Boxwood is one of the most versatile and robust growing evergreens available for planting in my zone. There are a number of great cultivars. Green Velvet matures at 3′ by 3′, and keeps its great color all winter. Green Mountain is virtually identical to Green Velvet, but grows to 4′ tall by 3′ wide. Buxus microphylla koreana, pictured above, is hardy in this full south sun location, and can grow to 5′ by 5′. The winter color is a dull orangy bronze. Winter Gem boxwood is incredibly hardy, and grows slowly to about 4′ by 4′. The leaves are smaller, and narrower than Green Velvet.
There are lots of other hybrids available. Vardar Valley is an outstanding hardy cultivar of buxus sempervirens. It matures at 1′ to 2′. The leaves have a distinctive blue green color. As it is a slow growing variety, it is not routinely offered for sale at local nurseries. Most of the boxwood sold in my area is grown in regions where the season is long enough to permit 2 flushes of growth per season. This means nursery can get a salable product faster. Boxwood is graded by width-not by height. A boxwood takes about 7 years to grow to an 18″-24″ size. This makes them relatively expensive to buy, compared to other ornamental shrubs that grow quickly.
Boxwood is indeed a versatile shrub. They make great hedges, as their growth is uniform, and they are very tolerant of pruning. That tolerance makes them an ideal subject for living sculpture. Boxwood pruned into spheres, squares, cones and cylinders are striking and delightful. The large boxwood in this landscape will be kept pruned in spheres. The small boxwood will be allowed to grow together, and will be pruned flat. This garden will have a much different look in a few years. All of these boxwood are Winter Gem. The fine textured foliage makes them ideal for pruning into a formal, strictly geometric shape. 
Boxwood are quite friendly to other plants. Provided care is taken in the selection of a cultivar for a specific site, they will stay in bounds. These boxwood rectangles are a beautiful foil for the clipped espaliered crab apples. If the face is pruned on a very slight angle out from top to the bottom, they will stay green all the way to the ground. A boxwood which is hard pruned into a specific shape will stay green on the interior.
Boxwood makes a fine tall ground cover under a tree. They are quite shade tolerant. A small landscape such as this is all the more interesting for a change of level. These boxwood are a welcome visual intermediary between the ground plane, and a linden which has grown to substantial size. That they are shade tolerant means they can be sited in lots of places. Naturally grown boxwood make a lovely backdrop for ferns, hostas and shade tolerant perennials. A boxwood provides a green backdrop for the earliest of perennials to appear in the spring. The small texture