You can't beat Hostas as a carefree, enduring ground cover for shade, but certain varieties stand out on their own as specimen plants. One of the best is 'Sum and Substance', which forms huge mounds up to 6ft across with deeply veined, chartreuse leaves measuring 9in or more wide by 20in long. The foliage gleams in dappled or morning light and is rarely bothered by slugs or snails. In late summer, lavender flowers appear on 26in scapes. Designated as Hosta of the Year for 2004 by the American Hosta Grower's Association.