Friday, March 27, 2015

Pruning the two apple trees

I don’t have much experience pruning trees other than removing low branches.  Most large yard trees can be treated with benign neglect.  Fruit trees are another thing altogether.  Shaping the tree properly in its early years can have a strong impact on its capacity to bear fruit later on.  I wanted to get it right, but for a novice like me pruning a young apple tree is like driving at night with the headlights off.

I planted two apple trees three years ago (I think), a Golden Delicious and a Fuji.  They were in pots and had some lateral branches on the main stem.   The Golden Delicious is now about 10 feet tall, while the Fuji, with a central leader, is more than 12 feet in height.  I’ve made attempts over the years to shape their growth by removing some lateral branches and vertical growth.  This year I realized that both trees needed a more aggressive pruning to shape their growth as they approach maturity.
The thing about pruning to consider is not what the tree looks like just after it is pruned, because at the end of the growing season it will look quite a bit different.  The manner in which the tree is pruned affects the manner in which it grows.  One has to envision what a pruning cut will produce in branches in the years to come. 
I checked out some books from the library on pruning, some helpful, others not at all.   Currently many resources recommend a central leader tree with the largest branches low and smaller branches high for maximum fruit production, assuming I guess that the rootstock the tree is grafted to will prevent the tree from growing excessively tall.   Two or three whorls of well-spaced scaffold laterals are allowed to establish themselves.  Unfortunately the tree rarely cooperates with the ideal. 
I already knew that trees grow at their tips to increase length and the phloem layer just beneath the bark produces wood and adds girth.  Trees don’t grow out of the ground and a branch always remains at its initial height on the trunk.   During the winter chemical energy is stored in the roots and in the spring  the sap moves up to feed the opening buds.  Pruning removes buds, meaning that as sugars move up the tree in spring the chemical energy is distributed to fewer buds.   It seems counterintuitive, but a weak branch will grow more if pruned more severely than a strong branch. 
While pruning new growth back a few buds will stimulate growth, completely removing a branch at the branch collar ends that branch for good.  However, if you leave a short stub that branch may well start a new bud and ultimately a new replacement branch.   This branch was removed because there were two branches arising at the same height of the trunk. 
Two weeks ago with cutting tools in hand I set about pruning both trees.  The Golden Delicious tree is something of a problem tree.  It has a large lower side branch at about a 45 degree angle, really not enough, although the crotch appears solid.  Maybe I should have removed it early on, but there were few other scaffold branches to work with so I left it on.   This is the tree before pruning.  It had a large number of watersprouts and crossing branches from last year's growth.

Last year this tree lost its central leader.  A high branch came off the leader at an acute angle and I planned to cut this branch off when the tree went dormant, but circumstances forced my hand.  Last summer I was trying to spray the leader with some Neem oil and as I was pulling down the leader to spray its leaves the crotch broke.  The leader tore off, leaving the uppermost branch and a large gash in the trunk. The tear has healed partially but it may not heal strong enough to support the weight above it.  Next winter I'll decide whether to remove the topmost branch entirely.

This is the same tree after pruning.  It looks severe, but most of the mass of the tree remains.  With the central leader gone, the tree is best described as a half-standard.  In all likelihood the uppermost branch will have to be cut off below the wound but I felt that, for this year, enough wood had been removed.

The Fuji has a much better fan shape and was easier to prune, although some thinning was needed. Many of the laterals were too closely spaced had to be removed.  You can’t see it well in this picture since the shot doesn't go high enough, but an upper branch matched the central leader in height and one of them had to go, otherwise the tree would have two leaders.

This is the same tree after pruning. I tried to thin out the upper branches more in order to let light into the lower branches.  The central leader is reaching for the skies, and it may well have to be removed because it will be hard to reach apples up there.   It looks like the tree will flower this year and produce a few apples.  For the time being I’ll leave the leader in place, and see if the first years’ fruit production will stop the vertical growth.  Any reader’s suggestions are welcome.


Mark Willis said...

I'm not an expert on fruit trees, so I'm not going to offer any advice! My (two) fruit trees are grown as Minarettes - very slim indeed - so major pruning is never required. Like you, I have found that advice on how to prune is very variable. It sounds to me as if you have done the right thing though. The fact that you have researched it, and planned it in advance, has to be a good sign!

Daphne Gould said...

I just don't get pruning apple trees. I'm pretty good with the peaches though. I can shape a peach and get it to look like I want. The apples are just hard. They never want to grow a branch where I want them to. I'm doing just OK with the espaliered apples. The apples in the back I'll have to cut off some major branches near the bottom as the snow really damaged them. They were too close to the ground anyway. I should have cut them off long ago.

Margaret said...

You have done a fantastic job pruning those trees - I'm quite envious! I have two books on fruit tree pruning and am still too scared to do any major cuts. As you pointed out, actual trees rarely resemble those neat little diagrams you see in books.

Right now I have a plum & cherry tree that are going into their 5th year and I have only done the most cursory of pruning up until now. I will definitely have to take hold of the secateurs & really have a go at them this year, especially the plum. As for the new apple trees I'll be planting this spring - I have no idea what they will be like, but hope that they don't "need" any drastic cuts as I really don't think I would be able to go through with it.

Eight Gate Farm NH said...

Yes, apples are a challenge--not the least of which is their bark is really thin and tears easily no matter how careful you are. My trees are old and suffered from neglect before I got to the property. I'm gradually trying to lower their height and get to the classic umbrella-shape you see in the orchards, plus removing the yearly suckers. Normally I would have done the yearly pruning by now, but there's just too much snow. More work piling up!

JsmithNYC said...

Apple trees have never really been easy. Thanks for the great article. Much appreciated. Tree Service Brooklyn NY

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