Many of us use synthetic edging: it is a flexible material, easy to cut, natural colored and very cost-effective. However, it is also highly combustible. In the same manner, all types of wood edging are combustible. In Zone 0, within five feet of a house or another structure, we will need to replace them with non-combustible material.
Cor-Ten or weathering steel
If you have to replace combustible edging, have a look at Cor-Ten (strictly speaking COR-TEN ™, often misspelled Corten) steel, also called weathering steel, edging. Cor-Ten steel is a special kind of steel that typically develops a protective layer of rust that stops the oxydation of the material in deeper layers. The thicker the original plate, the longer it will last. Weathering steel generally lasts longer than regular steel:
Weathering steel life cycle—source: cor-ten-steel.com
Weathering steel edging
Weathered Cor-Ten steel edging, from cor-ten-steel.com
Cor-Ten edging is flexible, and can be bent around curves (although there is a limit to its curvature, in the same way as synthetic edging can only bend so much). It is generally purchased in strips (although you can buy it by the foot, and in pre-curved or pre-shaped segments), often 40" per strip. The thickness of the edging is an important aspect of its durability. Cor-Ten can be purchased unweathered, in which case it will need time to develop its characteristic rust-brown color, but it is actually easy to find Cor-Ten edging already weathered, giving you a guaranteed look that will not change. The edging is hammered into the ground with a mallet hitting an intermediate piece of wood over the edging (to minimize marks on the edging), and clips are used to combine two pieces of edging (they can be seen on the above photo).
Because weathering steel edging is very sturdy, it can actually be used as the retaining lip of informal steps in a garden:
Image courtesy of ConcretePaverMolds.com
Example of local use
I use Cor-Ten edging in my garden: I enjoy both the looks and the durability.
Cor-Ten close-up in @Vivi’s garden
Cor-Ten edging: what it looks like in @Vivi’s garden
This is where I purchased my Cor-Ten edging strips: Worth Garden 6 Pack Cor-Ten Steel Landscape Edging w/Rust Patina Finish | Amazon. So far she is happy with them.
More images of Cor-Ten edging on the web:
- Multiple configurations | Edge Right
- Two levels of edging | Roundwood
- The rustic look | Irish Garden Edge
- Decomposed granite stairs | Lawn Edging AU
- Very tall edging (almost a retaining wall) | Alumideas
Please let us know if you are using Cor-Ten edging, or other noncombustible edging materials, and how you like them, by posting in the community—thank you!