10/2022 – How to plant your Terraforce retaining wall
According to Terraforce, detailed planning and competent workmanship are such critical aspects of any segmental retaining wall (SRW) that it is easy to forget one of the most important tasks of such a project: the final landscaping that will transform a bland mass of concrete into a display of colour, scent and texture.
Bring your concrete retaining walls to life!
Acknowledgement and thanks go to Liesl Wasmuth (Real Landscapes) and Cherise Viljeon (Cherish Plants) for the information contained in this article.
Although some contractors may argue that an earth retaining wall does not need to look good (if it is fulfilling the function for which it was built), Terraforce argues that one needs to pay attention to concrete’s aesthetic and environmental impact. According to Terraforce, with a good landscaping company you can transform your concrete block retaining wall into an ecosystem that not only looks good but also provides a habitat for insect and plant life displaced by extensive building.
Download our booklet Terraflora: a guide to planting indigenous plants on your terraforce retaining wall: Terraflora
4 key steps to planting a TERRAFORCE wall
Liesl Wasmuth, in-house designer of Real Landscapes, a national landscaping company, offers the following advice on landscaping a Terraforce retaining wall:
Step 1
Consider the type of product to use. Find one that is inexpensive to create retaining walls, planters, steps or even a raised edging. The block wall should also be easy to fill with a good-quality soil.
Step 2
Decide what type of plant/plants you might want to use. This is determined by the effect you would like to create, the climatic conditions, the position, the colour scheme etc.
Top tip
Exposure to sunlight will determine whether you plant a shade-loving plant or one suitable for full sunlight.
Considerations when choosing a plant
Take the height and size of the wall into consideration. Why? The size of the pockets is often determined by this – steep walls often have exceedingly small planting pockets, as blocks are stacked closely together.
When the wall is steep, blocks are sometimes stacked very tightly and get filled with concrete and gravel, making it impossible to plant. When this happens, if the wall isn’t that high, you can create a planter at the top in which trailing plants may be planted to trail down and cover the wall.
If the wall is very high and the area is fairly big, it should be designed to include planting areas, such as terraces or large pockets in which to plant.
Step 3
Analyse the soil on site to see if it is suitable for your chosen plant species, or importing good-quality topsoil and some compost.
Top tip
It’s a good idea to add a good organic fertiliser into the mix, or drop a few pellets into the hole as you plant.
Step 4
Fill the pockets with the desired mixture and start planting cuttings, seedlings or plants. Start at the top and work your way down.
Popular covers for a retaining wall
While there are unlimited options for landscaping your wall, here are the most common ones:
Plant selection 1: Covering the entire wall
- Ivy (Hedera Algeriensis) is vigorous and will cover a wall in no time. It’s suitable for sun and shade. Monitor this plant, as it will take over the whole garden if not controlled. The solution? Trim unruly arms back regularly.
- Convolvulus Sabatius (morning glory) covers quickly in the right conditions, such as good loamy soil, lots of water and temperate conditions.
- For shady areas, Lamium species or Plectranthus Madagascar is a good option.
Plant selection 2: Minimal water requirement
- Aptenia Cordifolia (indigenous to South Africa) is a tough, trailing succulent type ground cover that grows in any soil and is perfect for coastal conditions. It has a bright cerise-red flower in spring and summer.
- Disphyma is also a succulent type creeper, which covers quickly without much water.
- Othonna capensis is an indigenous – to South Africa – succulent type plant with small grey tubular leaves and small yellow flowers.
- Carpobrotus edulis (sour fig) is an extremely hardy succulent.
Top tip
All plants need some water when being planted and for some time after to establish properly. Once they have established, you can let them survive on their own.
Take note
Several plants indigenous to South Africa are also suitable. Here is a great selection: Arctotis (African daisy), Carissa Macrocarpa, Osteospermum ecklonis (creeping Marguerite) and Plectranthus Neochillus.
Feature options: From minimal to more complex solutions
To create features consider planters, and add some feature plants/objects such as cycads or lardy clay pots. A creative solution would be to develop various levels, with steps and little seating areas. If you have a solid wall, try inter-planting a few species with the same watering requirements to produce a colourful show throughout the year.
Did you know?
You can also plant trees along your wall. Roots from existing trees should be trimmed if they are in the way and root barriers may be installed to avoid damage. When planting trees on top of or in level areas within a wall, use ones with less aggressive root systems such as palms, Acacia Xantophloea, Brachylaena or Rhus Pendulina.
Final requirement – Irrigation
Watering is crucial, and therefore an irrigation system is ideal. Even plants that don’t require much water will still benefit from regular watering and will look better than those without irrigation. If you are not using water-wise species, an irrigation system is a must.
The end-result is a unique wall, and with a little effort and thought, something truly special can be created.
Acknowledgement and thanks go to Liesl Wasmuth (Real Landscapes) and Cherise Viljeon (Cherish Plants) for the information contained in this article.