Cover crops are plants that are primarily planted not to be harvested for food but for soil erosion control, weed control and improving soil quality while the garden is otherwise dormant. A cover crop is usually ploughed or tilled under before the next food crop is planted, in which cases it is used as a soil amendment and is synonymous with "green manure crop." In its capacity to control weeds it is designated a "living mulch."
From the landscape designer's perspective, the choice between various cover crops could be influenced by aesthetics, since the cover crop is, after all, taking the place of garden plants in between growing seasons. As such, it could be selected with an eye to its aesthetics, in addition to practical considerations. However, when plants are chosen to cover the ground based mainly on aesthetic considerations, they are no longer considered "cover crops." Instead, such plants are classified as groundcovers. Furthermore, while most cover crops are planted with an eye to tilling them into the soil later, groundcovers are not tilled into the soil.