Grapes may be traditional for over arbors, but think outside the vine culture. Hops, that standard ingredient for beer, can work just as well, if not better, to cover an arbor or pergola or to train along a fence. You can even train hops, with support, as a small tree. They're vigorous climbers — great for quick coverage, but you will have to cut them back to keep them under control. The light-green leaves are large and decorative, and the flowers on the female plant are also green and cone-shape with some fragrance.