Shrub topiary entails the pruning (shearing) of live shrubs into decorative shapes, as of animals. It is considered an art form. Not only is the art form, itself called by this name, but the result of such pruning is also known as a "shrub topiary."
What Tools Are Needed to Create a Shrub Topiary?
The artist's work can be simplified by a structure called a "topiary frame." This frame is installed in such a way that, as the shrub grows, it fills in the topiary frame. Branches that breech this framework and stick out through the openings are simply pruned off. So this is an instance where -- as is so often the case in life -- a job can be made a lot easier by having a useful piece of equipment. Guided by the topiary frame, your shearing work to achieve the shape that you want is pretty straightforward -- you are not reduced to having to "eyeball" it (although some people like the challenge of doing just that).
You will also need either a pair of shears (if you prefer to do your trimming manually) or a power hedger (if you are the type that likes to put technology to use) to create a shrub topiary. Many gardeners opt for manual tools to avoid having to listen to the roar of power equipment, but if you have a lot of work to do, there is no doubt that power equipment helps the job go more smoothly. Professionals who maintain large topiary gardens generally make use of power equipment. The figure in the picture was created by the professionals at the Green Animals Topiary Garden in Newport, Rhode Island (United States).
Plants Commonly Used for Topiary
English boxwood is a type of bush commonly used to make certain kinds of shrub topiaries, due to its small leaves, amenability to pruning, its evergreen foliage, and its rounded growth habit. Boxwoods (Buxus) are ideal for creating these shapes. But other kinds of plants are used, as well.
For example, Hetz's Japanese holly (Ilex crenata 'Hetzii') is not far behind boxwood as a natural choice for making topiaries. This shrub, too sports small leaves. In fact, Hetz's Japanese holly is often mistaken for a boxwood, since it is difficult to tell the two apart from a distance. Another good choice for fashioning a topiary is the privet shrub (Ligustrum), which is perhaps better known as an outstanding hedge plant.
But Wait, There's More
But for a full definition of the word, topiary, we must go further, because boxwood shrubs are also often used in another kind of topiary. In this kind, it is not live shrubs that are used, but cut branches. The branches are inserted in styrofoam or in Florist's foam and arranged according to the shape one desires. For instance, at Christmas, "boxwood Christmas trees" are popular -- that is, topiary arrangements in the shape of Christmas trees that are made with sprigs of boxwood. For preservation, these arrangements must be misted often, else they would dry out.