Keep in mind that you 'miss' a growing season if you don't get things started. eg. you could start some small clumps of different kinds of groundcover in the back corners to see how well they establish and how you like them. Some things may work well, where others don't work at all.
Some perennials and groundcovers do well started in fall, though, but it depends upon how the weather is through the winter if they will develop nice big roots and jump up big and lusty in spring or not.
Don't know about your area, but in Utah where I've planted two gardens for my daughter, we saved a ton of money buying perennials in October when the nurseries will deeply discount things to reduce their inventory. Places like HD and Lowe's will completely clear out their nursery stock, so keep an eye out for that next fall, too. You can really score on evergreens, perennials, shrubs and small trees.
