The two types of metal edging most commonly used are aluminum and steel. Another metal used for edging, though used less often, is iron. All three types of metal edging are preferred because they are stronger, more durable and more versatile than other materials such as plastic, wood, concrete and stone.
The aluminum type of metal edging is the most flexible and pliable among the three metals. Some garden owners choose to let their plants grow untamed but still want to have some sense of boundaries for each plant variety. The aluminum type will work best for such garden beds, because the edging can bend and conform easily to frame the irregularly shaped areas. It is also best for elaborate landscaping designs with rounded contours and spherical patterns. Aluminum edging is also the most affordable, making it a top choice for landscape designers who work with large areas of land.
Steel is the strongest type of metal landscape edging, but it is not as flexible. Flower beds that are intentionally grown separately according to color can take advantage of this steel garden edging, because it prevents the flowers from growing out of bounds by creating horizontal boundaries. Steel edging’s ability to form straight lines makes it a preference for gardens and landscape with a modern, trimmed and clean look.
Among the three, iron metal edging is the often least favored, because it is not as flexible as aluminum nor as strong and durable as steel. Iron also tends to rust more quickly and needs to be removed and reinstalled more routinely than the other types. It is also heavier, thus harder and more expensive to transport and install. Garden growers who appreciate an old-world and “rustic” feel to their garden might appreciate the iron’s corrosive characteristics and choose iron as their landscape edging.
Selecting the type of metal edging not only depends on the landscape design but also on the type of soil. A softer variety of soil can easily accommodate flexible edging such as aluminum, but a harder and rocky soil type might call for harder edging, such as steel or iron.
All types of metal edging can pose some danger because of their thin and sharp borders, so most manufacturers produce them with either rolled rims or plastic coatings. The metal sheets can also be painted to prevent rusting and to complement the colors of the outdoors.