This article covers pruning old and neglected fruit trees, if you would like to learn how to prune younger or freshly planted trees please read ' An introduction to pruning apple trees'.
I get asked a lot about how to prune older trees, particularly from gardeners who have moved to a new house and have inherited unruly and unproductive specimens. The other common issue is dealing with a older tree that has been pruned too hard either by a previous owner or by the gardener themselves. I hope this article will help avoid pruning problems while also giving some assistance in correcting mistakes that have already been made.
Old and unproductive trees in a commercial orchard would normally be removed (a well pruned new tree will produce far more fruit in the long run) but in the garden there are often other things to consider. You may want to keep an old tree for the beauty it ads to your garden or for sentimental reasons, in this case there is more to consider than just fruit yield.
Reasons for renovating old trees include:
1. To enhance their appearance in the landscape.
2. To restore an old tree with sentimental value.
3. To get better quality fruit.
It is worth bearing in mind that it will take at least 3 years to restore an old tree and in that time you can easily be harvesting quality fruit from a new, healthy semi dwarf tree. It is also not worthwhile trying to save a diseased tree so if the main framework is badly cankered you should remove it and plant a new tree.
Before we get going on tree restoration I am including a list of common pruning terms which should make the following information easier to understand. Don't get overwhelmed on your first read through, it's not as complicated as it sounds!
Common Pruning Terms
Dormant – An tree is in a dormant state in the Winter approx between November and February. At this time the leaves have fallen and the tree’s energy is conserved in the roots, trunk and main branches.
Tip bearing - Fruit is produced on on the tips of the branches. Tip bearing varieties are relatively uncommon. Any pruning of of shoot tips will reduce the yield of a tip bearing tree.
Spur bearing - Fruit is produced on small lateral branches called fruiting spurs. You are more likely to have a spur bearing tree than a tip bearer. You can see a fruiting spur in the photo growing from a small lateral branch.
Partial tip bearers - Many varieties of apple bear fruit on tips and spurs. Partial tip bearers are pruned in the same manner as spur bearers.
Fruiting or flower bud – Fruiting buds (sometimes called flower buds) are larger and more plump than growth buds and have a downy surface. Flower buds produce flowers which mature into fruit.
Wood or Growth bud – Growth buds are smaller than flower buds, they are more pointed and grow flush with the branch.
Outward facing bud – Any growth bud which faces away from the centre of the tree.
Terminal bud – The growth bud at the tip of a branch. Removing the terminal bud will stimulate the buds below to produce woody side shoots which will become new lateral branches.
Spur – Fruiting branches which produce apples, they look like small and stubby compressed stems with fruiting buds.
Leader –The leader is a clear central-leading branch that grows upwards ahead of the other branches.
Scaffold or Lateral branches – Scaffold branches are the main supporting branches of the tree.
Crossing branch – Crossing branches are branches that cross each other creating a dense canopy in the centre of the tree.
Downward branch – A downward branch hangs down from a lateral or scaffold branch, these will never produce fruit and should be removed.
Whorl – A whorl is where three or more small branches originate from the same location, it is common on unpruned mature trees.
Water Sprouts – Water sprouts are thin branches which normally grow straight up from lateral branches.
Suckers – Suckers are unwanted shoots which grow near the base of the trunk. Most apples are grown on grafted rootstocks to control the size of the tree (the immature tree has been joined to a root from a different variety) so the root suckers will not be the same apple as the above ground tree. Suckers also grow faster and stronger than the tree itself and can even out compete it if they are not removed.
Dead Wood – Dead wood is as the name suggests any dead or diseased wood. Dead wood will be obvious when the tree is in leaf due to lack of any leaves but can also be recognised in Winter as it is dark and brittle, often with bark falling away.
Canker - Canker is the most common apple tree disease and is identified by areas of dead, sunken and crusty bark. Canker is highly likely in old and neglected apple trees, the extent of the disease will decide whether the tree is worth saving.
When to prune and how much to prune. Pruning should be completed when the tree is dormant. It is far better to prune a tree just before it comes our of dormancy with early March being ideal. Early winter pruning leaves open wounds exposed to the elements at a time when the tree is unable to repair itself. Pruning when the tree is not in its dormant phase will result in excessive new leafy growth as the expense of fruit production.
The reason restoring an older tree will take 3 years or more is that (a) we don't want to over stress the tree by making too many wounds (remember every cut is an entry point for disease) and (b) we don't want to stimulate vigourous, uncontrolled growth that will severely reduce yield and adversely effect the shape of the tree. I think it is helpful to remember it took more than one season for a tree to become overgrown so it will take more than one season to correct.
The most common mistake is 'topping' shown opposite where excessive pruning has produced a tangle of fast (and weak) growth. This will mean no fruit the following year and a lot of work to restore fruiting for subsequent years. The weak forked joint between fast, new growth and a large limb also leaves the tree more susceptible to storm damage in later years.
THE FOLLOWING IS THE MOST IMPORTANT BIT YOU NEED TO UNDERSTAND: There are two types of cuts you use when pruning a tree; thinning cuts and heading cuts. A thinning cut but means removing complete branches right back to the point where the branch joins the trunk. When renovating an old tree nearly all your cuts will be thinning cuts. A thinning cut allows air and light into a tree and doesn't trigger uncontrolled growth.
A heading cut is used to shape an immature tree. It involves cutting a branch anywhere other than its point of origin and will stimulate growth below the cut. A major heading cut (referred to as 'topping') causes a tree to fight back and quickly try to replace all foliage that has been removed. Heading cuts on main branches produce dense upright growth that congest the tree, block out light and severely hamper fruit production. It will take years to sort out. To understand the effect major heading cuts have on a tree it might help to look at 'apical dominance' as follows:
Apical dominance it the process that allows the tree to grow upright so it can present its leaves to the sun and make energy. Without apical dominance tree growth would be completely random. The leading bud (the last bud at the tip of a branch) produces the hormone auxin that controls the buds below and prevents them producing new branches. If the leading bud is removed (by a heading cut) auxin levels fall and the buds lower down spring into action and produce new lateral branches. Once the leader is gone everyone wants to be king! You can see the result of major heading cuts in the 'NOT GOOD' image below.
The trees environment Before doing any renovation it is a good idea to concentrate on the trees general health. Plenty of light and good airflow will be essential for a good recovery so cut back any hedging or large shrubs that may be causing congestion. In many cases apple trees are planted too close together so you may need to decide on trees to keep and trees to remove altogether. A slow release feed like good garden compost spread around the base of the tree will also aid recovery. Avoid high nitrogen feeds however as they will stimulate too much new growth.
The tools of the trade To prune an old tree you will need am good quality secateurs, loppers and a pruning saw or bow saw. You will need the pruning saw or bow saw more in year one and will be using the secateurs and loppers every year thereafter. To keep a fruit tree in top productive condition it will need a small amount of pruning every year.
My top tip for the day is to get yourself a pack of coloured chalk. I find chalk very helpful for marking the branches I am thinking of removing but also for highlighting the ones I definitely want to keep.
You need to take your time in contemplating the finished shape of your tree and only start cutting with a definite plan in mind. If you are new to this (we all were once) marking the branches will take a lot of the stress and uncertainty out of the job and ensure a cool and calculated result.
Ok, are we ready to start pruning? Here we go......
Year 1 - The first year of pruning is to remove any dead, damaged or diseased wood and to open out the centre of the tree. You should not remove more than 25% of the tree per year or it will try to repair the damage by producing too much new growth. All the cuts you will be making at this stage will be thinning cuts.
First remove any dead wood, it will be obvious from its appearance and lack of buds or new growth. Dead wood is not counted as part of the 25% limit.
Look for damaged wood where two branches have been crossing and rubbing or where branches have come into contact with a neighbouring tree and remove.
Any branches showing signs of canker will need to be taken down. Bear in mind that canker is a fungal disease that can be spread through contact. Even when removing dead wood care should be taken as canker was likely the cause of its demise and may still be present. It is good practice to dip pruning tools in a sterilising solution as you work to avoid spreading the disease.
With an old tree it is better to make a small number of large cuts than a large number of small ones. Neglected trees often have a crowded main branch framework so the objective of pruning is to improve branch spacing, allowing light and air to reach all parts of the tree. The resulting open 'goblet' shape is better for ripening fruit, easy picking and yearly pruning.
It is likely that you will have one or two large branches crowding the center of the tree. This branch (or branches) need to be removed right down to the union with the trunk.
Do not cut flush but just above the 'collar' which is the raised ring where the branch meets the trunk. The cut should be at an angle (often facilitated by the tree anyway) to allow water to run off. If the branch is too large to remove in one go it can be taken down in sections as long as the whole is finally removed. Do not leave partial limbs or stubs, thinning out entire limbs will result in considerably less regrowth. You will be surprised how much difference removing just one large central branch will make in opening up the tree.
Next remove any suckers from the base of the tree, at that stage you are likely to have reached your 25% rule and should leave the tree alone until the following season. This is the point where you will be tempted to do more, don't. This is the point that separates the amateurs from the pro's.
Year 2 - Pruning in the second year will be more concerned with shaping the tree and building on the 'goblet' shape you initiated in year 1. The goal in pruning a tree is to remove congestion. As we've said we are trying to get as much air and light into the tree while also cutting out crossing branches that will rub and be an entry point for disease. As with year 1, the 25% rule still applies.
Spend time at this point contemplating the tree and try to picture the ideal shape to suit your needs. Are the fruiting branches too high up and out of reach? Are there low hanging branches that block access to the tree for picking and pruning? There is an old saying that a tree is well pruned if you can throw your hat through it, keep this in mind as you look at your tree.
Safely removing large lateral branches If you are removing a large lateral branch the method is to make 3 cuts to avoid the branch tearing at the trunk as it falls. Make the first cut below the branch about 6 inches from the trunk, this cut should be about a third of the distance into the branch.
The second cut is made about 3 inches below the first, you may need to cut all the way through but it is likely the branch will snap off when you reach the depth of the first cut.
You will be left with a stump with can now be safely removed from the tree. Cut tight to the branch collar but not completely flush with the trunk of the tree.
Downward facing branches - If you look at the main tree diagram above you will see a number of branches that are growing towards the ground. These restrict access to the tree and are shaded from the branches above so won't fruit well. Remove any downward facing branches cutting back to their point of origin.
Upward growing branches and new sprouts - Remove any branches that grow straight up from any of your main lateral branches. You will also have a large number of new vertically growing whip like stems (water sprouts) as a result of the previous years pruning, snip these off at their base. You will also have water sprouts facing away from the centre of the tree which are valuable as new lateral branches. Leave these until your final pruning.
Crossing branches - Crossing branches congest the tree but also rub off each other creating wounds in the bark. Any cut or wound is a potential entry point for disease so these must also be removed. You can see in the picture opposite 2 rubbing branches that have died, probably from disease that entered at the contact point.
Shading branches - If you have one large branch network growing directly above the other it will be shading the lower one and preventing it from producing good fruit. Choose the healthiest looking branch that fits your vision for the tree and remove the other.
Competing branches - At this point you may have reached your 25% quota but if not you can start some lighter pruning to shape the canopy of your tree. Up till now you have probably been removing large branches but we are now concentrating on the smaller branches growing from your main lateral framework. If branches are growing into the same area and competing with each other they need to be thinned out by removing them at the point where they join the main branch.
Picture bright, open space as prime real estate. If you have a number of small branches competing for that space thin them out. If you have a group of small branches in the same area remove the middle one, chances are it will solve the issue and leave room for the ones either side to breathe.
Year 3 - Depending on how much pruning you were able to do in year 2 you may have some more competing branches to remove to open out the tree. It is a simple diagram below but this is the sort of shape you are looking for. Notice how all the branches are exposed to sunlight while all the branches that were being shaded from those above have been removed.
Once you have cut out any competing branches Year 3 is more about fine tuning than major surgery. At this point we need to start to look at how the tree behaves when pruned and how we use this to help it to produce the best fruit. . As you know there are two types of cuts we can make when shaping a tree, thinning cuts and heading cuts. So far you have been using thinning cuts and removing entire branches. Heading cuts are used to shape a tree when young and are not usually required with mature trees unless as part of a restoration. To use heading cuts accurately we need to look at the types of bud on the tree and how they respond to pruning.
Growth or wood buds (Left) Growth buds are much smaller than flower buds and grow tight in to the branch or stem. They are slender and more pointed and look more scaly than downy.
Flower buds (Right) Flower buds are larger and more plump than growth buds and have a downy surface. You will easily see the difference in growth and flower buds by November. Unless you have a tip bearing (unlikely) variety flower buds grow on spurs which are short, stubby branches where the fruit is produced. I a tip bearing variety you will see the flower buds at the branch ends.
When training a tree we are concerned with the growth buds. Heading cuts are made above growth buds and will produce a new branch facing the direction the bud is pointing. For example, if we prune above a growth bud facing in to the towards the centre of the tree we will get an inward growing branch (which we don't want). By pruning above growth buds facing outwards we encourage the tree to form an open habit rather than a congested one.
As with year 2 you will have a large number of new water sprouts growing both vertically and at an angle from your lateral branches. Remove any vertical sprouts or those facing the centre of the tree. Any sprouts facing away from the trunk can now be trained to become new fruit producing branches or removed if they are growing towards a congested part of the tree.
Stand back and look for open gaps in the framework where there are no branches shading from above. Leave any outward facing sprouts that are growing towards empty areas and remove the rest. It is common for sprouts to grow in pairs, you can remove one and leave the other if it is growing in the direction you want. If you want to modify the direction of a sprout look for a growth bud facing the direction you want and prune above it at an angle of 45 degrees. You can see examples of a good pruning cut above.
As we are using heading cuts at this point (remember apical dominance) be aware that pruning new wood will result in new lateral branches being produced below the cut. Any laterals that don't fit your plan can be removed later by pruning back to their point of origin.
That's it! I hope this article has been helpful. Obviously this a general guide and might not fit your tree exactly but all the same principles apply. Here's a quick 123 reminder:
- Don't top your tree.
- Don't remove more than 25% of your tree in any given year.
- Make a small number of big cuts rather than a big number of small cuts.
- Open the center of the tree, make sure all branches have access to light.
- Remove the 3 D's, dead, diseased or damaged wood.
- Finally shape you tree using minimal heading cuts.