Training and Pruning Cordons, Espaliers, Dwarf and Bush Apple Trees
Training a cordon
After planting a cordon apple tree no pruning is necessary except for tip-bearing varieties. Shorten the leader of these by a quarter.
Thereafter, all pruning is done in summer by what is known as the modified Lorette system. This is also the most effective method for other restricted forms.
Modified Lorette system
Prune when the new summer growth matures – that is, when the shoots are at least 9 in. (230 mm) long, the leaves are dark and the base is woody.
Cut back shoots from the main stem to three leaves beyond the basal cluster. Prune shoots from existing laterals or spurs to one leaf beyond the basal cluster. Delay pruning laterals less than 9 in. (230 mm) long until they grow to the necessary length.
Sometimes, secondary growth occurs after the summer pruning. In September or early October cut these shoots back to one bud on well-ripened wood.
When a cordon grows beyond the top support wire, untie it and re-fasten it at a more acute angle. Do not lower it to less than 35 degrees from the horizontal.
Lower neighbouring cordons so that they remain parallel.
When the cordon reaches its final height, cut back new growth on the leader to 2 in (12 mm) in May. Cut above a bud and repeat the operation each May.
As the tree gets older, thin overcrowded spurs while dormant during the winter.
Pruning a neglected cordon
Start to improve the shape of the tree in winter, first sawing back some of the thicker vertical branches to within 1-2 in (25-50 mm) of the main stem.
Cut long spurs back according to their thickness — the heaviest ones the hardest. Spread this pruning over two or three years.
During the following summer, prune by the modified Lorette system — removing some of the growth completely.
Training an espalier
A gardener who wants to grow an espalier, but has little pruning experience, should buy a three year-old tree. This will have two tiers, or horizontal branches, already trained by a nursery. Annual pruning is carried out in two stages:
Winter pruning is needed in the early years to produce additional tiers, if required, and to thin overcrowded spurs later.
Summer pruning is the same as for cordons, using the modified Lorette system (see above).
Forming new tiers
After planting and tying the branches to the support wires, cut back the main stem to a bud about 2 in. (50 mm) above the wire that will support the next tier above.
When growth begins select two good buds below the cut, on opposite sides of the stem, to grow into side branches. Rub out any buds between these three.
Tie a cane vertically to the support wires. As the centre shoot grows, tie it to the cane.
Fasten two more canes to the wires on each side of the first cane, setting them at an angle of 45 degrees. Tie the side-shoots to these as they grow.
If one grows more vigorously than the other, lower the angle of the cane and raise the cane of the other to a more vertical position.
In the following winter remove the side canes, lower the branches and tie them to the wire supports.
Repeat this process each year until the desired number of tiers is established. When forming the top tier, cut back the main stem to two side buds, leaving no upper bud.
Do not prune vigorous leaders on the tiers until they have reached the desired length. If growth is weak, however, cut back the previous summer’s growth by a quarter to one-third. Cut in winter to a bud pointing along the support wire.
When the tiers have reached the desired length, cut back the previous year’s growth to a in. (12 mm) in May. Repeat this treatment each May. Otherwise, only summer pruning by the modified Lorette system is necessary.
Training a dwarf pyramid
A dwarf pyramid is trained to a shape similar to that of a Christmas tree.
After planting a two-year-old tree, shorten the central leader to leave about 9 in. (230 mm) of growth made the previous summer. To keep the leader straight, cut back to a bud pointing in the opposite direction from that chosen when the tree was pruned the previous winter.
Shorten branch leaders to about 7 in. (180 mm), cutting back to an outward-pointing bud.
In late July or early August in the south, but later in the north, prune by the modified Lorette system (above). In addition, shorten mature new growth on branch leaders, but not the central leader, to five or six leaves above the basal cluster of leaves.
Each winter, shorten the central leader by the method used at planting time. Restrict the growth of the tree when it has reached a height of about 7 ft (2.1 m) by cutting back by half the previous summer’s growth on the central leader in May.
Each subsequent May shorten the previous summer’s growth to 1/2 in (12 mm). Branch leaders can also be shortened in May if they are crowding a neighbouring tree.
Shaping and pruning a bush apple tree
After planting a two-year-old bush apple tree, shorten branch leaders by about half to two-thirds so that the tips of the branches are roughly level. Prune to an outward-facing bud.
In the following summer a number of lateral shoots will have grown from the branches. In the next winter choose some of these to form more branches. These should all point upwards and outwards.
As a general rule, prune them back to an outward-facing bud. The branches of some varieties, however, have a slightly drooping habit, and these are sometimes best pruned back to an inward-facing bud.
Shorten new growth by one-third if it is vigorous, and by half if it is weaker. After pruning, the tips of the branch leaders should be at least 18 in (455 mm) from their ilea rest neighbour and more or less level with each other.
Laterals not chosen to form ma in branches should be cut back to four buds from the base to form future fruiting spurs. Laterals crowding the centre can either be shortened or removed.
This pruning establishes the basic shape of the tree, although it may be necessary to carry out a little more formative pruning for the next two or three years.
Subsequent pruning of a bush tree depends on whether it is a spur-bearer or a tip-bearer.
A spur-bearer, such as ‘Cox’s Orange Pippin’ or ‘Grenadier’, carries all of the fruit on spurs.
A tip-bearer, such as ‘Worcester Pearmain’ or ‘Bramley’s Seedling’, bears fruit both on spurs and at the tips of shoots — the propor tion differing with each variety.
Pruning a spur-forming bush apple tree
There are many methods of pruning an established spur-forming bush tree, but the easiest for the beginner is what is known as the regulated system. By this method the centre of the tree is kept open by light pruning each winter.
First, cut out dead and diseased wood and either remove shoots that cross or crowd each other, or shorten them so that they no longer cross.
Shorten in the same way any shoots competing with the branch leaders.
In the early years only, shorten branch leaders by cutting away a quarter of the previous season’s growth if the leaders are vigorous, but by only one-third if they are weaker.
The regulated system encourages heavy cropping, but this in turn may cause the size of the fruits to become smaller as the tree gets older. If this happens, cut out some of the fruiting laterals and thin or remove some of the fruiting spurs during the winter.
Pruning a tip-bearing bush apple tree
Tip-bearing apple trees, such as `Bramley’s Seedling’ and `Worcester Pearmain’, produce much of their fruit on the tips of shoots formed in the previous year, and some on spurs. The proportion differs with each variety. Those that are mainly tip-bearing require comparatively little pruning. Prune others by the regulated system.
Every winter, cut back branch leaders to a growth bud to induce lower buds to break and form more tip-bearing shoots. Leave laterals with fruit buds at their tips unpruned, or much potential fruit will be lost.
Where, however, growth is crowded, thin by cutting out some of the previous summer’s growth to three or four buds.
Restoring a neglected tree
An apple tree that has been neglected for some years can sometimes be brought back to fruitfulness by a systematic programme of pruning, fertilising and spraying against pests and diseases.
Neglected trees generally fall into two categories — those that are too vigorous and produce fruit well out of reach, and those that have weak growth and produce only small fruits.
With both kinds of tree, cut out dead and broken wood and treat cankers. Protect all major pruning cuts with tree paint to prevent re-infection.
Pruning an over-vigorous tree
If a tree has grown too tall, cut it back gradually over three or four winters to reduce the shock of severe pruning.
This pruning method, known as `de-horning’, involves cutting out branches to open up the centre of the tree, and reducing the height of others to make fruit-picking easier.
First cut back high branches in the centre to the main trunk.
Prune back outer, tall-growing branches to a lower branch. Lightly thin out smaller laterals and young growth.
When pruning is complete, after three or four years, the main branches should be well spaced out, with the tips at least 2 ft (610 mm) apart horizontally, and 3 ft (1 m) apart vertically.
Space small laterals 18 in. (455 mm) apart, and fruiting spurs 9-12 in. (230-305 mm) apart.
Pruning a weak tree
If a tree has weak growth, the aim is to improve the size of the fruit and to encourage new growth.
In winter, reduce the length of long spur systems. This will cut out some fruit buds, so that those that remain will produce larger fruits.
Cut out the weakest spurs and leave, as far as possible, spurs carrying the plumpest fruit buds.