Special forms like cones, spirals, and stacked spheres are achieved through careful training and pruning. Herbs like myrtle, rosemary, and lavender are a few plant possibilities. When plants are young, they are carefully grown and pruned until the desired shape is achieved. A stake may be necessary until a strong central leader has developed. The best plant choices often become woody enough to support themselves without any staking.
Hollow topiary utilizes creeping or vining type plants grown around a wire frame.
Common frame shapes include hearts, spheres, pyramids, and animal forms. Simple frames can be constructed out of wire coat hangers or other types of flexible, heavy wire. Ivies are the most common and one of the easiest plants to use for hollow topiaries. Establish the vining plants in a large container, then carefully insert the frame. The vining plants should be loosely attached to the frame.