In short, Espalier is the name given to a technique of growing trees into a two dimensional flat plane by grafting, pruning and training.
The espalier technique was developed in Europe in the 16th century to help temperate climate fruit grow in cooler climates, by growing them flat against a sunny wall. Gardening Australia has a great Fact Sheet on Espalier.
Any shrub or bush can be espaliered, but popular species include:
- Citrus (orange, lime, lemon)
You might be surprised, but growing a tree in an espalier fashion is easy to do at home.
Finding the location and setting up is the most challenging part. The tree will need to be grown on some kind of sturdy trellis. If you choose a wall, simply attach some horizontal tensioned wires about 30cm apart, they are going to have to take some weight so ensure they are well secured.
Some kind of clips will be required to hold the branches being trained to the wires, soft spongy plastic ties can be bought at your garden center.
Before you plant your tree, look at it from all angles. It is best to plant it with the most horizontal branches to line up with the wall. The other unwanted branches can be pruned back to keep the tree flat.
It is going to take some care and time to keep your tree under control, especially during the growing season so keep your secateurs handy.
There are a number of different styles of espalier you can try.