Why grow apples as espaliers?

An espalier is simply an apple tree trained flat against a wall or fence, with its branches coaxed into neat horizontal tiers. It is one of the oldest tricks in the British garden, and for good reason. A well-trained espalier takes up almost no depth, fits along a boundary wall or the side of a shed, and can crop heavily for thirty years or more. Because the branches are held open to the sun and air, the fruit ripens evenly and is far easier to pick, thin and net than on a free-standing tree. For anyone gardening on a small plot, or on an allotment where every square metre counts, it is the most productive use of a sunny wall you will find.

Choosing the tree and the right wall

Start with the site. Apples need sun to ripen and to build fruit buds for the following year, so a south- or west-facing wall is ideal. An east-facing wall will work, though the crop will be later and lighter. Avoid north-facing walls and deep shade. Bear in mind that the soil at the foot of any wall is often dry and starved, because the foundations and the wall itself shelter it from rain. Be prepared to water and mulch generously.

Next, the tree. Choose a spur-bearing variety rather than a tip-bearer, because espaliers are pruned by cutting back young shoots — exactly the growth that tip-bearers need to keep for fruiting. Reliable spur-bearing culinary and dessert apples include Discovery, James Grieve, Egremont Russet, Sunset and Fiesta. For rootstock, M26 or MM106 suit most garden soils, while M9 is fine on a small wall with good soil and irrigation. Buy a part-trained tree with two or three tiers already formed if you can; it will save you a full year.

Setting up wires and planting

Fix horizontal galvanised wires across the wall, spaced 35–45cm apart, with the lowest about 45cm above ground level. Use vine eyes or tensioners so the wires stand roughly 5cm clear of the masonry — this gives you room to tie in shoots and lets air circulate behind the foliage. Three or four wires will give you a wall roughly two metres high.

Plant the tree about 30–40cm out from the wall so its roots are clear of the driest zone, at the same depth it was growing in the pot, and stake it firmly. Water it in well. Some growers plant at a slight angle to reduce vigour, but on most garden soils upright planting is perfectly satisfactory. Mulch with well-rotted manure or compost, keeping it clear of the trunk.

Building the tiers: selecting and tying laterals

The vertical stem is your leader, trained straight up the wall. Each season, choose two strong shoots on opposite sides of the leader to form the next tier, and remove everything else. Train these new laterals upwards at 45 degrees at first, using bamboo canes tied to the wires, then gradually lower them towards horizontal over the summer. Bending a branch slows its growth and encourages it to fruit — this is the whole principle behind the espalier.

• Rub out shoots that grow straight out from the wall or back into it.
• Pinch out the growing tip of each lateral once it reaches the spread you want.
• Tie shoots with soft string or rubber ties in a loose figure of eight, never tight enough to strangle the branch.
• Allow roughly 35–45cm between tiers so light reaches the leaves below.

Stop when you reach the top of your wires. A mature espalier will then be maintained rather than extended.

Summer pruning: the secret to a tidy espalier

Summer pruning is what keeps an espalier compact and fruitful, and it is the job most beginners skip. In late July to mid-August, once the lower shoots have begun to firm up, cut back all the current season's laterals to three leaves above the basal cluster — the small rosette of leaves where the shoot joins the branch. This concentrates the tree's energy into forming fruit buds rather than endless wood.

At the same time, shorten any secondary shoots growing from the main laterals, and remove anything crowding the framework. A second, lighter tidy-up in early September helps in a wet year. Follow with a winter prune in January or February, when you can shorten the leader if it has grown too tall and cut out any damaged or misplaced branches.

Feeding, thinning and common pitfalls

Mulch in spring, water thoroughly in dry spells for the first three years, and switch to a high-potash feed from June to encourage fruiting rather than leafy growth. Thin fruitlets in June, leaving one apple per cluster about 10–15cm apart; the fruit will be larger and the tree less likely to exhaust itself. Net against birds as the fruit colours, and watch for woolly aphid and canker.

The usual mistakes are letting laterals rise above horizontal, leaving too many shoots to crowd the wall, and pruning only in winter, which encourages vigorous wood at the expense of fruit. Get the summer pruning right, keep the tiers flat and evenly spaced, and a single wall can quietly supply you with apples for decades.