One idea for your herb border is to use clay pots. If your herb garden is not overly large, you can place similarly sized and colored pots upside down in a row along the outside of your herb garden. Plant herbs that hang, such as creeping thyme or golden oregano, in the pots. Set your clay pots six to 12 inches apart around the outside of the herb garden and fill them with soil. Insert creeping herbs into the pots, and you will have a living, edible border.
Use lavender, rosemary or yarrow as border plants in your herb garden. Lavender is a fragrant herb that produces lavender flowers, rosemary is a culinary herb that feature tiny blue flowers, and yarrow is a medicinal herb that comes in a variety of colors. These perennial herbs grow between two and five feet tall. Cut them back to a foot and a half, so that you can tend to the other herbs in your garden.
Creeping phlox also makes an excellent border plant as it tends to stay close to the ground and provides a pop of color next to the deep greens and yellows of your herbal foliage. It also is fairly compact so it will not spread far into your yard. Creeping phlox comes in a variety of colors from lavender, purple and fuchsia to bright-pink, white and yellow.
If you want a more structured English garden feel to your herb garden use a stone or brick border to accent your herbs. Make sure the stones or bricks are at a height of at least six inches to hold in your herbs, or you can grow your creeping herbs next to the stones so they will crawl over them and dangle down a bit.