PRUNING  PRUNING  PRUNING
This is a necessary but misunderstood activity. I have several books devoted to different theories of pruning, and I have tested these ideas on my orchard and garden trees over many years. I have tried to distil the bare essentials, but it is still a bit of an essay. If you like, just read the golden rules and the summary below. I will take some pictures when the trees are bare this winter and post them.

GOLDEN RULES of pruning-

1) study your tree and think about its needs
2) keep the tree in balance
3) don't overdo it (too little pruning is usually better than too much)
4) don't let a jobbing gardener loose on a beautiful but neglected old tree

PRINCIPLES

As one of my teachers at medical school said "Principles are all". If you understand how the trees grows and fruits, you will know WHY you are pruning and be more likely to get it right. Think about how the tree grows. First there is the main leader or trunk. Then there is the framework or scaffold of branches. From these branches arise laterals, and from the laterals sub-laterals, twigs if you please. From these, and indeed from the medium sized and  smaller branches, arise fruiting spurs. These bear the fruit buds which produce blossom, and hopefully fruit. If  you study a tree, you will see that fruiting buds and spurs normally arise from wood that is at least 2 years old. (in some years, some trees will form fruit buds or even spurs on the current year's wood, but this is the exception to the rule) This is fundamental-if you remove all the young wood by ignorant pruning, it will not mature into fruiting wood. One of the common errors in pruning apple trees is what I call the "pudding basin haircut" where the tree is clipped around to give a smooth outline, like a topiary hedge. This always reduces fruiting, and I find it quite ugly.

THE NORMAL GROWTH OF A LEADER

Let us consider and describe a single leader or lateral over three years, below.

year 1, a slim pencil of straight new extension wood grows from the main trunk or a branch.

year 2 the wood that grew last year develops some lateral spurs which develop fruit buds. From its end, a new 'pencil' similar to last year's growth extends. If you look at a tree, trace back from the tip of the latest extension and you can see a line around the leader where this year's wood begins and last year's ends.

year 3 the wood that grew in year 1 produces its first blossom, and hopefully fruit. The year 2 wood produces fruit spurs and buds which will fruit next year, and the current year's growth extends the leader, another slim pencil of clean new wood as in year 1 above. I will try to put some photos of this on the site later, but best of all have a look at a tree, tracing back from the tips, and work it out for yourself.

year 4 as above, by now the spur systems of the year 1 wood are in their second year of fruiting and are probably getting a bit thick and touching nearby branches, leaders and fruit spurs. In other words, the tree is thickening up. If it hasn't been pruned yet, it will probably need attention now if optimum fruiting is to be maintained.


Obviously the above is a typical and as with all biological systems there is variation, for example in a good growing year, vigorous specimens of certain varieties can produce and ripen fruit buds from the  current year's growth. It is also clear that the above process is limited by available nutrient, water and the effects of pests and diseases. The whole process slows down in a very old tree, which produces almost no new extension growth and has gnarled, ancient fruiting spurs. Again, some trees are more vigorous in old age than others (as the Psalm says "they bring forth fruit even in old age")


THE UNPRUNED TREE


year x  at some stage, obviously the tree will reach its maximum potential size (depending on the variety, rootstock, soils, care, disease, rainfall, nutrient etc etc), and the centre of the tree will fill up with growth, like a hedge. As this happens, less light penetrates into the centre of the tree, so there will be less fruit and it will tend to ripen poorly and be small. Also, less air circulates therefore fungal disease is more likely-fungi prefer damp and dark conditions. The tree will therefore fruit less and be subject to more pests and diseases. This happens in nature and in very old neglected trees. It is not necesarily a disaster, such trees can be very beautiful and can build up their own ecosystem. They just don't fruit so well. The tree for its own sake only needs to reproduce a couple of times in its life to keep the variety alive, so (speaking as if the tree had a mind of it's own) it doesn't mind if it only produces fruit every other year and if that fruit is small and unripe. Again, the big old un-maintained, lichen-covered tree in your garden may provide a home for the birds and a beautiful architectural feature in your garden and give 2 or 3 baskets of apples most years, and if you are happy with this there is no need to do anything except get up a ladder (careful!) once every 3 years and saw out a few diseased post-mature branches to allow a bit of light in and space for a bit of new growth. You however, may well prefer a regular supply of quality fruit in which case you are going to have to manage the tree and regulate its growth to some extent. Thats where pruning comes in.

THE BALANCED TREE

If I had to sum up apple tree pruning in one word I would say BALANCE. In any one year, an apple tree should be making 3 things-new extension growth, fruit buds for next year, and fruit for this year. A young tree should be making more extension growth and little or no fruit (you may have to remove fruit to prioritise growth), while a mature tree will produce more fruit and less extension growth.

So how do you keep a tree in balance? By removing badly placed, crossing/rubbing, grossly asymmetrical, worn out or diseased wood in order to allow room for new growth to replace it. That's about it.

WINTER  PRUNING

Start with a young tree. Formative pruning is done in WINTER. I will assume you are going for the bush (1-2 foot trunk) or half standard tree (3-4 foot trunk) on a semi dwarfing roostock, by far the most sensible and easily managed tree. Tall trees with a long trunk, say 5-6 feet, (big rootstock such as MM111 or 25) between the ground and the branches are called standards and are pretty and 'traditional' but hard to manage as you need to get up a ladder to pick and prune-such trees are better as garden features than fruit production units.

Plant the tree in winter, mulch and water if the first year is dry. Do not allow a newly planted tree to carry any apples in its first year, snip them off. You want a reasonably symmetrical framework of branches coming out, the lowest should be at least 18 inches from the ground. Branches with very upright angles are more likely to break, remove then in the favour of more horizontally inclined branches. Do not allow too many branches to develop, remove those which are too close to others. Look down on the trees from above to get a view of how the branches are distributed, try to achieve symmetry. In the second year, consolidate this work by taking out any badly placed branches, those which cross others, any which overcrowd the centre of the tree. Remember to aim to keep the centre of the tree open to light and air for optimal fruit development.

SUMMER PRUNING

A healthy apple tree in good soil in the absence of severe pest problems or drought is likely to make more growth than it needs, and this must be controlled by maintainence pruning in order to achieve steady cropping. This can be done in summer according to the growth of the tree. Every tree, every year is different. For example, in my orchard this summer (July 2004) I have 2 groups of Egremont Russet, one 12 years old in good soil, the other 6 years old in poorer soil. The trees in better soil have set very little fruit this year and have made an enormous amount of new, thin leaders which are choking up the centre of the tree. I will be removing three quarters of these growths next week, pruning them down to half an inch to balance the tree. However, the younger trees are carrying a reasonable crop of apples and they are making a reasonable amount of extension growth. I won't need to prune them at all this summer, although I will be walking round the orchard with my (frequently cleaned and sharpened) Felco number 8 secateurs and making a few snips here and there, particularly to remove any diseased wood. (NB as of 22 August, the smaller younger Egremonts are on average carrying twice as much fruit as the bigger, older trees. I believe this is because the rootstock and the soil are in better balance, more by 'luck' than planning. Matching rootstock to soil is acknowledged to be one of the most difficult problems in planning an orchard. As a rule, rich soil, weaker stock, poorer soil, bigger stock-but MM106 is a good compromise which rarely lets you down)

The classic book on summer pruning is by the Frenchman Louis Lorette. He put a great deal of theory down in a book that's hard to find and not an easy read, but his approach changed pruning for ever. To get, and ripen, maximum apple and pear crops it is necesary to prune in summer to remove excess wood and leaves to allow more light and air into the tree to get the best crops. This is counter-intuitive but it works.

Take a look at your trees around midsummer, if there is an excess of young growth, remove some of it. Don't tip all the shoots back, leave some, remove others by snipping them down to about half an inch to an inch from their origin (hopefully a fruit spur will form there). Always make such cuts just above where a leaf arises, the bit above the pruning cut will die back to the leaf so if you cut too high you will have some dead wood which should be avoided if possible.

PRUNING TOOLS AND CUTS

I favour the very expensive Felco number 8 secateurs, I have (had, see note) 1,000 trees so I must have the best tools to reduce repetitive strain injury, but you can manage with cheaper tools. Secateurs are of 2 types, blade onto anvil or blade past blade (or block). I prefer the latter as I think they give cleaner cuts while the anvil types tend to crush the wood. I don't think it matters much to the gardener with 2 or 3 trees, any secateurs will do if you keep them clean and sharp. Most will cut wood up to about 8mm thick, you can cut thicker wood by pulling the wood away from the blade as you cut. Place the open secateurs over where the cut is to be made and start squeezing. As you do this, grasp the branch above the secateurs and bend it away from your other hand as you carry on squeezing. This has the effect of stretching the wood fibres as they are facing the blade, and this will make them easier to cut. Try it and you'll se what I mean. If as you do this you rock the secateurs to and fro a bit, you will be able to cut through much thicker wood than is possible without the technique. Don't attempt too much though, I have broken a cheap pair of secateurs trying to go through wood that was too thick. For wood of 2cm or thicker you must have a pruning saw. A very good folding one is made by Sandvik ( now I think known as Bahco), who make very good medium price pruning tools. WATCH IT with these saws! I will put a picture of the scars on my left hand up when I have time, it has been wounded by knife, saw, secateurs and once by a scythe, so remember that if your tools are sharp enough to be fit for purpose, they are sharp enough to hurt you quite badly.

NB note on pruning tools added June 2007, for the last 2 seasons we have only used Japanese made Silky Fox saws to prune our apple trees. Julia and I have one each as we used to fight over it when we only had one! These are expensive but better than anything else we have used and I cannot recommend them too highly, if like us you feel that nothing is too good for your trees and/or are getting aches and pains. The Gomtaro Apple 300mm with graduated teeth is the one to get, it comes in a wooden scabbard. I suggest a short prayer for the safety of your hands before withdrawing the blade, one pull will go right through a 1.5 cm branch leaving a perfectly smooth cut and you only have to touch your skin with this saw's teeth to draw blood. With an orchard to look after, better to pay £40 for a saw or secateurs that are more efficient so your wrists last longer-they can't be replaced. Put Silky Fox into Google and you will find a supplier.

Pruning cuts should be made at the correct angle, usually a slanting angle just above the bud you want growth to come from. Larger cuts e.g. removal of main branches from the trunk, should be painted with tar emulsion such as Arbrex to promote wound healing and keep out disease. Don't cut too close to the main trunk, ideally about 1-2 mm above. Don't leave a stump, it will have no sap supply so will die.

FRUIT THINNING

I have (16th July 2007) just added a new page on fruit thinning but decided to leave this text up as well for a bit of compare and contrast. fruit thinning page with photos

Some apple trees (for example Winter King, Miller's Seedling, Spartan) routinely set too much fruit. How much is too much? When there are more apples than the tree can carry to a decent size. Winter King (aka Winston) usually sets about 5 apples to a bunch, If they are all left, you will get 5 apples a bunch all the size of golf balls. This is no use to anyone, so they must be thinned, the operation is best done about a week after blossom has fallen, but can be done May through June. Use scissors or thin bladed topiary secateurs to remove the centre fruit (also known as the king fruit, this often has a short or deformed stalk and is undesireable) and 2 others to leave 2 fruits to the cluster. This can be done with a single snip using a thin sharp tool. If the tree is carrying a heavy crop, it might be wiser to thin most bunches to a single fruit-again, BALANCE, eye the tree over and make a judgement, your experience over a few years will tell you what is right.  In a drought year you might need to thin harder than normal unless you can irrigate.

Another thing about fruit thinning is to do with formative pruning and the shape of the tree. If you have a main branch on a young tree, where the branch has not yet become really solid, apples at the end of the branch will pull it down to a lower position, in which it will set. If this results in a high angled branch being pulled down to the horizontal, great. If however a horizontal branch is pulled down to the floor, not so great. This may be acceptable depending of your view of the aesthetics of the tree, but if you are trying to mow underneath the tree it is a bad thing to have branches trailing on the ground. I therefore remove apples from the end of branches of new growing laterals in order to allow the branch to set at a higher angle. This seems wasteful, but it is not worth gaining a couple more apples this year at the expense of having to remove a whole branch in next winter's pruning because the branch has set in an unacceptably low position. Of course if you have time and energy you can 'maypole' i.e. put in a tall stake and support laden branches with strings. That way you get the good branch angles and also the current year's fruit.

A final word on thinning apples. If this job is neglected when it needs to be done, the result will be more apples, but smaller. I have learned from marketing that it is far better to have 1kilo of good apples than 3 kilos of bad ones (very small apples don't sell well, although we do a roaring trade in 20p bags of 4 or 5 baby apples for children). On top of this, since it costs the tree a lot in nutrients to produce all the pips (pips are protein-dense unlike the flesh which is mainly sugar and water), 400 apples weighing 20 kilos will wear out the tree much more than 150 apples weighing the same 20 kilos. The unthinned tree is therefore more likely to develop biennial fruiting (loads of fruit one year, none the next) which is a bad thing. We have discovered that fruit thinning is essential for many of our apples and few if any of the books I have read stress this enough. I suspect that some of the old varieties, like Winter King (Winston) for example which is a REALLY good apple (great flavour, very crisp, long keeper, extremely reliable, good colour), are not grown any more because of the need to manually thin the fruit every year. This is labour intensive so the industry doesn't want to know. Its quite a pleasant job of you don't have too many trees to do, but don't cut yourself. AS you work, the right hand is snipping away whicle hte left hand often holds the bunch of fruits to place them correctly. I once sliced the tip of my left ring finger open down to the bone, it still doesn't feel right 2 years later.


STRIPPED DOWN SUMMARY OF PRUNING

1) Get the shape of the tree right in the early years by removing asymmetrical or badly placed wood by winter pruning.
2) Remove deformed, overlapping and diseased branches
3) Thin out excessive summer growth (late June-July)
4) Paint over large pruning wounds e.g with Arbrex (careful, it doesn't come out of clothes!)
5) Allow light and air into the centre of the tree
6) Keep your tools sharp, but...
7) ...Don't cut yourself!
8) Favour horizontal branches, avoid sharp upright angles as these tend to break under the weight of a good crop
9) Thin fruit appropriately to avoid excess numbers of small apples
10) If in doubt, just saw out a quarter of the oldest branches every second or third year and leave the rest of the tree alone

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