Oh, we do love to grow beside the seaside
The key to making a success of a garden on the coast is finding plants that will be happy whatever the wind, sea and sand throw at them. John Hoyland suggests some of the best to try
COASTAL gardens in Britain are as varied as the coastline itself. Those of south-west Scotland, Devon and Cornwall are bathed in the warmth of the Gulf Stream, which keeps temperatures high enough to grow exotic plants. With that warm air comes high rainfall, something that gardeners in the dry coastal gardens of Norfolk and Suffolk can only dream about.
In the North-east and in Lancashire, coastal gardens are exposed to bitterly cold winds. Even the coldest place, however, is likely to be warmer than those inland and all seaside gardens will have higher light levels, thanks to light reflected off the sea.
Growing conditions can vary enormously within one region. Inland gardens in a particular locality usually have minor environmental differences, but, on the coast, the differences can be extreme, depending on topography, the way the wind turns or where the sun falls. Taking time to become familiar with the microclimate of any garden is important, but in a coastal one it’s essential and could mean the difference between a beautiful garden or a windswept, barren piece of land.
Although there is no generic British coastal garden, all have one certainty: wind. The more open to sea views, the more damaging the wind will be to the garden. It will bring salt to scorch leaves and sand to blast them. Plants will lose moisture through increased transpiration and establishing new plants will be difficult. A windbreak of some kind is essential.
Windbreaks do not have to be the largescale woodlands seen around sites such as Caerhays Castle in Cornwall, where an extensive shelterbelt protects the garden’s collections of magnolias and camellias—even a modest hedgerow will provide a significant amount of shelter. Favour hedges over solid barriers, such as walls and fences, as the latter will create eddies that can be more damaging than the original wind.
At Durnamuck in Wester Ross, the garden’s spectacular plant collection is protected by a row of willows on its windward edge and by a hedge of Olearia on the leeward boundary. Olearia, as is its cousin hebe, is a New Zealand shrub and both have tough, evergreen, salt-resistant foliage, ideal for hedging.
In mild areas, consider also Bupleurum fruticosum, Pittosporums and Escallonias.
On the east coast, the winds are colder, so look to tougher shrubs such as Escallonia x ebbingei and Euonymus japonicus, a plant native to the harsh coasts of Japan and extremely salt and wind tolerant. These shrubs can be pruned to a height that offers some protection to the garden without hampering any views. A filtering windbreak will significantly reduce wind on its leeward side for up to a distance of 10 times its height.
Once areas are relatively free from wind, the range of plants that can be grown is wide. The floral exuberance of gardens such as Inverewe in the west of Scotland or East Ruston in Norfolk contradict the misconception that it’s difficult to create a flower-filled garden close to the sea. As well as being at opposite ends of the country, these gardens have very different conditions to contend with. Inverewe has more than 50 inches of rain a year, East Ruston barely 20, yet both are a source of design and planting inspiration. Although on a different scale, even the shingle of the inhospitable landscape around
Derek Jarman’s Prospect Cottage at Dungeness in Kent sustains the bright flowers of eschscholzia, scabious, santolina, valerian, lavender and every kind of poppy.
Wherever you are in the country, if you want to grow more than sea hollies, sea campion and sea kale, you will have to improve the soil. Digging in lots of organic matter before planting and regularly mulching will improve fertility, help retain moisture and broaden the plant palette that is available to you. Agapanthus, crocosmia and kniphofia, stalwarts of coastal gardens, have a reputation for growing in poor situations, but to thrive and flower well the soil needs to be fed.
The best way to choose plants for your own plot is to have a snoop around other gardens in the immediate vicinity to see what is thriving. If there is a nearby nursery, visit it and seek advice. It is there that you will discover a wider range of plants and the plants locals grow are likely to be better adapted to your climate than those imported from afar. Twenty years ago, restios, South African reeds, were unknown in Britain and it’s thanks to specialist nurseries that their elegant, grass-like foliage is now gracing many seaside gardens.
Search out plants native to coastal sites. The Chatham Island forget-me-not, Myosotidium hortensia, has leathery glossy leaves and sprays of sparkling blue flowers whose delicacy conceals toughness. From the same
area, Astelia chathamica has imposing silver spears that are at their best when grown in shade. Look out, too, for cultivars and hybrids of common seaside plants. Berberis Orange Rocket has flame-coloured foliage; on B. Maria, the leaves are a buttery yellow.
Hebes have also been the subject of breeding programmes and there are now several
forms in nurseries with eye-catching foliage. My favourite is Hebe Pascal, which stays deep purple throughout winter. Coastal gardens can be as floriferous as inland ones, with the added bonus of spectacular views and the sound of the sea.
John Hoyland is gardens advisor at Glyndebourne, East Sussex
If you want to grow more than sea hollies, sea campion and sea kale, you will have to improve the soil