Topiary refers to ornamental gardening. In this horticultural practice, the trees, shrubs and bushes are clipped and trimmed to form well defined artificial figures of living beings along with geometric or other shapes. Dense evergreen and woody plants with small leaves or needles that grow compact or columnar are preferred for topiary. As an art form it is a type of living sculpture. It requires a lot a time and patience to practice topiary. However, in modern times, sometimes shaped wire cages are used to guide the growth of plants or shrubs.