Seaside gardens battle the wind, salt spray and soil erosion, but with the right plant choices, these spaces can be beautiful throughout the year
June 8 is World Oceans Day, a day observed internationally that recognises the importance of preserving healthy oceans. A sea view is hugely desirable. However, the coastal garden has to contend with blown sand which has the same effect as sandpaper.
A coastal garden also has to cope with salt-laden winds that leave scorch marks and blackened leaf edges on soft-leafed trees and shrubs. Hot dry summers and the direction of the prevailing winds are an added factor.
What are the best tips to develop a coastal garden?
Establish windbreaks of hardy trees and shrubs which will help deflect and lessen the force of wind, stabilise the soil, prevent further erosion of beach and sand dunes and are adapted to salt spray. The coast silver oak (Brachylaena discolor) is fast-growing with leathery, glossy dark leaves with silvery-white undersides.
The coastal camphor bush (Tarchonanthus littoralis) is a quick-growing small tree that tolerates poor soil, salt spray, strong winds and summer drought. The leathery, dark green camphor-scented leaves have a grey underside. Female trees have cream flowers and cotton-wool-like hairy seeds.
The dune crowberry (Searsia crenata), sea guarri (Euclea racemosa), wild olive (Olea europaea subsp. africana), the white milkwood (Sideroxylon inerme) and sand olive (Dodonaea angustifolia) are wind-resistant, good for screening and for stabilising sand dunes. Restios like Cape thatching reed (Elegia tectorum) and Albertinia thatching reed (Thamnochortus insignis) may also be used.
Grasses play an important part in a windy garden, bending in the wind and stabilising the soil. Natal plum (Carissa macrocarpa) has waxy, dark green leaves, thorns, white flowers and red fruit. Tick berry (Osteospermum moniliferum) is a coloniser with yellow flowers. Tolerant of calcareous soils is the wild plum (Harpephyllum caffrum).
Coastal gardens are never immaculate, nor should they be if they are to retain unique character. Natural accessories in the form of driftwood, weathered boulders, smooth pebbles and shells will retain the essence of a garden at the sea.
With climatologists concerned about the winter rainfall, we need to stay committed to conserving water. Lawns that dry out quickly and need frequent watering are not recommended.
Paving squares for paths, and a thick layer of gravel spread over a weed-suppressing membrane as mulch around shrubs, are low maintenance. Establish sheltered places that are protected by pioneer shrubs before attempting to plant more tender subjects.
You need to know whether the soil is alkaline or acidic to know which plants are best suited to your garden. There are different opinions about whether to improve soil. Usually when planting, gardeners incorporate compost and fertiliser, but this can result in soft growth that is damaged by wind. A compromise is to add a small amount of compost when planting, to encourage rooting.
The choice of plants in exposed coastal gardens is limited to those able to withstand deposits from salt-laden spray. Choose local plants that have adapted to these conditions, or plants from similar climates.
Plants that hug the ground are disturbed little by wind and are essential as ground covers as protection from erosion. Trailing arctotis (Arctotis auriculata) and the coastal gazania (Gazania rigens) are fast-growing ground covers that will stabilise soil.
Succulent-leafed vygies interweave and hug the ground, helping prevent soil erosion and retaining moisture in the soil. Suitable grey-leafed shrubs include wild rosemary (Eriocephalus africanus) with white flowers and fluffy seed heads, the salt bush, rhagodia, lavenders and santolina.
Rosemary, upright or spreading, with dark-green, needle-like aromatic foliage and blue flowers is a woody Mediterranean herb for the seaside garden. Sea lavender (Limonium peregrinum) is a local salt-tolerant low shrub with pink papery flowers.
Perez’s sea lavender (Limonium perezii), from the Canary Islands, has long-lasting purple papery flowers and green leathery leaves. Sea holly (Eryngium maritimum) is a dune plant with silvery foliage and prickly thistle-like flowers.
Sea thrift (Armeria maritima) is a compact plant with a rosette of dark green leaves and globes of pink flowers. Some plants, such as agapanthus, cope with wind because of their strong root systems. Colourful perennials include euryops with yellow daisies, felicia with blue daisies, pincushion flowers of coast scabious (Scabiosa incisa) and rusty brown flowers of beach salvia (Salvia aurea).
Additional seasonal colour can come from bulbs and annuals, wild cineraria (Senecio elegans) alyssum, nicotiana and marigold.