Retaining walls support loose soil, sloping hills and other materials and prevent minor landslides. If your garden needs a retaining wall to prevent erosion, try building a simple and inexpensive one yourself. The right design options and sturdy materials will make it strong enough for your needs while remaining affordable.
Timber retaining wall
Pressure-treated pine timbers, like those used for building decking or sheds, work well for an inexpensive retaining wall. The natural look of wood also complements a garden, unlike cement blocks or bricks. Timber may be the least expensive of all retaining wall materials that you can buy, but they do have a few drawbacks. Wood doesn't curve well and splits over time from exposure to sunlight and moisture. A timber retaining wall will only last between 10 and 20 years.
Concrete bag wall
A bag of concrete will set into a hard, stone-like lump inside the bag when exposed to the natural moisture of rainfall. By stacking the bags in a staggered pattern like bricks, an inexpensive garden retaining wall is quickly built. A 36 kg (80 lb) bag of ready-to-use concrete mix costs around £3 as of April 2014. Each bag is much larger than a similarly-priced cement block. Concrete bags also seal together and dry like a mortared brick wall.
Natural stone wall
Natural stone walls can be the most expensive garden retaining walls, unless your property already has the materials you need to build it. Take advantage of any chunks of stone that you may have on the property to build a simple stacked stone wall. Ask your neighbours if they have any unwanted stones as well. If you have to buy stone, cultured stone is a less-expensive alternative that still has a natural look.
Old car tyre wall
It may not be the most attractive material, but old tyres make a very durable and free or inexpensive retaining wall for your garden. Use whole tyres attached with metal posts or wire and filled with compacted dirt or gravel to create a long-lasting retaining wall. Cover the tyres with landscaping timbers, paint or trailing ground-cover plants. Tyres degrade very slowly and will last much longer than wood.