Ground covers are a great choice for the yard or garden for many reasons. They can flourish in areas that are hard to maintain, such as slopes, underneath trees, near buildings and overly wet or dry areas. Once established, they don't require much maintenance, although smaller ground covers will need to be weeded. Many have colorful flowers as well as attractive foliage. Their strength is also their weakness, though; many groundcovers spread rapidly and can be considered invasive.
Creeping phlox (Phlox subulata) are especially well suited for spots where little else will grow due to poor soil. Since they do so well under less than ideal conditions, these plants rock the rock garden. Creeping phlox have thick, mossy foliage and lots of small flowers that bloom in the spring. The flowers may be pink, white or purple. Creeping phlox thrive in U.S. Department of Agriculture plant hardiness zones 3b through 9. They need a sunny spot with six hours or more of direct sunlight each day. In the warmer zones they're evergreen, but the foliage will turn brown or die back in cooler climates.
Hosta (Hosta spp.), also known as plantain lily, grows well in the shade. Hostas are hardy in USDA zones 3 through 7 or 8, depending on the type, and there are thousands of types or cultivars from which to choose. The colors of the leaves can be many different shades of green, blue, yellow or a mixture, such as green leaves with yellow or white edges. Their leaves range from less than half a foot to more than a foot in length. The flowers of the hosta can appear in small clusters or on tall stems with multiple blossoms.
Thyme (Thymus spp.) is not only a fragrant, useful herb, it's also a flowering ground cover ideal for rock gardens or filling in a bare spot. Creeping thyme (Thymus serphyllum) has small purple flowers and can cover a 3-foot area. Lemon thyme (Thymus x citriodorus) also has purple flowers and exudes a light lemony scent. Thyme thrives in USDA zones 4 through 9 and needs a sunny spot, preferring six hours or more a day of direct sunlight.
Common periwinkle (Vinca minor) and large periwinkle (Vinca major) usually have purple flowers, although some cultivars have different colors of blossoms. The leaves range from deep green to variegated, with light green leaves and white edges or yellowish leaves with green edges, also depending on the cultivar. The plants' trailing, vine-like stems make them ideal for using in hanging baskets as well as for ground cover. They do well in sun or partial shade. While periwinkle is an attractive plant, it is considered invasive in some areas. If it spreads into forest areas, it can displace the native plants. Common periwinkle is hardy in USDA zones 4 through 8, and large periwinkle is hardy in USDA zones 6b through 9.