Topiary is the art of pruning and clipping woody or semi-woody plants into specific shapes or forms. Standard topiaries are plants that may have multiple trunks in their natural state, but have been pruned to resemble trees, with a single trunk and a rounded canopy of branches. Plants do not have to be large to make successful standards. These specially trained "trees" are often used as decorative accents in formal outdoor landscapes, as well as indoors, and have historically been created from both deciduous and evergreen species.
The Roman naturalist Pliny the Elder described cypress topiary standards and other forms in the first century CE. As with many other art forms, the Romans probably acquired the art of topiary from the Greeks. Though topiary standards were crafted during the Middle Ages, they did not enjoy another vogue until the Renaissance, when standards were topped with canopies shaped like spheres, mushrooms and rings.The use of evergreens in topiary became common in the seventeenth century. Topiary languished during part of the eighteenth century, but was revived in the nineteenth and early twentieth centuries.
Plants to Use
Many different kinds of plants can be trained and clipped into standard form, including flowering species like abutilon or flowering maple; hibiscus; lavatera or tree mallow; and some pelargoniums (geraniums). Ficus or fig trees make excellent subjects, as do sprawling or vining plants like various ivies, coleus and plectranthus. Among evergreens, holly, yew, thuja and laurel are also used in this way.
A rose standard is actually three roses in one---a hardy rootstock, onto which is grafted a cane of a tall rose variety, onto which is grafted a third, more floriferous variety. The flowers and leaves of the top rose provide the rounded crown that characterizes standard topiary plants. Standard roses, sometimes called "tree roses," may need support, and care must be taken to ensure that the crown does not get so big that it topples over. The two grafts also make these roses less cold-hardy than ordinary rose plants.
Herb standards are generally smaller than those created from other types of plants and are frequently used as indoor specimens. Small-leafed herbs like rosemary and lemon verbena, as well as some varieties of lavender, sage and scented geranium, work best. The process of training herbs into standard form is much the same as that described below for larger species. Herb standards are fragrant and decorative, and the clippings can be used for culinary or craft purposes.
Creating a Standard Topiary
To create a standard topiary, choose a plant that has one strong stem or trunk and a dense, leafy growth habit. Prune any subsidiary stems as well as any branches growing from the main stem below the desired crown level. Some smaller plants, like coleus and rosemary, may need staking to help the main trunk stay upright. As the standard grows, continue to eliminate side shoots, but encourage the horizontal growth of branches in the crown until the crown reaches the desired size and shape. Afterwards, clip periodically to maintain the standard form.