An espalier is a tree that is trained flat against a support, such as a fence, with a central vertical stem and several tiers of horizontal branches (arms). It requires careful initial pruning after planting to create the tiers, then annual pruning every summer to keep it in good shape and fruiting well. Espaliers typically have three or four tiers, and reach about 1.8m (6ft) tall and 3–4.5m (10–14¹/₂ft) wide.
 
To create additional espalier tiers, you prune back the main central stem in winter, to stimulate the growth of strong side-shoots. These are trained to form the horizontal arms of the next tier and a new replacement central stem, until the desired number of tiers is reached.
 
Maintaining the shape is a long-term commitment – it’s essential to prune the horizontal tiers every year in late summer. If left unpruned, growth from the arms becomes overly long and more vigorous at the top, eventually reverting to a more natural tree-like form. However, your dedication will be well rewarded, as espaliers make attractive features, are a good use of vertical space, fruit well for many years, and are more compact than free-standing trees.
 
For more on choosing a new tree to train and how to plant and support it, see our guide to starting an espalier. 
 

When to prune espaliers

• When starting new espaliers from scratch or training more tiers on partially pre-trained trees, prune in winter to early spring and again in late summer
• Prune established espaliers every year in late summer when growth slows down
• Carry out renovation pruning on established espaliers when they’re dormant in winter

Pruning after planting in winter to early spring

© RHS/Chris Lane 

1. Plant the single-stemmed tree just in front of the horizontal wires, which should be spaced 35–45cm (14–18in) apart, with the first wire 40cm (16in) from the ground. Attach a bamboo cane vertically to the wires and tie in the stem
2. Prune the stem down to 5–7cm (2–3in) above the first wire, cutting just above a heathy bud. The top bud will produce a replacement central stem, from which the second tier will be trained
3. The lower buds will produce shoots that will form the first tier of branches

Training in the first spring and summer after planting

© RHS/Chris Lane

1. As the new shoot grows from the top bud, tie it in to the vertical bamboo cane, to form a new central stem
2. Select one strong shoot on each side of the main stem to form the first tier. Tie these to bamboo canes attached to the wires at a 40° angle, to promote strong growth. Don’t train them horizontally yet – that would reduce their vigour, as it would curb their apical dominance  
3. In late summer, lower the two selected side-shoots to the horizontal wires, once they’ve stopped growing
4. Prune back all the other side-shoots to two or three leaves

Follow these steps to create more tiers on espaliers you’ve started from scratch or on newly bought, partly pre-trained espaliers. Repeat this process until your espalier has the desired number of horizontal tiers.
 

A typical partially pre-trained espalier sold with two tiers   © RHS / Tim Sandall
 

Pruning in winter or early spring

©RHS / Chris Lane

1. Prune the central vertical stem about 5cm (2in) above the next wire, cutting just above a healthy bud. This top bud will produce a replacement central stem, while the buds below it will sprout new shoots that will form the next tier of branches
2. If the two horizontal branches trained the previous year are growing poorly, prune them back by up to a quarter of their length. Also consider tying them back at 40° in spring to encourage stronger growth by restoring apical dominance  . Lower them back to horizontal in late summer
3. Remove any other side-shoots growing directly from the main stem

Training a new tier in spring and summer

©RHS/Chris Lane
 

1. Tie in the main stem’s new growth to the vertical bamboo cane fixed to the wires
2. Select one strong shoot on each side of the main stem to form the next tier. Tie these to bamboo canes attached to the wires at a 40° angle, to promote strong growth. Don’t train them horizontally yet – that would reduce their vigour, as it would curb their apical dominance     
3. In late summer, lower the two side-shoots to the horizontal wires, once they’ve stopped growing
4. Prune back all the other side-shoots growing from the main stem to three or four leaves
5. Prune all new side-shoots growing from the horizontal branches to three or four leaves beyond the basal cluster (the cluster of up to four leaves at the base of the shoot – see What to look for: 1, in the following section)

Four steps to summer pruning

  © RHS/Chris Lane

1. Once the final tier is formed, entirely remove the new replacement central shoot

2. Cut back the side-shoots growing directly from each of the horizontal branches to three or four leaves above the basal cluster (see What to look for: 2, below)

3. If the side-shoot was pruned in previous years, reduce this year’s growth to one leaf above the basal cluster (see What to look for: 3, below)

4. Remove completely any overly vigorous upright shoots, especially if they originate from the horizontal branches or main stem

What to look for

  © RHS/Chris Lane

1. Basal cluster – this is a cluster of two to four leaves growing closely together at the base of the current season’s growth
2. Side-shoots growing directly from the horizontal branches – these should be pruned to three or four leaves above the basal cluster
3. Side-shoots that have been previously pruned – these should be cut back to one leaf above the basal cluster
4. Terminal bud – once these have formed at the ends of the shoots (from about mid- to late August), growth stops for the year, making it a good time to summer prune espaliers (as well as cordons and stepovers). It’s best to delay pruning until the terminal buds have formed, as the shoots may otherwise produce new growth afterwards, which would require a second round of pruning in September/October, reducing it to one leaf past your previous cut.

Espaliers usually have three or four horizontal branches, but they can be trained with more if you have the skill and patience  ©RHS/Tim Sandall

Thinning out fruiting spurs

Shortening long side-shoots

• In winter, prune up to a third of the over-long shoots back to stubs 3–5cm (1–2in) long, cutting just above a well-placed dormant bud. Take care not to remove more than a third in any one year
• Spread this pruning evenly around the espalier and over several winters
• Follow this pruning by normal summer pruning annually

 
Neglected espaliers

• You may be pruning too early, before growth slows down. Try delaying until September, when larger terminal (end) buds have formed at the shoot tips (see What to look for: 4, in the Summer pruning section above) and the shoots have stopped growing

• If pruning is followed by a spell of good growing conditions (warmth and rain), growth may re-start. Prune back any re-growth in September (or October if pruning later) to one leaf beyond your previous cut

• Try to encourage dormant buds to sprout on the bare part of the main vertical stem using a method known as notching. In late winter/early spring, remove a small crescent-shaped piece of bark just above two or three well positioned dormant buds on the main stem
• Alternatively, select a shoot originating from near the main vertical stem on one of the existing, strong-growing horizontal branches. Train this either as the missing new side branch or as a replacement vertical shoot, depending on which you need. 
  Only two shoots formed after winter pruning. Suitable shoot was selected as a replacement leading shoot   © RHS/Lenka Cooke