In the “on years”, we have struggled to thin the apples hard enough and early enough to ensure return bloom the following spring. To explain: of our main varieties, the tendency to bear biennially is definitely worst in Fuji, followed by Gala and Braeburn, and then Jonagold. Pink Lady is reasonably consistent from one year to the next. We have tried lime sulphur, pine oil, removing blossom with scissors and more recently very hard winter pruning coming in to an “on year” (with light winter pruning when coming in to an “off year”). Removing blossom with scissors took forever. Lime sulphur and pine oil do work but are too severe on the tree, and are at odds with what we are trying to do in improving tree health and fruit nutritional value. We are hoping hard winter pruning will go a long way in overcoming our biennial bearing problem. [Editor's Note: You're encouraged to start new threads in this category to discuss other approaches to thinning and recovering from biennial bearing. Thanks!] The idea with the hard winter pruning is this – if you want only 150 to 200 apples on a tree, then why leave one thousand buds, with potentially six apples in each bud? If we winter prune to one bud for each apple needed, we will still have potentially six times the number of apples needed. We aim for one apple every 10 to 15cm along the branches, so we try to remove all the fruit buds in between. When trees are pruned this hard, they will tend to push dormant buds out of the bark along the branches, most of which will develop into fruit spurs for flowers the following year. If we know a tree is due to have a light flowering, we don’t prune very hard at all, reasoning that we will need pretty well all the fruit buds that are there. Light pruning will also result in less vigorous growth in spring on these light crop trees. That is the theory, but we haven’t been doing it long enough to know if it will really overcome our problem. Just another “work in progress”, with lots more questions than there are answers. We suspect nutrition and rootstock are also playing a part in biennial bearing.

This is a very interesting subject - using alternate winter pruning to overcome alternate bearing. I have been playing this game for some time, but I am not sure it really works... I must say however that I have been doing the opposite, i.e. prune hard on the off year. The reasonimg is as follows: let's assume I prune this winter (2010) a tree that had a large crop in 2009 and for which I expect a small crop in 2010. Here it goes: winter 2010 - hard prune (off year) summer 2010 - vigorous growth and small crop summer 2011 - formation of fruit buds (this is an "on" year, big crop) fall 2012 - increased crop on an "off" year As you can see, the difference between my assumptions and yours is that I assume fruit buds are mostly formed on 2 year wood while you assume fruit buds are mostly formed on 1 year wood... I must say I did have some success with some trees only. Some others didn't respond at all. Well, we all know that some varieties are extremely biennal and just about nothing will work. I now also think that weather the fruit buds will form on 1 or 2 year old wood may depend in part on the variety - which would explain why my system works better on some varieties. Unfortunately, there are many other factors that may have an influence and it is very difficult to be sure of the effects of my interventions - we are working on living bodies after all! I would be very interested in having other's opinions on this... Claude

Claude, a point of clarification. We are relying on fruit buds to be formed on wood that is 3 or 4 years old (or older), from buds that were dormant and would not have pushed out if the tree was not pruned hard. A lot of these buds do not form an extending shoot - they form a rosette of leaves with a fruit bud for next spring in the centre. The method does not rely on fruit buds being formed on one year old wood.