A carefully pruned pear tree is trained against a wall...

A carefully pruned pear tree is trained against a wall — a practice called espalier. It also can be done with peach, plum and apple trees, among others. Credit: Chicago Tribune

Fruit trees can take up a lot of space, but you don't need a lot of property to grow them if you take a lesson from the 17th-century French. Because their weather wasn't optimal for growing fruit, gardeners, including those at Louis XVI's Versailles, began training trees to grow flat against a wall or fence.

The two-dimensional trees were protected from cold and wind, soaked up abundant sunlight, and actually produced more fruit than trees left in their natural forms. The technique was named espalier, which is derived from the French word for shoulder, épaule. The method is said to date back even further, to the Middle Ages and even ancient Egypt, but it was the French who popularized and named it, so they're usually credited with developing it.

The technique involves removing unwanted branches and training the rest to grow horizontally by bending and securing them into place. The resulting trees are visually dramatic as well as productive, and they do a nice job of dressing up bare walls and serving as privacy screens. But be forewarned: There's plenty of pruning involved, with faster-growing trees requiring the most maintenance.

Espaliered trees are slower to mature that traditional ones. To speed up the process, young trees can be given a high-nitrogen fertilizer (12-4-8 or 16-4-8) in late April, late June and late August / early September. The feedings will encourage a lot of new growth, so you must be vigilant about clipping new shoots to achieve the desired form. And you shouldn't expect much fruit while you're boosting growth with nitrogen. The goal at the beginning is to achieve size. Fruit comes later.

When your pattern has been established and the tree trained, cut out the last two fertilizer applications and just use a product labeled for fruit trees in spring.. Because espaliered trees are situated up against walls or fences, the lack of air circulation around them can result in an increase in disease and pest problems, so be sure to monitor them closely.

Peach, plum, pear and apple trees lend themselves very nicely to espalier forms, so even if you're short on space, you can reap an abundant harvest - and have a striking landscape sculpture.