Pruning in early winter, mid winter, late winter, early spring... what's the difference?

We have a small apple orchard established with trees I would say are 10+ years old that haven't been pruned in a long time. Lots of overlapping branches, and fairly overcrowded.

We want to prune for maximum yield, flavour and sweet juicyness for cider and vinegar creations.

I have read many differing opinions on when to prune, some say early spring, after the coldest parts have passed, some say other times - what's the difference?

I'm very new to this, but some of the apples didn't seem so great compared to others on the same tree... while other apples on the same tree seemed to be crispy and full of juice and flavour. Has this got to do with old branches or perhaps sick branches?

A few other questions:

Would a floury kind of apple have anything to do with a branch that has lost its vigour?

Does a younger branch create more sugar juice content apples or is this unrelated?

We had one tree that is quite large but must have only produced 5 apples. It looks like it could have produced 100's - but it's very overcrowded.

Thanks for any pointers!

Rob

I have also observed that the biggest and best apples grow on the younger branches, so pruning for branch renewal makes sense to me. However, those may have been trees with tip-bearing tendencies. For spur-bearing trees you'd want to allow enough time for spur systems to form.

I think a lot of the difference observed in fruit on the same tree is related to differences in sun exposure.

For apples, my rule of thumb is you can prune anytime, except late fall if you have hard freezes in your climate that would freeze new growth. Summer pruning tends to dampen the trees regrowth response and is good for e.g. managing vigorous trees; winter pruning tends to stimulate growth and is good for less vigorous trees.

Hi Rob,
I only prune to clear problems like overcrowding or branch on branch rubbing, I mostly do this in spring after the blossoms have fallen. I have managed the same orchard for 20 years now, at first pruning as I was taught, then not pruning and letting all the higher up apples freeze and feed the birds whenever there is a thaw. Yesterday there were maybe 200 birds noisily feasting on thawed apples. As most permies already know, all fertility comes from the wild, so enticing them to bring it to you is the easiest way to increase your harvest.
Don't worry about the tree with only 5 apples on it, apple trees don't produce every year. Next year that tree will be your biggest producer!
I have a closed system, no inputs and no waste output. The branches(only small branches should be pruned), leaves and fallen fruit is all buried in a sort of mini hugelbeet. Each tree has its own bed where I also grow early season vegetables in the spring before the trees fully leaf out and then grains and potatoes through the summer.
It's hard to express the changes this system has brought about because they are subjective, but I know that this is the way for me. I will be using and promoting this system for the rest of my life.
I posted a picture of our best apple tree here Mother tree photos

Thanks a lot for this information.

Bill: the tree(s) I was referring to that only produced a hand full of apples also produced the same amount last year - is it likely a tree doesn't produce much of anything for multiple years in a row?

Would love to see more shots from your other trees - or do you prune them all the same as the mother?

We would really like to make the place much more fun for the wild. We did leave many of the high apples to freeze this year and it was really great to see the birds coming. I know this time last year there were no birds but they've stuck around because the trees weren't stripped bare so that is great.

Something else worth mentioning is that most of these apple trees don't have any nitrogen fixers anywhere near them. We do have a sea buckthorn stand near our smallest tree which is about 1/3 the size of the other trees, and it was cool to see how that one produced as much as the others and also the tastiest. It is also however a different type of apple as well.

Patrick: I'll have to do some more research to work out whether they are tip-bearing or spur-bearing. Thanks for mentioning that as I had no idea about it.

When a Fruit tree has to many branches (center of tree gets no sunlight) it is time to prune to thin the branches. First and foremost for pruning any tree is to remove any branches that cross over or under a thicker main branch.
Once you have those removed it is time to thin for sun penetration. This is where you will remove enough branches to allow sunlight to fall on every branch of the tree. This can be done by several methods; overall thinning, V center thinning, or triple V thinning (the least favorite of mine since this method can lead to issues later on). I normally use the center V method because it allows me to get to all the fruit easily as well as providing full sun penetration.

In France I have seen Apple trees that were pollarded every winter. These trees grow a Nob at the termination point of the trunk, from which all the new branches sprout in the spring, the varieties were all tip bearing trees.

I've never tried to accomplish this type of pollarding because it seems healthier, in my own opinion, for the tree to retain the main branches from a pruning session.

The way the tree sets fruit is also an important factor in how much to prune. If the variety is a spur bearer, you need to keep the last years growth since that is where the fruit will be set. If it is a tip bearer, then it is the new growth that will bear the fruit.

Bryant RedHawk wrote:
In France I have seen Apple trees that were pollarded every winter. These trees grow a Nob at the termination point of the trunk, from which all the new branches sprout in the spring, the varieties were all tip bearing trees.

I've never tried to accomplish this type of pollarding because it seems healthier, in my own opinion, for the tree to retain the main branches from a pruning session.

The area where I live had a large number of Swiss settlers and, their preferred pruning style here is as you described. I see Swiss Method (as it is called here and in Canada - it was first described by a Swiss horticulturalist) pruned apple trees throughout the area. Coincidentally, I started a new post about this method this morning. I know little about it - reason for the post - so I just ordered "Ecological Production of Fruit in the North" which is a book about the Swiss Method. (It does have other names elsewhere.).

Patrick Mann wrote:
For apples, my rule of thumb is you can prune anytime, except late fall if you have hard freezes in your climate that would freeze new growth. Summer pruning tends to dampen the trees regrowth response and is good for e.g. managing vigorous trees; winter pruning tends to stimulate growth and is good for less vigorous trees.

Good points Patrick.

Since this post is about the differences in pruning during different seasons, I thought I would add a few twigs to the fire. The effects of pruning and the level of cambium activity are directly correlated.

The cambium layer is at its highest level of activity from early Spring to mid Summer (climate dependent). Buds become active and growth is vigorous during this period. Apical dominance directs most growth, but not all growth, to the shoot tip. Cut off the shoot tip during this period will induce buds further down the shoot to start growing - many of them! Water sprouts will form readily. But, an active cambium means the cuts will heal quickly. Also, the "Spring wood" of this year's growth ring forms.

Cambial activity slows greatly in mid Summer to early Fall (climate dependent). In mid Summer, the level of cambium activity decreases, but the cambium does not become inactive. Growth of shoots slows and almost stops, and this year's buds start to harden for dormancy. The"Summer wood" of this year's growth ring forms during this period. To me, this is the best time to prune: dry weather, rapid healing, less rampant growth and water sprouts (which also mean more cuts exposed to disease), etc.

During Winter, there is no cambial activity (an active cambium would be producing new cells which are highly vulnerable to death by freezing) and the tree remains dormant waiting for the warmer weather of Spring to start a flush of new growth.

So, pruning in Winter is, in at least one way, like pruning in Spring with regard to the eager growth of water sprouts as the tree is just waiting a bit longer to start growth with the warmer weather of Spring.

Just in case someone is interested, here are the how's and why's of my pruning timing. Obviously, there's a lot more to pruning than timing. Learn what you can about what a tree is doing throughout the year and how it will respond to your pruning at any given time of year.

First, one good method of timing pruning is to closely observe the condition of the lateral and terminal buds on the tree.

Note: The months listed are meant to be only approximate. Climate region and yearly regional weather variations will affect pruning timing.

1. Minimal or no pruning while the buds are completely dormant:  
~November to ~January

   Pruning is not ideal because an
   inactive cambium means no
   healing occurs during this period
   which leaves cuts exposed to
   disease entry for a prolonged
   period.

   It is OK to prune damaged, dead,
   and diseased wood.

2. Spring pruning is done just before or just as the buds begin to swell in Spring:  
~February and ~March

   Prune now for changing tree
   shape by encouraging the growth
   of new limbs.

   Pruning at this time stimulates
   growth which can be vigorous
   and produce numerous water
   sprouts (Especially in stone fruits
   such as plums.).

   To a degree, the heavier the
   pruning, the heavier the growth
   of new shoots this year.

   Don't over prune - remove no
   more than about 1/3 of the tree.

   If you don't need to Spring prune,
   it might be better to save it for
   the Summer.

   The Good:
     Abundant, vigorous growth
     provides many new limbs for
     reshaping and revitalizing the
     tree.

     Without leaves, the structure of
     the tree can be clearly seen, and
     access for pruning is easy..

     No fruit present to damage or
     knock off the tree.
   
   The Bad:
     Pruning at this time encourages
     heavy growth.

     Expect a lot of water sprouts,
     especially with stone fruit trees.

     More cuts increases the chance
     of disease entry.

     Rainy, humid, cool weather
     increases the chance of disease
     entry.

     High insect activity increases
     the chance of disease entry.

3. Summer pruning is done when shoot growth has stopped and the buds are beginning to harden off, or have hardened off. They are now enclosed in bud scales and look like a tight little bud. The cambium should still be active enough to heal and seal the cuts.
~July to ~August (September)

   Pruning now does not encourage
   new growth this year, but affects
   the new growth next Spring.

   Prune now to minimize the
   number of new limbs that sprout
   next Spring, especially water
   sprouts.

   Well located water sprouts can
   be left to become useful fruiting
   limbs.

   The Good:
     Fewer water sprouts and less
     rampant growth.

     This is the best time to remove
     or head-back this year's water
     sprouts.

     The growth of fewer new shoots
     (ie. water sprouts) reduces the
     chance of disease entry since
     less corrective pruning will be
     needed.

     Lower insect activity decreases
     the chance of disease entry.

   The Bad:
     Leaves make it hard to see the
     structure of the tree and make
     access for pruning more
     difficult.

     Presence of fruit means it can
     be damaged or knocked off the
     tree, and some will be cut off.
     Some fruit loss occurs.

The Ugly:  clean-up