Espalier design is an ancient pruning practice that fashions fruit trees, vines or flowering shrubs into artistic, two-dimensional forms. This lateral shaping makes it easier to harvest and mow, maximizes sunlight, and helps trees fit into tight areas.

"It's a great way to utilize growing space next to walls and fences while adding ornamental interest," said Harold Taylor, outdoor landscape manager at Longwood Gardens in Kennett Square, Pennsylvania. "It is also used for efficient use of garden space and as a method for creating outdoor rooms in the landscape."

To espalier (pronounced ess-PAL-yay) a tree is to train it to grow flat against a support of some kind -- a wall, fence or wires, say. Support it with ties or brackets, and prune it to grow sideways by selecting several strong branches from separate levels and eliminating buds shooting toward the front or rear. The horizontal survivors eventually will become the tree's fruiting spurs.

A half-dozen or more classic, architectural espalier profiles have evolved over time. Examples include the "Cordon," with its vertical trunk and multi-tiered horizontal branches; the self-descriptive "Fan," whose branches grow from the trunk at 45 degree angles; the "Candelabra," where vertical branches rise from a single low horizontal limb; and the "Belgian" or "English Fence," where espalier plants are linked in lattice-like fashion to freestanding trellises. The latter often serve as living fences to screen unattractive areas.

"Have patience, as it will take a couple growing seasons or more for your espalier to start taking shape, and five to 10 years until at peak form," said Leonard Perry, a horticulture professor emeritus at University of Vermont Extension, in a fact sheet.

Almost any woody plant can be espaliered, although some, with sturdy yet supple branches, are more genetically suited than others for this training technique.

"Fruit trees are one of the most widely used," Taylor said in an email.

That would include apple and pear trees, along with peaches, pomegranates, figs, cherries, plums, nectarines and apricots.

Ornamental plants with long, flexible branching also make good espalier candidates. Think camellias, holly, magnolia, bougainvillea, climbing roses and a host of others.

Dwarf, semi-dwarf cultivars and young trees that haven't developed thick branching are easier to train than are standard-size, open-canopy varieties. Young trees also are less expensive, while dwarf trees are less likely to outgrow their shape if not pruned every year.

Espalier trees often are used in commercial orchards to boost yields.

"Growing fruit trees as a fruiting wall is becoming common with commercial orchards because it takes less labour to prune and harvest," said Renae Moran, a fruit-growing specialist with University of Maine Cooperative Extension. "However, they do not have the look that a home-trained tree would have since commercial growers do not spend any time fussing with the tree's appearance.

"To a hobby grower, the formal shape of an espalier tree may be the primary reason for choosing the training system," Moran said.

Espalier training usually is done in winter when plants are dormant.

"Once a person overcomes the fear of making pruning mistakes, it's easy," Moran said. "Cleaning up the prunings afterward is more work than the pruning itself."