Using vegetation in conjunction with gabions can improve the transition / soil interface between back or infill materials and the parent material at the cut face. Vegetation placed through or into the gabions (either in the form of live stakes or nursery supplied plants with mature root stock) set root and in this way bond the material present at the cut face. A further advantage is that the vegetation enhances the visual appearance of the gabion face as it grows.

The insert, figure 1, indicates vegetation used being Willow or Poplar. In order to have minimal impact on the environment indigenous species of vegetation should be used. Consideration must be given to local conditions and ecology. Within South Africa, in instances where vegetation species exotic to South Africa are intended to be used, consideration should be given to the category of exotic species as some species are considered as aggressive invasive and thus are prevent from being used by law.

Species that root easily from cuttings are ideal to be used in this application. In circumstances where plants from a nursery that have healthy root stock are being used, the plants can be planted in place as the gabions are being filled and as such become part of the structure.

Further advantages of using vegetation in gabions include:

• As dust and soil fill the voids between the rocks used to pack the gabion, the plants set root, which further bind the rocks together forming a more monolithic system.
• Due to the process of evapo-transpiration, plants further contribute to preventing hydrostatic pressure build-up behind any gabion structures.

The shading effect of vegetation in conjunction with the voids from the rock fill of gabions, contribute to creating microhabitat for various forms of fauna.