Topiaries are among the oldest types of living sculpture, reports Cornell University's horticulture website. Topiary is the practice of growing dense plants and forming them through pruning or training them along a wire frame. The earliest references to topiary art are from 23 to 79 A.D. Topiary sculptures were favoured during the times of ancient Rome, the Italian Renaissance, the Victorian era and even with the early New World settlement at Williamsburg, Virginia. Since houseplants became popular in the 1950s and 1960s, many people continue to grow topiary sculptures indoors.
Selecting a Plant
Select the plant to use as the first step in creating a spiral topiary structure. Plants suitable for indoor topiaries include the Heart leaf philodendron, Baby's tears, Scented geranium, Bun moss, Rosemary vine, Sweet bay, Purple velvet plant, Wax flower and Grape ivy. Whatever plant you find most appealing must be a vining plant that is dense and leafy that will give way to the pruning and training required.
Creating the Frame
Begin with a heavy clay pot. For smaller topiaries, the University of Nebraska's horticulture website recommends a pot 6 inches in diameter. Straighten a heavy wire coat hanger and form the base of the frame. Bend the wire so that it is the shape of a small "e." The open end of the "e" will rest on the bottom of the pot while the horizontal line across the "e" will go up to form the training stalk. Bend the piece that makes the horizontal line of the "e" at a 90 degree angle, and begin to shape a wide spiral on which to train the plant. If you need to lengthen the frame, use twist ties or waterproof tape to secure the required length of wire.
Training the Plant
After the frame is done, fill the pot with potting soil. Plant the young vining plant next to the stem of the topiary spiral shape. As the plant grows, attach branches to the frame using twist ties or "sleepers," being careful not to tighten too much or it may cut through the stalks. The vine will grow along the wire frame and begin to form a spiral topiary sculpture. Pruning can help to maintain the shape and encourage branching as the plant continues to grow.