Maintenance of Groundcovers
Do not expect instant coverage. The more plants you start with, and the more closely they are spaced, the more quickly they will touch. But ordinarily it takes two years to get the effect of which you dreamed--unless you use annuals, which give results at once but are not permanent. During this early period, while the plants are becoming established, they are not able to fend for themselves. They are dependent on you, and will need weed control and water.
How much you need to feed the plants depends upon your soil and climate. In most areas, after they are established, one feeding a year in early summer is enough. But in sandy soil, plants getting started will need to be fed every two or three weeks, and later be given both a spring and summer feeding.
The belief that groundcovers need absolutely no upkeep is a myth! They need occasional attention, even after they are established. Some should be sheared (perhaps with a mower) or pruned. Watering is often essential, not only to save plants through the dry summers but also to reduce the hazards of fires, since groundcovers collect and hold an under layer of dry leaves. Such areas should be cleaned regularly of trash and paper fragments before they become unsightly.