia, cistus, brachyglottis and rosemary, then the ornamental garden behind. Each layer makes the next possible.
- Recognise the leaf types that survive.Waxy and leathery, like griselinia and euonymus. Hairy or grey, like brachyglottis and olearia. Succulent, like sedum and armeria. Narrow, like grasses and pines. Large soft leaves shred and scorch.
- Choose coastal perennials.Eryngium, armeria, crocosmia, kniphofia, agapanthus, osteospermum, erigeron, sedum, achillea, centranthus and libertia. Many of these are native to sea cliffs or similar conditions and are entirely at home.
- Deal with the soil separately.Coastal soil is often sand or shingle, so it drains fast and holds neither water nor nutrients. Bulky organic matter as an annual mulch is the answer to both, and it needs repeating every year because it burns off fast in warm sandy soil.
- Wash salt off after a storm.After a severe onshore gale, a hose over hedges and shrubs the following morning genuinely reduces scorch by washing salt off the leaves before it draws water out of them.
- Plant small and stake low.As with any windy site, small plants establish far better and low staking produces stronger stems.
- Plant in autumn.Coastal soil is mild and moist in autumn, and roots make real progress over winter, which matters enormously before the first summer of drying wind.
- Use temporary netting for the first two years.Windbreak netting on posts around a new hedge until it is established makes the difference between a hedge and a row of dead sticks.
- Take advantage of the mildness.Frost is rare and late in many coastal gardens, so once shelter exists, tender plants that would fail inland — echiums, agapanthus, cordylines, some palms and many South African and Australasian plants — become genuinely possible.
Tips
- The shelter belt is the garden. Nothing else you do matters as much, and everything else becomes easier once it exists.
- Look along the coast at what is thriving in gardens and on cliffs nearby. It is the definitive local list.
- Salt burn shows as brown scorched leaf margins on the seaward side, worst after a storm, and it looks alarming — most tough plants recover.
Common mistakes
- Building a solid wall or fence for shelter — Wind lifts over it and crashes down behind, creating a turbulent zone that is often worse than no barrier at all. Permeable is what works.
- Planting the ornamental garden before the shelter — It fails, is replaced, and fails again. Plant the shelter belt in year one and accept that the garden proper starts in year three.
- Assuming all coastal gardens need the same plants — Half a mile inland behind other houses is a completely different situation from a clifftop. Do not restrict yourself unnecessarily.
- Watering lightly on sandy coastal soil — It drains almost instantly. Deep infrequent watering and a thick annual mulch are what work.
Questions people ask
What is the best hedge for a seaside garden?
Griselinia, escallonia, elaeagnus and euonymus japonicus for a garden hedge; sea buckthorn, tamarisk and gorse for a tough outer shelter belt. All of them take salt wind that would kill beech or box.
Will salt damage my soil?
In free-draining sandy coastal soil, rain washes it through fairly quickly. In heavier soil or in a very exposed spot it can accumulate, and generous organic matter improves the soil's ability to cope.
Can I grow vegetables by the sea?
Yes, behind shelter, and the mild climate is a real advantage for early and late crops. Wind is the limiting factor rather than salt for most vegetable gardens, so netting or a hedge on the seaward side is the first job.