Maintenance Pruning
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Natural England Technical Information Note TIN017 Traditional orchards: maintenance pruning This information note provides guidance on the reasons for the routine pruning of fruit trees and advice on the different methods used. Other information notes in the series provide guidance on other aspects of traditional orchard management. For an explanation of terms used in this leaflet see the information note TIN021 Orchard glossary. Key points Maintenance pruning Maintenance pruning is necessary to maintain prevents branch rubbing; the balance between fruit production and restricts tree size and maintains a balanced vegetative growth. shape; The timing and amount of pruning required can helps form a strong framework of branches; vary considerably depending on the type of allows air and light into the tree; fruit tree. induces flower and fruit bud formation; and With care it is possible to maintain healthy, stimulates shoot growth to produce young productive fruit trees while still retaining the healthy wood. wildlife value of an orchard. While many complicated pruning techniques What wood to remove have been developed (particularly for apple In the absence of pruning the majority of buds and pear trees), the regular removal of a few that do not remain dormant develop as fruit buds large branches (known as regulated pruning) is and only a few grow as shoots. Therefore, a usually sufficient to maintain tree health and vigorous tree's growth can be checked by vigour. leaving it unpruned or pruning it very lightly for a year. Background Conversely, the harder a shoot or branch is Why trees require maintenance pruning pruned the more vigorously it will grow back. So After approximately ten years of formative hard pruning can stimulate weak growth to pruning, and as the tree matures, the emphasis produce vigorous, non-fruiting vegetative growth. of pruning shifts away from shaping its However, as a consequence less fruit will be vegetative growth and towards fruit production produced. (see TIN016 Traditional orchards: formative pruning of young trees). The general rule for maintaining balance: strongly growing shoots (>25 cm annual The degree, method and timing of pruning varies growth) should be left alone; considerably depending on the species and variety of fruit tree. A healthy tree needs a moderately growing shoots (10-25 cm annual balance between mature fruiting wood and growth) should be pruned lightly; and vegetative growth. Problems can develop when poorly growing shoots (<10 cm annual this balance is not maintained. growth) should be pruned hard. © Natural England 2010 Second edition 19 October 2010 www.naturalengland.org.uk Natural England Technical Information Note TIN017 Traditional orchards: maintenance pruning Pruning will vary both in degree and method, TIN020Traditional orchards: orchards and depending on the age and variety of the tree. wildlife). Older trees require more care when The extent of the pruning will be determined pruning if their wildlife value is to be preserved largely by the growth of the tree, but generally it (see TIN018 Traditional orchards: restoration will be much less severe, and remove a smaller and management of mature and neglected percentage of wood from the tree, than formative orchards). pruning. The condition of the tree and its performance over the previous years are the Forms of fruiting habit in apple best guides for the amount of wood to remove. and pear trees A balanced pruning regime should aim to The basics remove badly placed, weak, overcrowded, Pears and apples have similar fruiting habits and crossing and inward-facing shoots and are often pruned to the same growth forms. It is branches. Pruning will usually be to an outward not necessary to have a detailed knowledge of facing bud to maintain the open structure of the this, but to be able to prune trees successfully it crown. It is best to prune to whatever original is useful to understand the basic principles. style or shape can be seen, bearing in mind the tree's vigour. During its first year of growth a new shoot or lateral produces axillary buds in the leaf axils Drastic pruning to a new shape can over-stress along its length. These buds are revealed when a mature tree. Most traditional orchard trees the leaves fall off in autumn and lie dormant over were pruned originally to either a standard or winter. Hormones within the tree will then half standard open-centred shape (often used determine the destiny of each bud in the for dessert apples and pears) or left with a following spring. central leader forming a main trunk (often used for plums, damsons and cider and perry During the following growing season (ie the varieties). second year of growth) each axillary bud may either: Each tree is individual and should be pruned accordingly, rather than trying to follow remain dormant; instructions to the letter or conform to diagrams develop into a growth bud, extending into leafy in a manual. Different species and even varieties growth; or of the same species of fruit tree have different forms and growth habits which should be taken become a fruit bud, swelling in preparation for into account: pruning will not always follow the flowering the following (third) year. same rules for each tree. Growth buds are slim and pointed and lie close to the bark. Fruit buds become markedly fatter Maintenance pruning and than growth buds and often develop downy bud biodiversity scales. The primary aim of regular maintenance pruning In the third year fruit buds extend into spurs. At is to generate a large, high quality fruit crop. this point the fruit bud usually divides to produce Conflicts with wildlife conservation can arise two or more flowers (and subsequently fruit). when production is the main management goal. Particularly if chemicals are also used. However, This process is repeated year after year so that if care is taken it should be possible to produce a over time these spurs develop into spur good crop without significantly reducing the systems. wildlife value of the orchard. Spur bearers vs. tip bearers Generally the wildlife value of a tree increases Apple trees are divided into spur-bearing as it matures. Older, larger limbs are more likely varieties and tip-bearing varieties, depending to support and develop benign fungi, decaying wood, and rot and bird nesting holes (see Page 2 Natural England Technical Information Note TIN017 Traditional orchards: maintenance pruning upon where along the laterals the axillary buds The following year, as the tip extends into the develop into fruit buds. second season's new growth, the buds immediately below the 'old' tip on the previous Spur bearers year's growth develop into fruit buds. The buds Most apple and virtually all pear varieties are at the base of the shoot remain dormant or form spur bearers. In the second year of growth the vegetative growth (figure 2). Because of this, tip- buds on the tips of each lateral extend into new bearing varieties have a gaunt, less compact vegetative growth, while the buds towards the appearance in comparison to spur-bearers. base develop into fruit buds (figue 1). This leads to the spur systems being distributed fairly evenly along the stems and main branches. These will keep bearing fruit each year, gradually growing longer. Some spur-bearing varieties such as Egremont Russet and Lord Lambourne develop fruit buds on one year old wood, therefore producing flowers and fruit on two-year-old wood. Most varieties only develop fruit buds on two- year old wood and older and so only produce fruit on wood that is at least three years old. These varieties can be pruned using the spur Figure 2 Formation of fruit buds on tip bearers pruning and renewal pruning methods (see below). Tip bearers are unsuitable for restricted forms such as cordons and espaliers where an even distribution of fruit along the main branches is required. Tip bearers should not be spur pruned as this will remove the wood upon which the fruit forms. Care must be taken to leave plenty of short young laterals with fruit buds on the ends. They are best pruned using the renewal or regulated pruning methods. Partial tip bearers Some spur-bearing varieties are also partial tip bearers, producing fruit buds near the tips of one-year old wood in addition to spurs on older Figure 1 Formation of fruit buds on spur bearers wood. These include Bramley's Seedling, Tip bearers Blenheim Orange, Discovery, Epicure and Lord Lambourne. These varieties can be pruned Tip bearers are less common than spur bearers using the spur pruning method, but care must be but include some popular varieties such as taken not to remove too many spurs or fruit Cornish Gillyflower, Irish Peach, Tydeman's buds. Early Worcester and Worcester Pearmain. Basically, they grow in the opposite manner. At the end of the first year’s growth, fruit buds form Methods of pruning standard in clusters near the tip of the shoots, which also apple and pear trees tend to be longer than in spur bearing varieties. Introduction Pruning back to a fruit bud will stop a shoot from putting on any more vegetative growth and force Page 3 Natural England Technical Information Note TIN017 Traditional orchards: maintenance pruning it to expend its energy fruiting. Cutting back to a practice, pruning may involve a combination of dormant or growth bud will encourage one or methods depending on the individual tree. more buds to grow out as new shoots. It will also stimulate any fruit buds further back down the Regulated pruning stem (figure 3). This is the oldest and most basic method of pruning standard trees. It evolved from the ad hoc methods traditionally used in extensive orchards where stock grazed the sward.