The majority of fynbos species are adapted to acidic (low ph) soils typical of the mountainous regions of the Western Cape. Gardening with fynbos along the coastal regions therefore requires an understanding of the local environmnet, pressures on the plants and what species are best adapted to these conditions. Coastal gardens are typically characterised by deep sandy soils that are neutral to alkaline (higher ph) and are regularly influenced by strong salt-laden sea winds.
When planning your coastal garden learn from nature and don’t try and create that lush green paradise that you have always dreamed of – it simply wont work. Many gardeners, especially those moving from inland or upcountry, have failed because of preconceived ideas and a lack of understanding of local conditions along the coast. The main considerations when it comes to design and plant selection are soil, wind, aspect and sun/shade.
Soil as mentioned earlier is extremely important. In some coastal areas the rocky acidic soils reach virtually to the coast and you may well be able to grow acid-loving fynbos. Take a look at the soil. Is it deep white-grey sandy soils, much like one would find on the beach or sand sunes. If so then you are limited to alkaline-tolerant species (and the majority of proteas and ericas for example wont work). Whereas if your garden is characterised by being more rocky with grey to brown soils it is likely to be acidic of Table Mountain sandstone origin. A simple PH tester available at most nurseries will help to determine soil pH and in turn which plants are most suitable.
Wind is a big problem, especially in the south western Cape along the coast. In most cases it is not so much the wind but the salt-laden sea air combined with heavy winds that is so damaging to the garden. I have seen some great examples of people cleverly using features of there house (boundary walls or even the house itself) to break the wind, enabling them to plant more wind-sensitive plants. It is also possible to create protected pockets in the garden through the clever planting of hardy, wind-tolerant trees and large shrubs as mother bushes, providing protection for more sensitive species. Good examples of fast growing large shrubs and trees for coastal gardens are Brachylaena discolor (the coastal oak), Tarchonanthus camphoratus (wild camphor), Chrysanthemoides monilifera (bietou), Metalasia muricata (blombos), Rhus lucida (glossy currant, blink taaibos) and Rhus crenata (dune crowb-erry).
The other important consideration is the amount of sun/shade in your coastal garden. This may vary considerably between seasons. By far the majority of fynbos plants are happiest in full sun although there are a few species that are tolerant or even prefer shade. Species that are adapted to coastal conditions and are shade loving include Asparagus densiflorus, Polygala myrtifolia (september bush), Plectranthus madagascariensis, Plectranthus fruticosus and Anemone (Knowltonia) vesicatoria.
Some fynbos bulbs species that do well in coastal soils under shade include Chasmanthe aethiopica (cobralily), Clivia miniata, Lachenalia bulbifera, Lachenalia rubida and Zantedeshia aethiopica (arum lily).
Some of our hardy coastal species that enjoy full sun include Athanasia trifurcata, Chironia baccifera (christmas berry), Cotyledon orbiculata (plakkie, pigs ear), Felecia echinata, Gazania pectinata, Helichrysum dasyanthum, Helichrysum patulum (kooigoed), Lessertia (was Sutherlandia) frutescens, Leonotis leonorus (wild dagga), Metalasia muricata (blombos), Metalasia densa, Muraltia (was Nylandtia) spinosa, Pelargonium betulinum (maagpynbossie), Pelargonium capitatum (coastal malva), Phylica ericoides, Protea obtusifolia (limestone sugarbush), Leucadendron coniferum (dune conebush), Leucadendron meridianum, Leucospermum patersonii (silver-edge pincushion) and Salvia africana-lutea (brown sage).