Plan, measure and mark the finished shape of the border with garden twine before purchasing the galvanized metal garden edging.
Dig a trench 1 inch deeper than the width of the edging and 1 inch wider than the edging.
Connect the pieces of edging by laying the strips on the ground and overlapping the notches in the metal.
Cut individual pieces with a skill saw, metal break or hacksaw, and make sections that snugly fill spaces shorter than the precut sections of galvanized metal.
Attach shortened pieces to the longer sections by overlapping the notches in the metal.
Place the galvanized metal garden edging in the trench. Some manufacturers produce an all-in-one edging with support stakes as part of the precast form. Force these stakes into the ground until the bottom of the edging is flush to the bottom of the trench when placing this form of edging.
For edging without built-in stakes, pound supportive aluminum or steel stakes through the notches in the metal into the ground with a hammer or mallet on the planting side of edging. Stakes are essential for the edging to maintain its position.
Install plastic or other material weed barrier between the edging and planting area as an extra weed preventative.
Back fill around the edging with soil. Firmly compress the soil on both sides of subterranean edging. If the soil is packed too loosely, it will settle over time leaving the edging sticking up out of the ground.