At the end of the summer, with beds full of worn out perennials and annuals, sad but resolute gardeners often bid farewell to their color-filled gardens and turn their attention to the fall clean-up. The talk turns to the beautiful autumnal leaves, while inwardly gardeners sulk as they scan the vast expanses of mulch in their formally bountiful flowerbeds. With a little planning and some knowledge of the many magnificent but often less popular plants, gardening can easily become a four season affair.