A Wind Barrier for KZN Coastal Gardens

How to plant the windbreak: See above sketch (from Zero Energy Project)

• Orient the wind barrier perpendicular to the wind you want to block.

• Begin by planting low-growing groundcovers into the prevailing wind – on the side of the garden from which the wind comes.  Even this ground-level layer will begin to slow down the wind.

• Behind this, add small shrubs (1m and below) and perennials that will begin the process of pushing the upward.

• The next barrier layer consists of medium to large shrubs planted close together to provide a strong structure of support. The wind now also moves through the plant barrier, slowing as it goes.

• Your final layer is a mixed group of trees of varying heights that will once fully grown, provide the barrier at canopy height. Tree trunks and branches are very effective in slowing and re-directing the wind.

• Once the trees provide shade, plant shade-loving shrubs and perennials.

• Don’t forget to include mostly evergreens in order to protect against both summer and winter winds.

Tips:

• Protect new plants with small, temporary wind barriers, like a shade cloth screen; these may be unattractive, but they do help the permanent plants to grow strong and healthy – and faster than without this protection.

• Mulches are essential to prevent moisture loss. Use heavy mulches like wood chips or rough (partially decomposed) compost.

• Consider successional planting: Plant wild grasses and fast-growing between the young trees and shrubs knowing they will die off as the growing plants shade them out. This foliage cover will slow the wind better than a mulch layer, again improving growing conditions.

• Adequate root space is critical for strong root development: Pavements, buildings, driveways, as well as shallow soils, all restrict root development.

Plant characteristics:

Reader, Joy’s, comment that the wind is so strong it strips the Toad tree of all leaves, highlights the importance of correct plant choice:  

• Small leaves:  won’t be shredded by strong winds. Large leaves catch the wind like a parachute, pulling them down and tearing them.

• Plants with flexible stems that move with the wind; plants with rigid, brittle stems and branches easily snap in strong winds.

• Thick, glossy leaves with a waxy layer that protects plants from excessive water loss.

• Leathery leaves too tough to shred that also act as wind deflectors.

• Choose water-wise species. Plants with grey and hairy leaves are protected by the hairs from drying out as the shade and trap moisture. The grey deflects the heat of the sun keeping the plant cool.

Choosing plants:  

Wind as a constant presence in coastal gardens, shouldn’t be underestimated as one of the most limiting factors affecting plant selection.

Trees: Choose trees with even, balanced form and a single leader. Read our article on how to plant and stake trees.

Shrubs: Look for nursery plants with compact growth and multiple stems. Keep pinching out the tips to encourage bushy growth.

Grasses: Grasses are some of the most wind-resistant plants around, and most require little watering. They can even serve as miniature windbreak plantings helping to protect the shrubs and trees in their early growth phase.

Groundcovers: choose compact plants without too much woody growth.

The following are examples of natural groupings: Mimusops caffra, Euclea natalensis, Apodytes dimidiata, Brachylaena discolour, Protorhus longiflora, Acacia (Vachellia) karroo and Sideroxylon inerme. Once grown, add Capparis species, Carissa, and Grewia.

Further inland on hilly slopes one finds Harpephyllum caffrum, Searsia chirindensis, and Protorhus longifolia.

See extensive plant list below the image strip.