I was working locally today pruning some pear and apple espalier trees.
What are espalier fruit trees you might well ask?
Espalier Fruit Trees
Espalier fruit trees are a restricted form of fruit growing that trains the trees to grow in a two-dimensional vertical plane. Usually there is some form of post and wire structure built before tree planting to tie the tree to as it grows. This results in a compact two-dimensional tree that in theory is easier to harvest from. In the Irish or UK climate it is a system often used against a south or west facing wall to take advantage of an the warmer, more sheltered microclimate created there, or along a path to take advantage of more regular attention and easier access that the trees will get on a highly frequented walk-way.
Basic Espalier Fruit Tree Advice
My basic advice for people who want espaliers is this: Don’t do it.
Detailed Espalier Fruit Tree Advice
More detailed advice would be: Don’t do it unless you are prepared to invest time and maybe money in understanding the nature of the growth of fruit trees and the time or money in the extra maintenance that fruit growing in unnatural forms involves.
The Natural Shape of Fruit Trees
Most fruit trees grown from seed that are never grafted, pruned or cut will grow to a fairly conical shape and will grow with one trunk called a central leader in orchard terminology – the classic Christmas tree shape is a good example of this form of growth. Such a tree is growing to a natural pattern that doesn’t need human maintenance, as we didn’t interfere in the first place. When we deviate from this – which we do in every fruit tree which is grafted – we are setting up some work for ourselves in re-establishing the natural tree shape. When we want to maintain an unnatural shape as in the case of the popular open-center shape then we are setting up perpetual maintenance work. The more unnatural the shape, the more work involved.
In one way espaliers are an even more unnatural shape again than the open-centre shape, as espaliers are restricted to two dimensions, but in another way they are more natural, as they can be grown to with a central leader, albeit in two dimensions.
Dangerous Ties
I’ve come across many different materials used to tie the branches of espalier trees to a support structures. The list includes bare wire, plastic covered wire, cut-up tights, cable ties and the plastic tying wire found for sale in garden centers. All ties have the potential to wound the tree as it moves or as it outgrows the tie. It is also a disease focal point as the tie may reduce ventilation to some degree. Of these examples I think the cut-up old tights are probably the least harmful being somewhat soft and flexible.
Circular Economy
For tying espaliers, and indeed almost all fruit tree tying, I use old bicycle inner tube cut into appropriately sized strips. They have many advantages being flexible and ultimately degradable (but not biodegradable I think) in the sunshine when stretched, so they will cause less damage than the other options if forgotten about as the tree grows.
Summer Pruning Espalier Fruit Trees in Ireland
I use summer pruning for espaliered trees as I am usually trying to decrease the tree vigour, getting it to exist in a smaller space than would naturally be the case, and to promote fruiting. To read more about the difference between summer and winter pruning you can read my general orchard article here: https://permaculturedesign.ie/orchard-pruning-cork/
The only time I would do any significant winter pruning on an espalier fruit tree is possibly as the first renovation pruning for abandoned espaliers when if there was space, I might convert them into regular central leader trees, as shown in this video:
https://www.youtube.com/watch?v=Svena_EhsKE
If you want to learn about permaculture and orchard care topics then check out my course listings here: https://permaculturedesign.ie/permaculture-courses-2/