Apple trees cultivation can be adapted to a wide range of growing styles depending on space and individual preference. Here we describe the more classic styles together with some exciting modern innovations which enable a heavy crop of fruit to be grown in the smallest of spaces (our apple trees are grafted onto rootstocks which keep them at an ideal garden size).
These can be grown following instructions for apple trees and are best grown as an ‘open centred’ tree. Crab apples tend to become quite spindly if left to their own devices. To encourage stronger growth we recommend reducing branches by about one third every other year whilst dormant. This has the additional benefit of improving fruit size and health.
Bush Apple Tree
Probably the most widely seen style of apple and, well grown, can be a highly productive method. The aim is to arrive at an open centred apple tree with a maximum of six main branches which form the ‘backbone’ of the tree for life. Sub branches of these will bear most of the fruit and these are removed, allowing replacements to grow, as they reach about four years old.
This will maintain the bulk of the tree in a ‘young’ state to ensure maximum productivity. Bush trees can be planted about 3–3.5m (10–12′) apart. Once planted the central leader (main stem) should be removed at a point just above the highest side branch or feather. This will encourage the feathers to develop and the strongest and best placed ones should be selected as the main frame of the apple tree.
Over the next three seasons all that is needed is to cut these back by about one third in winter to encourage sub branch development. When, from year 4, older sub branches are removed make sure that the cut is made at a union with another as this will maintain a healthy productive branch structure. Aim to limit the height of the tree to around 2.4m (8′). and expect your tree to be yielding up to 22kg (50lb) of fruit once it reaches 5 years of age.
Central Leader Apple Tree
Another very popular and traditional method which gives regular heavy crops and allows plenty of light into the tree. Trees are planted at 2.4m (8′) apart and if more than one row is planted they should be planted alternately with 1.2–1.5m (4–5′) between rows. Each tree needs a centre supporting stake to about 1.8m (6′) high.
Once planted cut back the main stem by about 10–30cm; this allows the rapid development of side branches and these are restricted to a maximum of 10. The most central of these branches becomes the new leader and this is allowed to run up the supporting post to a height of no more than 2.1m (7′). The remaining branches will radiate out from this. Sub branches along the length of these will bear the fruit. To promote better crops in the early years, weigh or tie down these branches to encourage horizontal growth. To keep fruiting wood young and productive the main branches are removed in turn every few years allowing a new replacement to grow.
A 5 year old tree can be expected to produce around 18kg (40lb) of fruit.
Cordon Apple Tree
If space is at a premium the cordon is a very effective system as it utilises ground very efficiently combining close planting distances with a compact style. A framework of 1.8–2.1m (6–7′) posts and horizontal supporting wires is needed. The apple trees are planted against the wire at an angle of 30 degrees along an 2.4m (8′) bamboo cane which is in turn, attached to the wires. Space trees at 45cm (18″) apart. If possible the rows should run north to south with trees pointing north as this will expose the trees to maximum sunlight through the day. As the tree grows it is twisted around the cane which promotes small fruiting branches to break at the point of bend.
Fruiting takes place on the small branches which occur along the length of the main stem. Winter pruning consists of spacing the side branches to about every 23cm (9″) and eventually removing branches that reach 4 years old.
Damaged or misplaced branches are also removed. Summer pruning takes place in mid to late August and is carried out to encourage fruit bud formation for the following year. At this time all new growth is cut back to 2 to 3 buds.
After 5 years, yields of around 7kg (15lb) per apple tree can be expected.
The ‘V’ System
This modern system can be seen on some of the best commercial fruit farms and is an adaptation of the cordon method. Apple trees are planted alternately along a row at an angle of 60 degrees to the ground thus forming a V along the row plant 45cm (18″) apart. The apple trees are supported by a framework of posts and wires (see diagram on next page). The general culture and pruning is as for the cordon. These trees intercept a very high proportion of the available sunlight and the quality of fruit produced is very high. After 5 years yields of 4.5kg (10lb) per tree can be expected. This means that, by investing in a V system around 45kg (100lb) of apples can be picked in a space the size of a 4.5m (15′)row of runner beans!
The ‘S’ System
This style takes advantage of the trees tendency to respond to moderate stress by producing increased yields of fruit and is one of the latest techniques to appear on commercial nurseries. The natural habit of a tree is to grow vertically in response to light and forces of gravity.
If the stem is bent over against these forces the apple tree responds by producing small sub branches at the point of bend. These in turn bear fruit buds the following year.
Trees are planted at an angle of about 30 degrees to the ground across a strong 1.8m (6′) vertical stake to which they are securely fastened. Plant 110cm (3′ 6″) or a little more, apart. In the June of the first two years, when growth is strong and the wood is sappy and flexible, the tree is bent back and then forwards again, ultimately forming an ‘S’ against the stake (see diag).
Pruning needs are relatively light and none is needed until the second year. Thereafter side branches are removed as they age beyond four years to maintain young productive wood. The main stem will be severely retarded by bending and so can be left untouched. After 5 years you can expect a crop of about 9kg (20lb) per tree.
Double u Cordon Trees
These trees have been fashioned using special cultural techniques on the production nursery to give the unique double U form. It is now vital to give the apples tree adequate support after planting. This can be achieved by constructing a frame against which the apple tree can grow or by providing a stake to support each vertical trunk.
These trees are perfect grown against a wall and here support can be provided using trellis or by canes attached to wires. Aftercare however is relatively straightforward as each vertical stem can now be treated as a single cordon. Winter pruning of each vertical should be carried out to ensure lateral branches do not become crowded and to maintain the original form as the tree grows.
Any damaged branches should be removed at this time. Summer pruning is carried out around the last week in June. Here any new growth is cut back to 2 or 3 buds.
The general care of columnar apple trees is the same as other types. These trees are pruned twice a year, in June and again when the tree is dormant during the winter months. In both cases the new growth is cut back to a bud 20cm (8″) from the old wood.