Ground covers are hardy plants that are able to withstand drought after they have established themselves. They tolerate poor soils and grow quickly. Many of them have lax trailing stems that spread by layering. Where the stem touches the ground, it puts down roots, growing into another plant. The problem with ground covers is they can become invasive if not kept in check.
This is the plant you grow if you have large expanses of barren ground to cover quickly. Commonly known as goutweed, this foot-high plant has green and white pointed leaves, slightly toothed at the edges. Patrick Lima, in his book "The Harrowsmith Illustrated Book Of Herbs," warns not to plant it in your garden. Its overly enthusiastic, greedy nature will choke out other plants and soon you will be growing only goutweed. It is hardy in USDA planting zones 2 to 9.
In no time this aggressive vining plant, commonly known as Asian jasmine, forms a dense mat of attractive green leaves, growing 6 to 12 inches high. By midsummer, the plant is smothered in small, white, intensely fragrant flowers, reminiscent of its namesake. Cut the plants back after the flowers have faded so you can enjoy them. It is hardy in USDA planting zones 8 to 10.
Ajuga is another pushy plant that soon grows into a carpet of 4- to 8-inch high, fleshy stems. The glossy foliage comes in shades of purple, blue, copper, red and white. Plant several types together for a show-stopping display. In early spring, the plants put up spikes of blue flowers. Keep Ajuga out of small gardens because it soon takes over. Ajuga is hardy in USDA planting zones 3 to 10.
Although not as fast-growing as some other plants, Thymus serphyllum quickly forms dense mats of trailing green and gray leaves, smothered in pink or white flowers all summer. The plant self-seeds all over the garden and increases by layering. It is useful for planting among stones in a garden path. It soon chokes out weeds and smells lovely when you tread on it. T. serphyllum is hardy in USDA planting zones 2 to 9.