When most people think of groundcovers they think of the low-growing ivy and pachysandra, both of which do fine jobs at covering the ground. But actually, any mass planting that grows together to form a uniform mass planting and effectively covers the soil can be a suitable groundcover. There are no specific rules for height or type of plant that can be a good groundcover.
Some plants work better in shade, others function better on slopes or in long borders. The idea is to look at what you want to cover, the environment that area has, and what will grow in your climate. Groundcovers basic function is to serve as a living mulch to reduce moisture evaporation, control erosion and help prevent compaction of the soil. Therefore you can use a diversity of plants in different parts of your landscape that will create a healthier ecosystem.
Besides shady areas where grass won't grow, there's also the problem of what to do around trees where large roots push up through the ground making it difficult to mow or where trees have been removed and an old stump remains— ground covers work miracles at hiding these problem areas. The one thing that a typical groundcover doesn't do well is stand up to heavy traffic the way a lawn handles traffic. That doesn't mean that you can't walk across a ground cover occasionally, you just don't want to make a habit of doing so.
Groundcovers are extremely popular with many gardeners for the simple reason they're easy to grow and maintain. They don't require regular mowing or fertilizing and most will survive without supplemental watering. Ground covers are basic low maintenance plants.
You want to buy a plant that spreads, but not aggressively. A ground cover that will tolerate a range of soil types that you might have on your property. If the cover outgrows the space you intended for it, the groundcover should be able to be easily removed to keep it inbounds. If your winters are severe, you might want to consider a ground cover that will remain more or less green if it's in a place where you would likely see it during the course of the winter and it might also have berries or seed heads that will provide a visual impression. There are a few minimal requirements for a good groundcover: it should have an interesting shape and pleasing color; need minimal pruning or care; and, hold up for many years with little bother on your part.
Purchase flats of rooted cuttings or individual young plants, or use divisions from existing plants. Before planting, keep the roots evenly moist.
Prepare the site by working in additional organic matter and adding a slow-release fertilizer.
Visually create a grid pattern that will accommodate the spacing requirements for your plant. Dig holes of the appropriate size along this grid so that the plants are equidistant from each other.
Water the transplants well and mulch between them with organic materials. This will keep the the soil evenly moist and help regulate the soil temperature as the plants take root and grow together.
The following is a list of plants that might work for you as a quality groundcover:
Barrenwort: perennial that blooms in spring. Partial shade.
Bishop's weed: spreads readily. Its leaves are plain green or variegated and works well in both sun or shade
Heath: low-growing plants with tiny flower spikes in spring (heath) or fall (heather). Sun or shade.
Bugleweed (ajuga): purple-tinged, green, or variegated leaves with white flowers in the spring.
Cinnamon fern: grows well in shady areas, spreads slowly.
Hostas: foliage plant that has delicate flower spikes in mid to late summer that does well in shade and some variegated varieties can handle some sun.
Irish moss (baby tears): forms a very low cover with a tight mat of tiny, hairy green leaves. Grows well in moist shade areas.
Ivy: the classic groundcover has tough triangular evergreen leaves. Handles both sun and shade.
Wild ginger: neat low patches of patterned leaves. Spreads slowly in shady spots.
Lungwort: likes moist soil in part5ial shade. Comes in a variety of colors and shapes.
Maidenhair fern: spreads slows and grows about 2' tall. Likes shady, cool, moist soil.
Lady's mantle: grows well in sun or partial shade. Has distinctive, ray-green scalloped leaves.
Lily-of-the-valley: spreads evenly in shady areas from tiny bulbs. Leaves die back by late summer.
Pachysandra: another classic groundcover that grows 3" — 9 " with a tiny flower spike in early spring. Remains green throughout the winter. Spreads evenly, likes shade to partial sun.
Prickly pear cactus: thrives in any soil in Zones 6-8
Periwinkle (myrtle): low growing with small, narrowly oval, glossy green leaves year round.
Sedums: succulent leaves on straight 2' stems. Rounded flower heads mature over the growing season and then dry out and remain in place through the winter.
Snow-in-summer: very easy to grow and creeps over sunny sites with poor soil.
Sweet woodruff: weaves a web of fine roots, leaves are topped by delicate, white spring flowers.
Creeping Thyme: low-growing woody, evergreen plants. Tiny lavender-pink flowers in late spring.
Spotted dead nettle: has crinkled, variegated leaves on 6" stems. Likes shade and has tiny lavender flowers if left unsheared