Topiary is the practice of creating a sculpture using a variety of techniques. The most basic method uses shearing to create shapes. Topiaries that are more complex can use wire frames to guide plant growth. Creating topiaries is not difficult. You can create small indoor topiaries in small pots to learn the various techniques of making topiary.
Simple freeform topiaries use a single tree or bush--ones grown in pots are often ideal. Yew and juniper trees work well. To make a topiary using freeform techniques, use scissors or pruning shears to create the form--simple geometric shapes like cubes or spheres work best, but shapes like swirling twists are possible.
A shrub topiary uses multiple shrubs and a wire frame to create a shape. To make a shrub topiary, place a wire frame in the location of the topiary. Mark the shrub base. For example, to make a topiary of a four-legged animal, each leg would be a shrub base. Dig holes and plant the shrubs inside the four legs of the wire frame. Train the shrubs up the legs and into the topiary frame. A shrub topiary can take a number of years to fill in the frame.
Sphagnum topiary also uses a wire frame. Unlike shrub topiary, though, sphagnum topiary frames are filled with sphagnum moss. Instead of planting shrubs, plant vines at the base of the topiary and train them to cover the frames. Because vines can bend more easily, they can be trained to more extreme angles than woody shrubs. Because of this, a sphagnum topiary can be more intricate than shrub topiary. Vines tend to grow more quickly than shrubs, so sphagnum topiaries tend to grow in much more quickly than shrub topiary.