January 2016 | The Garden 45

Winter fruit pruning

Fruit-tree pruningApple and pear trees benefit from regular winter pruning so that they continue to bear good quality fruit. Follow this simple approach to create a well-shaped tree and gain a good harvest »Author: Lenka Cooke, RHS Horticultural Advisor, RHS Garden Wisley. Photography: Tim Sandall

Garden solutions

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January 2016 | The Garden 4746 The Garden | January 2016

Winter fruit pruning

Prune branch

leadersShorten by a quarter

to a third, cutting to an outward-facing bud. Prune strong

shoots more lightly.

Inward-facing growth

Remove any vigorous branches growing

towards the centre of the crown. Cut back

close to the main stem.

Downward growthRemove downward growth low on the tree that receives little light. Prune to a more upright branch or remove completely.

Crossing branchesKeep the well-placed, outward-facing branch and remove the crossing branch growing towards the centre of the crown.

On spur bearers remove some of the short fruit spurs where they are crowded

Prune the tips of the main branch leaders but leave side branches (laterals) uncut

Remove vigorous branches that

are crossing or growing into

the canopy

On tip bearers remove some of the older fruited

branches that bend down in

favour of more upright branches

Fruit trees are not only productive, but they can also give structure to a garden while providing shelter, shade and a food source for wildlife. The eye-catching blossom is attractive to pollinating insects and brings welcome colour to a spring garden.

Apple and pear trees will always naturally bear fruit, but annual pruning will improve the shape of the tree, allow better light and air penetration, and encourage growth of younger, more-productive wood to replace the old.

Regular pruning of fruit trees (bush or standard) begins from the time of planting, by creating an open goblet shape with a framework of three to five strong main branches and well-spaced side branches. However, when an inherited fruit tree is more congested, its structure can still be improved by following a few simple rules.

The aim of annual winter pruning is to achieve balance between

growth and fruiting. Often, uncertainty over how to approach pruning ends with mixed results. Little or no pruning will lead to a congested crown of old, less-productive branches bearing lots of small, inferior quality fruit, mostly high on the tree. Overpruning will result in a mass of vigorous, upright growth (watershoots; see p48) and small crops of (albeit) larger fruit.

Traditionally, gardeners needed to know if their fruit were spur-bearing or tip-bearing trees (see below) as they were advised to prune in differ-ent ways. More modern pruning techniques are similar for both, easier to follow and make fewer cuts, while encouraging a balance between a good harvest of fruit and new shoots to support future crops.

Use the right tools for the job to make it easier. Sharpen secateurs and loppers to achieve a neat cut, use a pruning saw when removing larger branches, and a ladder if you need to reach higher stems.

Follow a few simple pruning rules that apply to all apple and pear trees, then tailor the regime to suit the fruiting habit of each tree.

The aim is to create an open goblet-shape tree with well-spaced side branches (laterals). Work evenly through the canopy, and always step back periodically to check that you are not removing too much wood.

✤ Start by removing dead, diseased and damaged wood, cutting back to a healthy branch and taking care not to leave a stub.

✤ Remove vigorous branches that are crossing or growing towards the centre. You can leave thinner shoots, up to a secateur’s length, that are growing towards the middle.

✤ Shorten the previous year’s growth on branch leaders by a quarter to one third.

✤ Remove laterals that are crossing or crowded (spaced closer than 10–15cm / 4–6in at the base). Leave the remaining laterals unpruned.

✤ Remove any downward-growing branches low on the tree, pruning to a more upright branch or back to the main trunk.

On larger, mature trees that have become crowded, lessen congestion in the crown by reducing larger branches, by up to a third. Prune to a strong outward- and upward-facing side branch (with a diameter at least a third of that of the branch being removed). Alternatively, remove branches completely.

Where several branches need to be reduced or removed, spread the work over two or three winters. »

✤ Tip bearers (right) produce fruit buds predominantly at the tips of thin young branches that developed in the previous season.

✤ Spur bearers (below right) produce fruit buds on short sideshoots (spurs) growing from the main branches.

✤ Partial tip bearers produce some spurs carrying fruit buds, and further fruit buds at branch tips.

Traditionally, techniques for pruning made a distinction between these types of trees. The modern approach suggests we can take a more relaxed attitude to most trees – common to all is pruning to open up the canopy for health, and to remove some growth from branch leaders.

However, to ensure ultimate success, there are still a couple of pruning refinements to follow depending on the type of tree:✤ Spur-bearing trees: thin out any congested

spur systems, aiming for a 10–15cm (4–6in) spacing of spurs along the branch.

✤ Tip- or partial tip-bearing trees: cut back some of the older fruited branches to a strong, younger, outward-facing shoot.

Avoid over pruning; should most of the new growth on a spur-bearing tree be shortened, it encourages excessive non-flowering (vegetative) growth. If a tip- or partially tip-bearing tree is given an all-over ‘haircut’ style, a large proportion of potential fruit is removed.

What is the difference between tip and spur?

An inherited tree may not have been pruned regularly or evenly, but with some staged pruning and thinning of branches it can crop well and take on a better shape.

Simple pruning of fruit trees

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48 The Garden | January 2016

Winter fruit pruning

PRUnIng evenTS✤ Thornhayes Nursery, Devon,

20 January, 10am–3pm: Traditional orchard management. See Diary, p79.

✤ RHS Garden Rosemoor, Devon, 21 & 27 January, 11am – 12.30pm: Apple pruning demonstrations; members £13, non-members £23. Call 020 3176 5830 to book. www.rhs.org.uk/rosemoorwhatson

FURTHeR ReADIng✤ RHS Pruning and Training,

by Christopher Brickell and David Joyce, RHS/Dorling Kindersley, 2011, £19.99, isbn 9781405363129.

✤ RHS Vegetable and Fruit Gardening, edited by Michael Pollock, RHS/Dorling Kindersley, 2012, £20, isbn 9781405394420.

Pruning in winter offers the opportunity to also remove material that could potentially spread disease.

Light is needed to penetrate the leaf canopy as fruits ripen and also to promote ripening of young wood that will lead to flower-bud formation, so a crowded canopy of many shoots should be thinned. Congested branches and poor air circulation favour some pests and diseases.

Winter pruning offers an opportunity to remove diseased material and any damaged wood, as this is vulnerable to disease infection. Ensure pruning cuts are neat and made using sharp, clean tools to avoid damage.

Prune out young shoots infected with apple scab or pear scab (it will show as blistering and cracking of the bark).

Damaged bark provides an entry point for apple canker, a fungal disease that may girdle and kill young stems. If possible, remove affected branches where the infected area is often sunken and covered with dead bark showing concentric rings.

To reduce the problems of brown rot and blossom wilt, remove any mummified fruit that tend to stay hanging on the tree – preferably with the piece of branch. When fruit touches the bark, it can transfer the disease and cause further small infections (cankers).

A tree that has been pruned excessively often produces a mass of regrowth in the following year that will itself require pruning.

Hard pruning causes an imbalance in the root and shoot ratio. The root system needs an ‘outlet’ for its energy, and watershoots are produced as a result. Watershoots are strong, unbranched shoots (pictured below) arising from dormant buds in the older wood.

✤ Avoid stimulating any significant watershoot growth by aiming to remove only 10 to 20 percent of the total canopy in any one year.

✤ Remove any watershoots growing on the trunk or the lower parts of the main branches, by cutting them at the base.

✤ Prune out half of the watershoots (at the base of each shoot), to achieve an even spacing and to open up the crown.

✤ Tip-prune the remaining shoots, by removing the top quarter to a third of their length, to encourage these to branch.

✤ In the following year, remove another half of the remaining watershoots. Keep the well-placed shoots and, where they have branched, prune the branch leaders to an outward-facing side branch.

✤ Thin the canopy further in the third year if needed.

Dealing with watershoots

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Science: importance of health, light and air

Use a pruning saw when removing larger branches, cutting close to the main stem (to the branch collar) to avoid leaving a stub.

Apple canker, a fungal disease, can appear as a sunken area of dead bark.

Remove mummified fruit with a portion of branch.

For more advice on pruning apples and pears, search the following on the RHS website.✤ ‘Pruning made easy’: a simple approach✤ ‘Winter pruning apples’: a how-to guide✤ ‘Winter regulated pruning’: to control size✤ ‘Renovating old trees’: for overgrown trees✤ ‘Identifying fruit buds’: tree cropping habits

www.rhs.org.uk

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