It’s interesting how in apples the general consensus is that it is sun exposed bark that is the problem, but I think it has more to do with simply reducing the flow of sap when you reduce the amount of canopy, if the sap is moving rapidly through transpiration it wont get super heated even when bark is exposed.
This is something that actually hasn’t been researched to my knowledge. All I know is that it seems bark can be fully exposed to hot sun and not damaged as long is there is adequate foliage pulling sap. But shade also is going to reduce the temperature of the cambium (actually, I believe that is what is being damaged- the bark is mostly dead).
Most of the canker I have dealt with is the perennial (fungal) kind. It’s pretty easy to recognize. It’s an ongoing yearly battle between the tree and the canker at the canker site (hence the word perennial) . It seems in many locations, the trees eventually succumb to the canker. It doesn’t happen so much here. The vigor of the trees generally keeps the canker from spreading enough to girdle.
I do have some relatively sudden dieback of scaffolds which I suspect could be bacterial canker, though I’ve not verified it. It acts like bacterial canker in that it’s fairly sudden, and tends to stop as temps warm up, but I haven’t really seen much gummosis, which is associated with bacterial canker, although I haven’t really looked hard for the sap. When an occasional scaffold dies, we just cut it off and move on.
Like fungal canker, bacterial canker is considered a “cold” weather disease.
I think my little Red Haven is looking quite promising. Would love any constructive advice - as to pruning. I have this Red Haven and a ‘revived from the dead’ Indian Free. I thought it was dead, but cut it way back - and it ‘came back’ . . . although VERY short! LOL I also have a Mericrest Nectarine and a Harko. Only the Red Haven has fruit. This is the second season for all.
I am having a hard time with my apples. ? I just don’t know how to prune them, and need some advice. I read the ‘diagrams’ and just can’t ‘get it’. I tend to want to do the ‘open vase’ thing on just about everything . . . Can’t seem to get the hang of the modified central leader, etc. Any advice? I’ll post the pics I have. Thanks.
I have apples planted all along the back of my pomegranate ‘orchard’. The Pink Lady seems to be doing well. I also have a Goldrush. A Mutsu. And an Ashmead’s Kernel. Same pruning ‘problem’ with all of them. Lots of scaffold branches - and don’t know what to get rid of!
Red Haven - open center. I trimmed the length of the branches back, since this photo. And sorry . . . photo is very ‘foreshortened’.
And below . . . Paw Paws that finally ‘took off’ this spring. They have been in the ground for a few years, with little ‘activity’. We have 3 of them.
Your Indian Free is on the way to your scaffold selection, think positive! Often our country stores have fruit trees for sale, but they are way to tall/developed to have good scaffold potential. I like small trees with good branching down low. .Peach trees grow so fast
Should I lop off the tops of my apples ‘at some point’ soon?
In late winter? Sooner?
I read here, that summer pruning is preferable . . . but that is a drastic ‘lop’!
They are all quite tall. Some reaching over 5 feet. I will get out the old ‘modified central leader’ tutorial again - and see if I can ‘get it’ this time.
I am not at home, at the moment . . . but I should take shots of, and post the other apple trees. They are not pruned much, yet . . . and would demo what I am talking about much better. I will take more pics and get the forum’s feedback. Thanks.
You can use notching to get scaffolds down lower on the tree. You will still need to remove some of the existing upper branches to redirect some of the vigor to the notched buds / branches, but you wont have to do a severe heading cut.
I would also do more limb spreading, it will give you a lower branch structure and possibly more fruit on those branches.
it sounds lilke Richard Harris’s book would be very interesting lecture. At the moment it is not available for me for a price I am willing to pay. The cheapest I found is Euro 164,00 for a used paperback version…
If possible could you please sum up in a short note what he found out about best pruning time? Does he advocate (late) summer pruning even when doing substantial pruning or at least found out it is without detrimental effects for a tree (even a weaker tree)?
From what you wrote before I would suspect that single man conjectures are not that far from what Prof. Harris might have observed about pruning effects (not only wounding). And in principle he agrees with what Drew adviced too. He just warns to do substantial pruning in late summer. Wound healing is still better then than in winter time. But a tree is weakened by this practise (his opinion). Depending on the condition of the tree that might be decisive. In professional recommendations for arborists here summer pruning is advocated as the best time for pruning. That includes late summer pruning of very old trees. He advises against that practise. I found that to be comprehensible. Maybe that is overcautious?
I myself have not seen this happen. Not saying he’s wrong. I just have not observed any problems like this in 7 years. I won’t prune after August 1st usually though. That gives my trees 2,5 to 3 months to prep for dormant season. I still harvest figs here in early November. I guess I don’t consider my practice as late pruning.
We do know pruning can stimulate growth and lowers hardiness some, so it makes sense not to prune late. I have had no ill effects by stopping pruning the first week of August. Seems trees have plenty of time to prep for winter.
Very helpful pictures of your summer peach pruning! I rip my upright shoots out too when I have time, but not as much as you do. Probably about a bushel or a huge armful of shoots per tree. From what I understand its standard practice for peach orchard in my area.
Carot, I started to read the book this morning and when some of the claims seemed dated I looked up when the book was published and found out it was back in 1955, so no wonder.
I’m afraid the book won’t answer your questions although it is full of interesting information- however, if you aren’t well versed in the current literature, it may be difficult to know what info is still valid.
When I get a chance, I will try to find a recent source of information on the specifics of pruning related to season.
Let me know how you like it. 25 years ago when I was a student at the Bronx Botanical Garden, I read every book on trees in their library- at the time Harris’s book was head, shoulders and branches above any other book I could find as far a being comprehensive, well organized and clearly written with plenty of helpful photos and drawings.
I was taking classes from a teacher who was a Shigo acolyte, the man who discovered that pruning compounds don’t really work and did a lot of important research concerning how trees “heal”, best time for pruning and where to best make cuts.
He used one of Shigo’s books in his class and I showed him Harris’s book. It had references to Shigo’s research but also to a lot of other people’s studies and the teacher was impressed. A few years later I noticed he was using the Harris book in the same class.
It’s really too bad he never wrote a book aimed at home-owners with trees on their land and too badder that most arborists have never read the book he did write.
Alan, thank you very much for the effort. I am a little short on time in the moment. But I will dive into it for sure, thanks again. I took a short glance at the pdf of Prof. Harris about the care for fruit trees. He has quite a unique stile of describing complex situations and I like that a lot. He points out things very comprehensible.
Keep looking for his arboriculture book. Used copies are available in the states for much less than the one you found, and I assume you could ship it to wherever in Europe you reside.
Attached is a photo of our 3 Red Havens, closest 3 trees. The trees farther away are Cherry trees. You can see a small pile of water sprouts at the base.
At this time of the early summer, I’d take quite a bit more wood off. Much more bushy than I’d like this time of the year.
Make sure you just have your scaffolds chosen (generally 3 scaffolds) and remove everything else on the trunk. Then remove more stuff pointing mostly vertical. If something is pointing down too much, remove it.
The problem is that if you leave that much foliage on now, it will just get more shaded and cause negative effects on the lower foliage.
Thank you. I do have well established scaffolds, just hard to see from the elevated view from our raised deck. I’ll get a better internal photo. After my dormant pruning, I could step through the tree, over the scaffolds.I felt like I had the " can you throw a cat through the tree" criteria.
The scaffolds had a lot of water sprouts shooting straight up soon after. I really wanted to have fruiting wood down low on the scaffolds. But all I got was water shoots! I have removed much of the water sprouts off the scaffolds down low. Now the terminals of the scaffolds are real bushy, with more darn water sprouts. There are also a lot of overlapping branching scaffold to scaffold.
I learned the lesson from last year that a water sprout allowed to grow will take all the energy/growth potential from the scaffold.
Is there still enough growing time for fruiting wood to grow where I want it? I feel I’m a bit late in getting the water sprout wood out and letting sun light hit the much less vigorous proper fruit wood to “catch up” . My understanding is that the buds will soon be either leaf buds or bloom buds.
I’ll start much sooner next year, so I’m removing 4 inch water sprouts instead of 3 ft shoots.
