Some years ago, I wrote a post about how to winter prune apples and pears, based on instructions from Bob Sherman, of Garden Organic. This post gets the most hits on this blog – it seems a topic many people want to know more about.
And I’m not surprised. Fruit tree pruning is a bit of a dark art. Lots of books and websites claim to tell you what to do, and then don’t really go into any detail. I came across another one of these just the other day – a youtube video. See what I mean?
Well, I don’t claim to know how to do it either. Bob’s instructions in my original post tell you to select about 5 or 6 framework branches, then remove all the shoots coming off these that are more than 4 years old (2 years, for pears). So, as I was doing this at the weekend, I thought ‘well, these trees are spur bearers and they need to form some spur systems – if I never prune back these long shoots until they are 4 years old, then they’ll just grow and grow. Sure, they’ll produce some fruit near the base, but not much.’ I decided to look into how to encourage spur systems to develop. I’ve a couple of reliable books I go to for hard gardening info, rather than pretty pics and inspiration: Growing Fruit and Pruning. They both say pretty much the same – this is from the Growing Fruit book (remember that flower buds are the ones that produce fruit, wood buds produce more wood):
‘Spur bearing cultivars … can be induced to form spurs. Each winter cut back a proportion of maiden laterals to four or five buds. Choose those that have insufficient room to extend as secondary branches. In the following summer, a lateral so pruned produces one or to shoots from the uppermost buds, but usually the lower buds develop into flower buds by the end of the growing season. In the following winter, cut back the laterals to the topmost flower bud, thus removing the previous summer’s growth. However, where there is room and no risk of the spur overlapping an adjoining branch, extend the spur system by cutting back to three or four wood buds on the previous summer’s growth.’
Hmm, so that suggests that the bits we leave on the scaffold branches need some further pruning to help them develop into spur systems. But then, in the Pruning book, it says:
‘Most commercial growers, who have to make a living out of fruit growing and therefore depend on heavy crops, use a system which is a compromise between the older method of spur pruning and a new system, called renewal pruning, that depends on the known tendency of both apple and pear varieties to produce flower buds on unpruned two-year old laterals. Leave strong laterals on the outer parts of the tree unpruned. During the following growing season the terminal bud on each unpruned lateral extends to produce a further maiden shoot, while most of the buds on the unpruned portion are transformed into flower buds. In winter cut back the laterals to the top-most flower bud. The following summer the cut-back lateral produces fruits. The fruited lateral can either be retained as an elongated spur system or cut back to within 1 inch of its base.’
So that seems more like what Bob’s instructions were suggesting.
Well, I started thinking about this as I was working my way through the orchard (I have 28 apple and pear trees). Then I did this research. My orchard is split by paths into 3 sections. I decided to go with the first system in the bottom section – largely because I didn’t think of it before I got to there. But the other 2 sections have been completed with the second (renewal) system. I’ll blog again on the results when I have something to report – that may be as much as a year away.
The only bit of that that doesn’t quite make sense to me is in the first quote where it talks about ‘secondary branches’ – Bob’s instructions don’t mention secondary branches. I’m sticking with focussing on the scaffold branches for now, and I’ll worry about the secondary branches (whatever they might be) in a year or two.
I hope that’ll help you decide how to move forward with your own tree pruning. I’d love to hear how you get on.