Herbs make great edging plants. Low-growing and creeping varieties spill over garden paths with wild abandon, softening edges in the garden. Herbs with upright, shrubby growth habits are perfect plants to edge gravel, brick, or bark walkways, as well as beds and borders. Upright growers include santolina, sage, and lavender. Hedging your beds.
Some herbs make wonderful clippable small hedges, which are especially nice in formal gardens.
Boxwood is a classic hedging plant, but don't overlook the hedging possibilities of santolina, and lavender. Colorize your garden. Variegated leaves add color, texture and depth to a garden. Soliloquies in the garden. Other plants that work well in bed and border corners, or anywhere where a bit of height is needed, are chives and rosemary.