These places will likely even have ground cover for sale. If a particular ground cover is not available, a garden center would have contacts to other local or regional nurseries that may have a better selection.
Local libraries may also have information on where to buy ground covers.
This information may be in gardening newsletters or magazines. Many companies will advertise in home and garden magazines and offer free catalogs of their selection.
Wherever a gardener decides to buy ground cover, it should be from a source that is credible and trusted.
Ground cover, when handled properly, should be ready to grow and spread immediately after planting.
If ground cover is not treated properly before the sale, it has a good chance of not making it through the first winter.