What is an Espalier?
An espalier (pronounced “es-PAL-yer”) is a tree that has been trained to grow in a flat plane against a wall,fence, or trellis, though the term has also been used to describe the technique of training a tree to grow this way.
The technique was invented by the ancient Romans, and further developed in Europe. This technique allowed them to take advantage of the thermal mass of south facing walls (full sun in Northern Hemisphere) by growing fruit trees against them. The heat retained by the walls protected the trees from the cold and extended the productive period of the of fruit trees.
As the technique eventually became an art form in itself, espalier trees became a kind of living sculpture, and many ornamental trees and plants were also used as espaliers.
The main benefit of the technique of growing espaliered trees is that they save a lot of space.
- It’s possible to grow a productive tree in a space that would otherwise be too narrow to be of any use.
- Trellises can be lined up in an open area, a few feet apart, running north to south, so they don’t shade each other, to create a very high density espalier orchard.
- Espaliers can be used to create living fences. A fruit bearing fence fits in with the permaculture principle that “everything has more than one purpose or function” very nicely.
Almost any plant or tree can be grown as an espalier, it’s just a matter of maintaining a two-dimensional form by training all growth along a flat plane, and pruning away any growth that can’t be laid flat because of the direction it’s growing.
Some plants are particularly suitable as espaliers. Plants that produce many flexible lateral branches and attractive flowers, fruit, and foliage and/or bark are excellent choices for espaliers.
How to Build an Espalier Support Against a Wall
The first step to espalier a tree is to construct a support or trellis for it. The following instructions will guide you through constructing an espalier support against a wall, using readily available materials.
If you’re constructing an espalier against a wall, you’ll want a wall that receives full sun at midday.
- In the Northern Hemisphere, this is a south facing wall.
- In the Southern Hemisphere, this is a north facing wall.
As I’m located in the Southern Hemisphere (Australia), I will be using a north facing wall in the example described.
Here is a picture of my espalier support, against the north facing side of a garage wall. The two young pear trees are only just visible against the trellis.
It’s easier to see things more clearly from an overhead angle in the picture below. An espaliered Nashi pear is on the left with two branches, and a Williams pear with four branches on the right. These pears are pollinators for each other, even though the Williams (Bratlett) pear is partially self-fertile). It’s their first year, so they still have some growing to do.
Angle brackets have been used here to hold the support posts away from the wall. The support wires on an espalier trellis should be around 15-20cm (6-8″) away from the wall, to prevent the leaves of the tree getting burnt when the wall heats up to very high temperatures under the full summer sun!
In the picture below the positions of the support wires are highlighted in yellow, to show how the espalier support is constructed.
Star pickets are pre-drilled along their length, so the wires were strung in those holes, approximately 30cm (12″) apart, with the bottom wire around 60cm (24″) above the ground.
Espalier Support Trellis Construction Details
To construct the espalier support, you will need:
- 2.4m (8′) star pickets (x2)
- Heavy duty 15-20cm (6-8″) galvanised right angle brackets (x2)
- Plastic safety caps for ends of star pickets (x2)
- 5mm or 6mm bolts, nuts and washers for fastening bracket to star picket (x2)
- (for brick or concrete wall) masonry anchors of some sort to fasten bracket to wall (x4 or x6)
- 2.0mm or 12 gauge galvanised or plastic coated steel wire (length depends on trellis width and number of support wires – 1 roll)
- turnbuckles (x5)
The diagram below shows how the espalier support is constructed, less the support wires.
Two of these supports need to be constructed, one on either side of the wall, and the wires strung and tensioned between them.
Espalier Support Construction Procedure
- Fasten the brackets to the wall (using masonry anchors if wall is made of brick or concrete) at the same height.
- Line up the star picket the correct distance from the wall so it its holes are facing the wall and align in the same line as the holes in bracket. This is to allow the bracket to be bolted to the star picket.
- Slowly drive the star picket into the ground while keeping it vertical and straight. Aim to drive it around 60cm (2′ or) into the ground, and stop driving it down when a hole in the star picket lines up with the hole in the bracket.
- Bolt the bracket to the star picket, using a nut and washer, or lock washer, so that it doesn’t loosen.
- Fit plastic safety caps at the tops of the star pickets (they form really sharp edges after being hammered in!)
- Wind out turnbuckles to lengthen then, so they can be turned to shorten in length and tighten the wire afterwards.
- String up wires, one at a time, starting at bottom and working upwards. Tie one end of the wire through a hole in the star picket (see details below), and tie the other end to turnbuckle. Attach the turnbuckle to opposite post and turn it to lightly tension the wire.
- When all wires have been strung, tension them all up, from the bottom ones, working upwards.
The most important thing to aim for here is a very sturdy structure. Here are a few important notes:
- Use the heaviest brackets possible, make sure they have the cross-bracing running from one end to the other, forming a closed shape like a triangle. The plain “L” shaped brackets aren’t as strong as these.
- Both the brackets must be mounted sideways, not vertically, with the ends of the brackets facing into the centre of the trellis, and each other. Once the wires are attached and tensioned up, they’ll exert considerable sideways force, pulling the support posts inwards, towards each other. A bracket which runs horizontally is more strongly braced against a horizontal force.
- Use all the holes in the angle brackets to mount them onto the wall. If each bracket has three, use all three. It may be tempting to just put two in, but using all three will be 30% stronger for very little extra effort!
The picture below shows a braced bracket mounted horizontally and facing inwards for maximum support.
The bracket is fastened to the star picket with a single bolt, washer and nut. Since the bolt occupies the hole on the star picket, the wire is fastened around the end of the bracket instead.
The wire is tied to the star picket on one side using a Barrel Roll tie.
On the other side, the wire is attached to a turnbuckle which allows it to be tightened and tensioned.
A turnbuckle with a hook on one end is used to easily attach to the holes in the star picket. In this example, the largest turnbuckles that fit in the star picket holes were used.
The other end of each wire is attached to the eyelet end of the turnbuckle using a Haywire Twist and Barrel Roll tie.
To make a haywire twist and barrel roll tie, follow these five steps:
- Thread the end of the wire through the eyelet of the turnbuckle.
- Cross the end of the wire over itself to form a loop.
- Twist the loop so that both wires twist together three times to make the Haywire Twist.
- Bend the short end or tag out so its sits at 90 degrees to the main wire, like an “L” shape.
- Wrap it three times around the main wire to complete the Barrel Roll.
The turnbuckle hook can’t be attached through the hole in the star picket where the bracket is bolted to it. Tie a small loop of wire securely around the bracket, and hook the turnbuckle to that instead, as shown below.
Do the same, and attach a wire loop for the hole at the top of the star picket that is obscured by the plastic safety cap. Hook the top wire turnbuckle onto the wire look to secure it.
With the espalier support trellis is complete, the tree can be planted (around 30cm (12″) from the wall, and its branches can be trained along the trellis wires.
When training espalier branches, leave the tips pointing upward at a 42 degree angle and gradually tie them to the wire bit by bit as the tip grows. If the branch tip is tied horizontally, the apical (tip) bud stops growing as it no longer releasing plant hormones known as auxins which keep it growing and suppress the buds below it from shooting out new branches.
After a few years the espaliered pear tree pictured above grew to cover the support., as shown below. Note, the piece of wood running across the brick wall close to the top of the espalier is not part of it. That was added later to mount an electric fence for possums, and it stops them eating the espaliered tree!
Please note that there is additional information on setting up support trellises in the article – How to Build a Grape Vine Trellis