A topiary is a closely sheared or clipped shrub that is shaped into an object that would not naturally occur if the shrub was allowed to grow naturally. A topiary can be as simple as a square or ball or as extravagant as the shape of an animal, like a giraffe or elephant. Not all shrubs are suitable for use as a topiary, however. Small-leaved, evergreen shrubs are the best shrubs to use.
Boxwood (Buxus sempervirens) is a drought tolerant shrub that gets its name from the box-shaped leaves present on the young plants. It grows in all types of soil and in every part of the United States if given supplemental moisture. Some boxwood varieties can turn brown or golden when exposed to harsh winter temperatures. The Green Gem, Green Mountain and Green Velvet varieties are more cold tolerant than others. Boxwood is tolerant of partial shade, but growth becomes sparse and unacceptable for a topiary when grown in total shade. All varieties of boxwood can be considered slow-growing.
Yew (Taxus cuspidata) makes a good shrub for a topiary because it does not have the tendency to lose lower leaves as it matures. Yews have long slender leaves that grow thickly around the single or multiple trunks, depending on the variety. Most yew varieties grow into trees if not pruned back to keep them contained. Yews grow in a variety of soils and are drought tolerant once established. They are more shade tolerant than some other shrubs used for a topiary. Yews produce blue berries in the fall that are often eaten by birds. However, all parts of the yew are toxic if consumed.
English Hollies (Ilex aquifolium) have a thick full habit that is appropriate for a topiary. In order to keep the topiary full and healthy, adequate water and fertilization is required. The female holly produces berries in the fall after flowering in the spring. For berry production, a male holly plant must be present so bees can fertilize the female plant. However, attempting to keep the berries on the plant creates a problem when keeping a holly topiary in shape, because you don't want to trim off the berries. A careful pruning program keeps some berries on the plant for display in the fall, while keeping the overall shape of the topiary. Hollies are known for their ability to survive a drastic pruning.