Plastic strips, 6 inches high and from 8 to 12 feet long, are buried in the ground so only the top 1 or 2 inches show above ground. The strip separates the flowerbed from the grass. Metal fencing forms a decorative edging. Rows of bricks and pavers are a more solid edging. Cement poured so it's flush with the soil level provides an edging that facilitates mowing.
Short flowers such as lobelia, marigolds and alyssum provide a colorful border. Plants that grow higher, such as boxwood, are trimmed to form a sturdier edging. Higher bushes form more of a fence than an edging.
Rocks form an edging that fits in with a woodland garden. A strip of gravel between flowerbeds and the lawn forms a mowing border. Other natural edging solutions include wood poles buried in the ground, railroad ties and a strip of wood chips.