First grown outdoors by the Romans, topiary is the art of training plants into three-dimensional objects. Topiaries are classified into three general types: pruned, hollow or stuffed.
Pruned topiaries are essentially herbaceous plants or shrubs that are pruned and trained into geometric or whimsical shapes. They are usually supported with a stake when young, which is removed with the plant develops a strong central leader to support itself.
Hollow topiary is fashioned using vining plants that are trained to grow around a wire frame. These frames can either be three-dimensional or occupy a single plane, such as a heart shape made of a single piece of wire.
Stuffed topiaries are made of wire fashioned into the desired shape and stuffed with moss. The plants are planted through the wire frame directly into the moss and held in place with small pins. This type of topiary is usually made from creeping or vining plants.
Used most often to grow hollow and stuffed types of topiary, varieties of true ivy (Hedera helix var.) quickly grow to fill in the topiary frame. They are also easy to train and readily branch out when their growing tips are pinched. Ivy comes in many varieties with varying leaf shapes, colors and variegation.
Creeping fig (Ficus pumila) is a vine-type plant that is ideal for all types of topiary. It has the trademark tri-lobed leaf shape that fig trees do. It does best in full sun outdoors and a south-facing window indoors. It is only hardy in USDA zones 8 through 11, although it temporarily tolerates freezing temperatures.
For an indoor topiary, use the popular vining houseplant wandering Jew (Trandescantia spp.) Its colorful leaves have purple undersides and bi-colored leaf tops that are deep green with a silver center stripe. They are fast-growing and root easily at the nodes, making the wandering Jew ideal to use for hollow or stuffed types of topiary.