Why an espalier earns its wall space

A sunny wall is the most valuable piece of ground in a British garden, and an espalier is the neatest way to use it. Trained flat against brick or stone, a fruit tree takes up almost no room at ground level, yet crops generously because the wall holds warmth, shelters blossom from late frosts and speeds ripening in a dull summer. Apples such as 'Sunset', 'Egremont Russet' and 'Discovery', and pears like 'Conference' and 'Doyenné du Comice', all respond beautifully to the treatment.

The framework stays low — usually around 1.8 to 2.4 metres — so every branch is within reach. Picking becomes a pleasure rather than a scramble up a ladder. The restricted root run and disciplined pruning also push the tree towards fruit rather than a thicket of leafy shoots, giving you fewer but far finer apples and pears.

Choosing the tree and preparing the wall

Start with the right raw material. A partly trained espalier with two or three tiers already formed saves you two years, though a maiden whip is cheaper and surprisingly quick to shape. For apples choose a moderately vigorous rootstock such as M26 or MM106; for pears, Quince A. Anything on a dwarfing rootstock will struggle to fill the wires.

Fix horizontal wires before planting, spaced about 45 cm apart, with the lowest roughly 45 cm above soil level. Use vine eyes and a turnbuckle so you can tension them properly — slack wire means chafed bark and a wobbly tree.

• Plant 30 to 35 cm out from the wall so air can circulate and the foliage does not scorch.
• Improve the soil with garden compost, but avoid rich, nitrogen-heavy ground.
• Plant bare-root trees between November and March, whenever the ground is workable.

Building the framework, tier by tier

If your tree arrives as a single stem, cut it back in winter to just above the first wire. The following summer, select the two strongest shoots growing sideways and train them along the wire as the first pair of arms; keep the central leader growing upwards. The next winter, shorten the leader to the second wire and repeat the process. In this way you build a ladder of horizontal arms, one pair per wire.

With a part-trained espalier, simply spread the existing arms along their wires and tie them in loosely. Where an arm is shorter than the wire, let it extend; where it overshoots, shorten the tip by about a quarter in winter to keep the shape balanced. Always aim for one clean central stem and evenly matched pairs of arms.

The summer prune that does the real work

This is the ritual that keeps an espalier tidy and productive. From late July to mid-August, shorten the laterals growing from the main arms to three leaves above the basal cluster — the little rosette of leaves at the base of the shoot. Pears are usually pruned a fortnight later than apples, around mid to late August.

Do not cut into older wood at this stage, and leave the leader and extending arms untouched so they can grow on. The purpose is to stop each shoot in its tracks, letting the wood ripen and the fruit buds form along the spurs. Sappy growth left unpruned will simply shade the fruit and harden too late for winter.

Tying in, rubbing out and keeping order

Throughout the growing season, tie shoots to the wires with soft twine or rubber ties, always in a figure of eight so the stem is not strangled. Check ties every month or so; they can bite into a swelling branch surprisingly quickly.

Then be ruthless about unwanted growth:

• Rub out shoots growing straight towards or away from the wall as soon as you spot them.
• Remove anything sprouting below the lowest wire, and any sucker from the rootstock.
• Take out shoots that grow downwards or crowd the spurs in the centre of the tree.
• In winter, thin congested spurs and shorten the previous summer's growth to two or three buds.

Water, feed and the long game

A wall creates a rain shadow, so the ground beneath it dries out faster than you would expect. Water thoroughly in dry spells, especially for the first three years while the roots establish, and mulch with well-rotted manure or compost in spring, keeping it clear of the trunk.

Feed with a potash-rich fertiliser, or a tomato feed, from late spring until midsummer. Avoid high-nitrogen feeds, which produce lush growth and precious little fruit. Expect a light crop in the third or fourth year and a proper one soon after.

Keep an eye out for aphids on young tips, woolly aphid on the bark, and codling moth grubs in the fruit. Net ripening crops against birds, and prune out any sign of canker during a dry spell in summer.

An espalier rewards patience more than any other form of fruit growing. Spend ten minutes a week on tying and rubbing out, a morning in August on the summer prune, and you will have a wall that looks handsome in every season and fills the fruit bowl for decades.