Pruning Apple Trees

: Howard Drury; Fact Sheets; 02 April 2022; Hits: 597

Pruning Apples

By Howard Drury

Introduction

During the first four years of a tree's life, the only pruning necessary is to create an initial framework for future years crops. For standards and bushes, this entails severe cutting back of branches to produce open-centred and freely branched trees. Also, any low quality wood must be removed such as dead, weak or diseased shoots. After these initial years, the pruning takes on the maintenance role, producing a regular supply of new fruiting wood, balanced with the need for keeping as much fruiting wood as possible. This is usually less severe than training, although the removal of any dead, diseased wood etc., must continue as a regular maintenance plan. The removal of crossing branches is also necessary and done on a regular basis. All the above pruning will normally take place during winter to encourage the formation of shoot growth, but the pruning of cordons, espaliers and dwarf pyramid trees is done during the summer, to inhibit shoot growth.

If regular, drastic pruning of an established tree is required - this is an indication that the wrong tree has been chosen for the site. Fruit trees are grafted onto a variety of rootstocks to suit all sizes of garden. When selecting new trees, be certain you are buying the right rootstock for the amount of space you have available.

Tip bearers

Many people are confused about the differences between tip and spur bearing apple varieties. It is not at all complicated -tip bearers carry their buds, flowers and fruits according to the season at the tips of the twigs.

Spur bearers

This type of fruit tree carries buds, flowers and fruit on short, twiggy growths off the thinner branches.

Tools of the trade

Pruning Knife

- useful for cleaning up ragged cuts. Also, excellent for removing tiny branches if experienced in handling the saw. This is not used much today now that better saws are available.

Secateurs

- if kept in good state of repair, will cut cleanly for many years. The cut must be made at the centre of the blade, the branches being a maximum of half to three quarters of an inch.

Pruning Saw

- used to prune branches thicker than three quarters of an inch in diameter; i.e. essential for larger branches.

Long handled pruner

- used for stems that are 2-12inches across; often preferred to the use of pruning saw when dealing with larger branches.

How to prune

Make sure the pruning implement is sharp and clean. Jagged, dirty cuts cause disease problems. The cut must be clean, any ragged edges should be trimmed away. Make a sloping cut, with secateurs, a quarter of an inch above an outward sloping bud. The removal of any large branch should be left to the tree surgeon if you doubt your own abilities - and strength! Make a shallow cut on the underside of the branch to be removed - about 4 inches away from the trunk. Then saw downwards to sever the main part of the branch. Saw off the stub close to the trunk leaving the branch collar intact as possible.

Bushes and Standards

Training a 2 year old tree

Prune in winter after planting, keeping 3-5 primary branches. Cut back strong branches to half their length and prune weaker branches to a third of their length. Also remember to remove any snags.

Training a 3 year old tree

Again prune in winter, remove any new growth which closes the heart of the tree and cut back any remaining new growth to half its length if wishing to keep it for the framework. The remaining new growth that is not required for the framework should be cut back to 4 buds.

Pruning an established tree

The simplest way to look after a mature tree is to follow the Regulation System in winter.

Spur Bearing Varieties

: remove dead and badly diseased wood. Cut back crossing branches and vigorous laterals crowding into the centre. Once this is done, leave the leaders alone that are inside the head. Cut back each lateral which that is growing into and beyond the branch leader. All the leaders and laterals outside the head should be left alone. If over-cropping or undersized fruit occur, thin some of the fruiting spurs and cut out some laterals.

Tip Bearing Varieties

: remove dead, diseased and overcrowded wood, followed by cutting back some leaders, leaving alone all the laterals with fruit buds at their tips.

Cordons

A cordon should be trained by tying the main stem to the cane, then remove the tip once it has reached the top wire. This should be carried out in late spring and repeated every year, leaving about 2 inches of new wood. Once a cordon is established, the pruning should take place in mid-July in southern regions, and during early August in other areas. The method used is known as the "Modified Lorette System", and is as follows :- main stem side shoots, once 9 inches long, should be cut above the third leaf beyond the basal cluster. Any lateral side shoots should be cut above the first leaf after the basal cluster.

Espaliers

During spring, tie 3 canes to the wire supports, as in diagram 1. Follow this in summer by training the growth of the terminal bud and two side buds along these canes. Then in early winter remove the two side canes and lower the branches, tying them carefully to the horizontal wires. Repeat this training process until the final number of tiers is obtained.

When pruning an established espalier, the "Modified Lorette System" should be used, as described in pruning a cordon. This should be done during mid-July in the southern regions, and in early August in all other areas, at the same time as thinning out some of the overcrowded spurs where necessary.

Dwarf Pyramids

The dwarf pyramid is a compact, high-yielding tree type if grown in open ground, having a Christmas tree shape and reaching up to 7 feet in height. Unfortunately it is not a popular tree form as it requires regular and careful summer pruning when grown in open ground; but, when pot grown, it is much more appealing. (see "Pruning Apples in Pots" below).

Summer Pruning

Summer pruning checks growth and is necessary for training and maintaining trees grown in restricted form such as the cordon, dwarf pyramid and espalier (see details). It is also useful when unrestricted trees have become too vigorous. It is not recommended for trees that are growing and cropping well, neither should it be practised on trees that are not thriving. Removing foliage in summer checks the root action and shoot growth. It also encourages the development of fruit buds near the base of the pruned shoots. Light and air are admitted to the tree, resulting in well-ripened wood and buds and well coloured fruits.

If you have a tree in need of summer pruning, cut back the laterals of the current season's growth over 12 inches in length and which are woody at the base to within 5 leaves from their point of origin. Do not prune the whole tree all at once. Start in early August and continue until late September. Leaders should not be summer pruned unless it is also intended to restrict their length.

Rejuvenating an old neglected tree

The first question to ask is whether the tree is worth saving. If it is diseased, unsafe or simply too large, it may be better to cut it down, remove the roots and replant with more suitable varieties. If you decide to keep the tree, the rejuvenating programme will need to be spaced over 3 years to avoid shocking the tree too severely. In the first winter remove all dead and diseased branches. Cut out some of the crossing branches. Some of the very tall growths at the centre of the tree can then be cut back. Repeat this procedure during the following 2 winters. In addition, overcrowded secondary branches should be pruned out to create an open-centred tree. Ideally, the main branches should be about 2 feet apart.

Pruning Apples in pots

The dwarf rootstocks M27 and M9 have made it possible to grow fruit trees in pots. Like all container grown plants, careful attention must be paid to drainage, feeding and watering. In winter, protect the roots by wrapping the pots in insulating material or by bringing them indoors until spring. Remember that yields will not be as high as for those trees grown in open ground, and the pot grown apples will have a shorter life than an orchard tree. Plant a 2-year-old tree in the pot and prune the following winter. Cut back the leader to within 6 inches from where it grows from the central trunk. Cut upper branches to 6 ins. from where they arise on the central trunk. Treat lower branches in the same way by leaving them 10 inches long. Remove weak or twisted branches. In subsequent years, prune in the summer. Cut back the leader to a bud on the opposite side of the previous year's direction to keep the tree growing upright. Cut new wood back to 6 ins from where they arise from the last year's wood. Remove weak branches not needed for framework.

Associated Problems

Impatience

- a newly planted tree cannot be expected to produce much fruit in the first couple of seasons. Any blossom appearing in the first few years should be removed; although it will not cause any problems if a single fruit is allowed to develop for tasting purposes. Fruiting normally starts slowly and a high yield of fruit will not be obtained until the tree has reached 4-7 years of age (depending on the variety), and even then it is not guaranteed that a good crop will be borne every following year.

Poor Pruning and Careless Harvesting

- over pruning will result in plenty of new growth the following summer, at the expense of fruiting (depending on the variety). Removing all the tips of laterals spells disaster for tip-bearing varieties, and pulling unripe fruit from the spurs can cause damage and a serious drop in the yield next year.

Over Cropping

- a tree can only support a limited number of large well formed fruit in one season, and thus a heavy crop should be thinned. If this is not done, the resulting fruit will be small and the following year's crop will be very light.

Frost

- a severe frost can be disastrous if occurring when blossom is fully open. The risk can be lessened if a later flowering variety is chosen, especially if your garden is prone to frost. There is no other practical answer to this problem.

Biennial Bearing

- many varieties tend to crop heavily one year and then lightly the following year. However, all varieties will have the same tendencies if not fed, watered or thinned properly. If biennial bearing is a problem, try removing some buds during the spring of the expected heavy cropping season.

Incorrect Siting or Planting

- poor soil conditions and waterlogging cause poor growth, resulting in low yields. There is very little that can be done for an established tree; the problem can be avoided by correct planting techniques.

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