Fruit trees are trained into particular shapes to make them more productive, easier to manage and better able to support heavy crop loads.
Formative pruning (also referred to as framework pruning) is carried out in the first three years of planting a young tree to create or ‘form’ the shape, and establish a framework of main branches.
When a young tree is first purchased, it may already have some branching, or it may be a ‘whip’ which is basically a long, straight stem with no branches at all. Occasionally a garden nursery will carry out the first year’s pruning to begin establishing a tree shape, either a vase form or a central leader form.
The vase form is the most common tree shape used for most fruit trees, especially in backyard gardens. Being cup-shaped, it has increased branching towards the top, and more space below, allowing for the planting of small shrubs such as berries, taller herbs or companion plants beside the tree. The vase form is universal as it can be used with any fruit tree.
By comparison, the central leader form is the classical ‘Christmas tree’ shape – conical, wider at the base and narrower at the top, with less space below and more space above. Pears, almonds and occasionally apples are grown in this shape.
So, where do we start when looking to select a young fruit tree?
Selecting a Young Fruit Tree
There are three important things to look for when selecting a young fruit tree, as no two trees are alike.
- A nice thick straight trunk (bud-grafted trees will always have a ‘bend’ at the graft junction, that is perfectly normal).
- A good framework of branches (except if the tree is not an unbranched ‘whip’, which is common for fig and mulberry trees).
- An appropriate shape – either a central leader form, a vase form, a flat growing branched shape for espalier training or a whip which can be trained into whatever shape is desired.
Once a tree is selected, it will need to be pruned over a tree year period to establish its shape and form.
The Structure of a Vase Tree Form
The diagram below illustrates the shape of a vase tree form. The trunk is typically between 60cm-1m (2’-3’) tall, with 3-5 main scaffold branches arising from the trunk, which branch further into various levels of sub-branches.
How to Prune a Fruit Tree Whip
When purchasing a young fruit tree from a garden nursery, it may already have branches, but if it’s just a tree ‘whip’, with no branches whatsoever, then it will need to be pruned in winter when it’s dormant to establish new branches.
To get a tree whip to start branching:
- Determine the height of the trunk where the branches will appear, this is typically 60cm-1m (2’-3’) for backyard vase-shaped fruit trees. If growing larger trees that a person can walk under for example, select the appropriate trunk height.
- Find a group of buds at the chosen trunk height.
- Prune above the top bud of the group of buds, make the pruning cut at a 45-degree angle, 6mm (1/4”) above the bud, angled so that water runs away from the bud, and not onto it.
(For more information on making pruning cuts, please see article – How to Prune a Fruit Tree, Step By Step)
Once the tree ‘whip’ is pruned to height, the buds near the top of the whip will shoot to form branches, which can then be pruned to length in the following year next winter.
If left unpruned, a tree ‘whip’ will continue to grow in height and begin branching at whatever height it decides to, which will result in an overly high tree with unreachable fruit!
Once the tree has branches, it possible to commence training the tree into a vase form.
How to Prune a Fruit Tree into a Vase Form in the First Three Years
Training a fruit tree into a vase shape is a three-year process, which is described in detail in the steps below. Formative pruning (framework pruning) is carried out in late winter each year, for the first three years. New growth is pruned back to create further branching.
- In winter, select 3-5 branches to serve as the main branches, remove all others.
- Shorten these branches to a length of approximately 30cm (12”) from the trunk, and prune to an outward-facing or downward facing bud (a bud facing away from the tree trunk). These will form the scaffold branches which will support all other branches.
- Spread the branches to the best positions and angles to form a vase shape. When a tree is first purchased, or when a whip is pruned and grows branches, the branches may be growing straight up or bunched up close to each other.
To achieve the desired 45-60 degree angle from the vertical, the branches can be tied with soft tree-tie material to a timber stake, or a brick, and gently bent into the preferred position.
Plastic branch spreaders are also available for the purpose, they are essentially a short rod with Y-shaped ends, and these can be purchased or home-made.
Once a branch has set into its new position, there will be no more tension on the tree-tie cord, and the branch can then be untied, or bent further. Gently bend branches only, never force them as they may break, ruining the shape of the tree!
- Select 2 or 3 of the stronger outward-growing branches on each of the original scaffold branches to extend the branching framework.
- Prune back all new growth back by half, to an outward-facing bud, making the cut at a 45-degree angle, and 6mm (1/4”) above the outward-facing bud. (For more information on making pruning cuts, please see article – How to Prune a Fruit Tree, Step By Step)
- Remove any branches growing into the centre of the tree to maintain an open vase shape.
- Repeat the Second Year process.
- Continue forming the framework branches over the next few years, as described in the article – How to Prune a Fruit Tree, Step By Step)
After formative pruning has been carried for three years, the tree will be trained into a nice open vase shape, which can then be maintained with what is termed maintenance pruning (detail pruning).
This type of pruning will keep the tree to a manageable size and renew fruiting wood to keep the tree copping consistently.