If you start ground covers out according to the soil, light, and water they need, you'll have little maintenance once a healthy growth is established.

Be sure to mulch between plants, especially after initial planting, to help control weeds and to provide a natural, slow-release fertilizer.  A good mulch also protects root systems in the winter, preventing damage.  Use peat moss, sawdust, rotted manure, wood chips, oak leaves, pine needles, straw, or ground corncobs.

Even with a layer of mulch, your ground cover will need weeding once in a while.  Be especially careful to completely remove deep-rooted weeds such as witch grass, or they'll overrun your prized foliage in no time.  Shallow-rooted weeds can be removed by hand after a rain while the soil is moist.

Occasional pruning is a must with most ground covers.  Some are so vigorous, they can choke other plants if not trimmed.  When purchased, plants may be rangy in appearance, so prune them back for thicker growth and more buds.  Plants with long, trailing stems (myrtle, bearberry, ivy, winter creeper) can be cut back halfway with good results.  And woody ground covers benefit from pruning with sharp shears several times a year.

Water ground covers in dry weather.  On steep hills, build ridges to keep water from running downhill too fast.