Pruning Notes: Restoration of a Mature, Overgrown, Apple Tree
At the end of January I had the great pleasure of working alongside Tim, a former colleague of mine from my RHS days1Said days being the dim-and-distant past of 2022 and 2023., on restoring a mature and rather overgrown apple tree in his Mum’s garden. Here’s how we approached this particular restoration pruning project.
Meet the Tree
The apple tree in question is, by my estimation, around twenty to twenty-five, maybe thirty years old. Tim has been told that it’s a dual tree; two varieties grafted onto one rootstock. Given the age and shape of the tree though, and its current state of winter dormancy, it’s impossible to identify graft points, or spot any differences in the bark or, of course, the fruit. The one clue that it could indeed be a dual-cultivar might be the way the growth on one side seems to be largely upright, whereas on the other there’s a lot of branches tending towards the horizontal, but that could just as easily be the result of the tree’s location within the garden and the growing conditions in the immediate area.
The tree has been planted in a slightly less-than-optimal location, in this case quite close to a very tall conifer hedge2Although, given the likely age of the tree, it’s equally possible that the hedge is a later addition., and in ground that’s perhaps a little heavier and wetter in winter than apple trees are happiest in. It has also been pruned intermittently over over the past few years. As a result the canopy had become over-crowded and tangled, with very long stems reaching for the sunlight to the south and away from the nearby hedge, and with plenty of sub-branching towards the end of stems that have been tip-cut in past years, presumably in an attempt to control the tree’s height.
Sadly, this tree is also suffering from multiple points of canker infection. We spotted numerous lesions, affecting a large number of branches. Again, this can be quite common in damp conditions, especially when the canopy is very close and crowded and there isn’t enough air-flow to help flush out fungal canker spores.
Here’s the tree before we began working on it. First impression, front-on with the hedge behind: it’s already obvious how unbalanced the growth is, with that large, low branch carrying a lot of weight:
From the side it was even more obvious how much of the growth is straining south-wards towards the strongest source of light, with numerous branches from the back section of the tree arching upwards and then over, through the centre of the canopy:
All that moss is a clear indicator of damp conditions, suggesting that the atmosphere in this part of the garden tends towards the humid.
How then to approach this sort of tree canopy? What are the goals, the parameters, the general methodology to adopt? Here’s what Tim and I decided on, after a good few minutes’ worth of discussion.
Goals
This tree is in a private garden and is enjoyed by the owner for its blossom and fruit, and is also occasionally used as a climbing frame by two small children. We therefore needed to maintain the tree’s general aesthetic qualities and potential for blossom production – which ruled out the option of hard-pruning back to a core framework, in order to reboot the tree’s growth over the next few years – and make it a bit safer for small humans to clamber around in.
From the perspective of the good of the tree, the key goal was to try to restore its general health, mainly by reducing the incidences of canker infection and opening up that crowded canopy, to allow in much more light and air, which will in turn hopefully reduce the chances of reinfection, weather conditions allowing.
Improving fruit productivity was a tertiary goal to those of improving the tree’s health and maintaining aesthetics, but would hopefully be achieved at the same time, as a natural consequence of that increase in light and air through the canopy.
Parameters
Bearing in mind that a mature tree that has settled into a growth pattern to suit its location, conditions and past treatment will generally continue to adopt that same growth pattern, regardless of any attempts to “correct” or significantly alter its size or shape, Tim and I discussed the best pruning strategy to adopt, in order to achieve the goals we had set. We decided on the following approach:
- The worst areas of canker infection had to be targeted for removal as a priority.
- Crowded, crossing branches needed to be thinned out considerably, particularly if they were rubbing against each other and causing damage, as per the example below, which we spotted in the centre of the canopy:
- We needed to avoid reducing the canopy in the rear, hedge-side, section of the tree by too great an amount, in case that led to the tree becoming front-heavy, and un-balanced to the point where it might develop a significant lean, or even fall.
We also knew that it would be counter-productive to attempt – as had been tried in past years – to reduce the overall height of the tree by trimming back the longer vertical branches. The often-advised general pruning method is to cut back all leaders and main sub-branches by a third – making ‘heading’ cuts – but this typically results in the regrowth pattern shown below (on a different tree), whereby three, four or five new stems emerge and grow from dormant buds around a pruning wound:
Instead, what we needed to do was aim to reduce the density of the canopy with a series of ‘thinning’ cuts, by identifying and removing individual branches, or entire branch sections, as required. Of course, we were aware that removing whole branches would still result in re-growth, but the new stems will originate from a single cut at the point-of-origin of the removed branch section, rather than multiple cut-points higher up in the canopy. Whereas the latter will inevitably result in even more thickening and over-crowding of the canopy, those new stems developing lower in the canopy structure will be easily manageable in the next phase of pruning, or they can be allowed to grow on if they looked likely to develop into useful replacements for any branches that might need to be removed in future years.
Speaking of which, it quickly became clear that we weren’t going to be able to remove every single incidence of canker infection in this first pruning session; that would result in the removal of both too much material from that counter-balancing back section of the tree, with potentially disastrous consequences, and too many branches from the rest of the canopy, which could spoil the tree’s overall aesthetics. Therefore, this restoration would be a multi-year project, and some of those potential replacement branches are likely to come in very useful in the next couple of years, as more canker-infected branches are targeted for removal.
At one point very early on, we did consider opting for a major crown-lift, by removing that aforementioned low-positioned, heavily weight-bearing branch. However, that would have resulted in a massive portion of the canopy being removed, quite possibly removing one of the two cultivars (if indeed it is dual-cultivar) from the tree in the process, and completely altering the overall aesthetic, especially once we’d removed the necessary, canker-heavy sections from the rest of the tree.
Examining the branch it was clear that it was extremely solid, with a good, obtuse growth angle and very strong woody tissue supporting the weight – therefore making the branch less likely to split away from the trunk, as acute-angled branches are prone to do, especially when they get too heavy with fruit later in the season:
There didn’t seem to be any pressing reason to remove it and we decided it was far better to ease pressure on that branch by reducing the weight of the canopy section it was supporting.
A quick note on the appropriate quantity of material to prune out: apple trees are generally robust and hugely capable of recovering from predation damage – which is in effect what pruning is, in an artificial sense – so we weren’t too worried about limiting ourselves to a nominal amount of removed material; you’ll often see something like “don’t prune any more than 20% [or 25%, or 30%, or another amount] of a tree, to avoid excessive re-growth,” which can be a useful rule of thumb, but shouldn’t be taken as a hard-and-fast requirement, if the goals and parameters of a pruning session suggest a different plan.
Methodology
Tim and I adopted a systematic approach, starting in the centre of the tree, then working outwards into that hedge-adjacent back section, before moving clockwise through the rest of the canopy.
We worked with a combination of secateurs, loppers and hand-saws, depending on whether we were snipping off small, damaged stems and stem-ends, chopping away the ends of branches that were going to be removed to reduce the weight on the final cut, or making a clean, smooth final cut at the branch point-of-origin, respectively.
Job one was removing canker infection, so in each section of the canopy the worst incidences were identified. We then traced the infected section of branch back to its point of origin on a larger branch, and examined any other sections that were growing out from that same branch. If they were also infected, or were crossing through the canopy, or duplicating and growing into the same space as a stronger nearby branch, we knew that we could remove the entire section. We continued to work along and down each branch section, towards the centre of the tree, making decisions as we went and continuing to cut as required, before moving on to the next branch section and repeating the process.
Tim, who is a considerably more svelte chap than I am, clambered into the centre of the canopy and was able to make a lot of the final saw cuts at the point-of-origin of the branch sections we were removing. Whereas I worked from the outside in, clipping died-back tips and reducing the length of the branches that were identified for removal, ready for Tim to make those final cuts.
Having two pairs of hands, and two pairs of eyes, on a job like this is incredibly valuable, allowing you to view the tree from different angles, spotting problems that might be hidden from view, and safely passing tools to each other, into and out of the canopy, as required.
Here are a couple of photos that I took part-way through the process, the first from the front, and the second from a bit further round to the side:
You can see that by this stage we had thinned out the centre and right-hand / back side of the tree considerably, whereas the left-hand / front of the tree is still to be tackled.
We also examined the moss on the trunk, but as it didn’t seem to be harming the tree’s bark, and removing it would probably have done more damage than good and would most likely have re-established itself in short order, we decided to leave it alone. Hopefully it will provide habitat for a hot of useful insect predators, and perhaps nesting material for small garden birds.
Assessment
The whole job took a couple of hours, during which we spent plenty of time discussing the principles behind the decisions we were making and the merit of removing or leaving each branch as we came to it, and keeping an eye out for potential fruit-bearing wood that we could definitely save. The time flew by, and once we had made our first thorough pass and a second quick tidy-up pass through the canopy, we stepped back to assess the end-result.
Here’s the pruned tree from the front:
And from the side:
A closer view of the much-reduced centre of the canopy, with visible pruning cuts:
And here’s one of the pruning cuts that we made in the very centre of the tree, to remove a vertical branch section that wasn’t strong enough to be a useful leader, but was a potential source for a lot of canopy-crowding regrowth:
Please note: the cut does look flattish, but it was made at enough of an angle to prevent it being horizontal; if we’d left a “bench cut” then that might casue rain water to pool on top and potentially rot the bark at the edges. Instead, I’m sure it will heal up nicely, and become a handy sparrow perch, or a foot-rest for a toddler, or be colonised by moss, in due course.
This before-and-after pic will hopefully illustrate how much of the over-crowding we were able to deal with, and how much more spacious and airy the canopy was after we finished working:
Overall, we were very happy with the work we had done. Yes, the tree is still quite crowded; there are still plenty of long branches sweeping out and across the canopy. And yes, there are still a few points of canker infection that we haven’t removed. But, as we kept reminding ourselves, this is a multi-year restoration project and we were always going to be leaving behind a few issues to revisit in future years.
I’m hoping that Tim will ask me back again next winter for restoration phase two, and if so I’m looking forward to seeing how the tree will have responded to the treatment we’ve given it. Fingers crossed it fruits well and produces some of that useful regrowth that we’re looking for.
If you have any questions or observations on this restoration pruning article, or top tips on restoration pruning that you’d like to share, please do leave a comment below, or you can email me directly if you prefer.
