Successfully initiating and establishing vegetation into a gabion structure during the construction phase is directly related to the volume of soil placed and sustained within the voids and on the surface of the gabion stone fill.
- Retaining Walls & Vertical Slope Protection:
To ensure that soils are held within the voids of the stone fill for vertical structures we have found that multiple layers of select granular stone placed, swept and water jetted onto the surface and into the gabion stone will fill the voids of the gabion stone and provide a filter to prevent soils from migrating vertically through the gabion structure. It is best to provide a layer of granular stone fill and soil at each 1’ rise of the gabion stone fill.
- Methods for Vegetating Retaining Walls & Vertical Slope Protection
To initiate vegetation take gabion stone fill, soil and seed place each into a rock box then apply small quantity of water and mix the gabion stone fill the soil and the seed together. Once the rock, soil and seed are wet the soil and seed will bond to the stone fill. The result is that when the gabion stone fill is mechanically placed into the gabion structure it will carry soil and seed with it applying soil and seed to the entire cross section of the gabion structure why the layers of granular stone fill provide a filter to prevent soil from migrating vertically.
- Methods for Vegetating Channel Lining & Slope protection:
These structures are generally placed on a slope gradient of 1:5 to 1 or less. Because the slope angles are mild the soil deposited into the voids of the stone fill are much more stable than for vertical protections. Therefore it is typically required to place soil on the surface and apply vegetation through planting or hydro seeding. Another method to vegetate channel linings and slope protections is to place the gabion stone fill then apply 4”- 6” layer of soil then place an erosion control blanket on the surface of the soil and confine all components into the unit by applying the gabion or mattress lid over the top of the erosion control blanket, the soil and the gabion stone fill.
Planting trees and shrubs through a gabion structure is another advantages method for vegetating gabion structures. This requires live stakes typically willow tress be planted through the cross section of the gabion structure through the compacted backfill and be planted into the native slope or soil. This will ensure that the root structure of the trees and shrubs do not affect the gabion structure.
Gabions are unique in that they may be installed to ensure that existing vegetation is not disturbed or destroyed. Construction methods in the field allow for any gabion structure to be installed in harmony with existing vegetation.