Good to see a post from you harvestman, it has become harder to step over all the trolling for argument and negativity of late. Glad to see that you are above the fray. :)

I know this isn't your main point, but plants have generally come to expect some leaf/shoot losses due to critters chomping on them. Regrowth is a plant's greatest defense (offense being the best defense). For the most part, pruning is reasonable, natural and desirable. Since most of my reading is specific to the home grower, I wouldn't be surprised what University literature might advocate. But wouldn't you agree that the two worlds are starting to converge a bit more now?

Yes MC, I agree- in general- for one thing, the idea that taste helps sell fruit and it's not all about size and color is certainly being taken seriously again, thanks, in part, to the success of Honeycrisp and other recently introduced tasty varieties including your beloved Dave Wilson pluots.

When pruning information is provided to the homeowner the tendency is to keep it basic. Even info provided for the industry usually isn't very thorough- over the years I've gotten more detailed information from publications for commercial growers like Goodfruit magazine.

Some of the best consultants don't work for universities but write articles for such magazines.

I wish some of my pruning were a bit more dwarfing. I have wanted to keep all of my trees no taller than ten feet tall. I prune every late winter, early spring and peaches sometimes after they crop. It is a battle. I have noticed that after a severe pruning which after six years I had to do, my Italian plum blossomed like crazy. This year, after 'normal' pruning it has far fewer fruiting spurs. Is that the 'dwarfing' you are talking about? Regular pruning means less fruit? This spring I had more water sprouts than usual. We had a very cold, long winter, but my trees really never looked better.

I have pruned one peach badly. It it does not produce this year it will be part of a cookout! The tree is getting too tall and I will not be able to reach the fruit. Sad, its seven years in my orchard and I hate to see it go. Pruning did it in. Early stages of orchardom! Mrs. G

Mrs G., when it is said pruning is dwarfing it is about removing vegetative wood, or at least that is when it is absolutely true. But it doesn't mean a vigorous tree doesn't respond with rampant growth to heavy pruning of any type.

How vigorous trees are is based on several factors- I manage some orchards with real farm soil- deep clay to silt loam and the trees get huge very quickly compared to my shallow silt. Plum trees I was pruning last week were insanely vigorous at one site where adjacent land it used for corn- up to 8' long, well branched annual shoots in the J. plums maybe an inch and a quarter diameter . The peaches are still putting out plenty of vigorous new wood without mulch, irrigation or nitrogen growing in a very heavy sod after 12 seasons. All trees there are being managed this way and they all grow (and fruit- though it took a while) like crazy.

The fruit is all still very high quality even though things are more vigorous than I would like. (That's a bit confusing, eh Olpea? I have my theory).

If you want your trees to stay in a smaller space, I think you should prune more in mid-summer. Leave only the new wood on the peaches you need to carry fruit the next year and the older wood carrying fruit (with enough extra growth on those pieces to support the fruit).

You can also wait until the trees are growing and you can clearly see the flower buds before you do your "winter" pruning. This may not slow them down much but you will know where your blossoms are.

3 weeks ago i checked the growth of a 4-in-1 plum on one of the varieties because it was growing way faster than the other 3 (probably 14 inches of new growth). Well, the other varieties are finally growing well (7 inches), but the variety I pruned has grown a couple inches and has started branching out below the cuts. Suffice to say pruning sparks growth and is only dwarfing if you continually check the growth.

Goyo, it spurs growth immediately below the cut - maybe even increases the overall size on that single branch, although I doubt it. The idea that pruning is dwarfing means the more you prune a tree the smaller it will be over the course of a single season and for years after.

If you have a more vigorous variety on a multiple variety tree, of course you will have to prune it again and again to keep it from dominating- like a car with a larger engine, all other things equal, it will win the race. If it gets a flat tire has it repaired it will still be the faster car.

You run into the same problem when you have a set of scaffolds with one that has double the diameter of the others. When you cut it back, you don't limit its' access to water and nitrogen. The remaining branch will be more stimulated because it receives more water and nitrogen per leaf- the capacity of the vascular structure has not been decreased, just the number of growing parts that have to share it (water, nitrogen,etc).

Its my understanding that late winter/early spring pruning is invigorating and summer pruning can dwarf. Im sure, as you posted there is more to it.

Most places I go to are university sites or fruit programs so there information should be more reliable.

Those same university sites will state that winter pruning is dwarfing to the tree but stimulating to the point directly below cuts.

It is not a question of summer being one thing and winter being entirely another. Summer pruning is said to be more affective at reducing the vigor.

For centuries espaliers have been summer pruned to keep them in their restricted spaces, now Dave Wilson is promoting summer pruning to keep 4 trees in the space of one. Mrs. G, I should have mentioned that you can find a video at their site about the kind of pruning they do to accomplish this.

The point of this post wasn't so much to discuss the difference between summer and winter pruning but to make a point about how to approach pruning various trees and shrubs according to individual need. It applies mostly to sites where trees are dependent on rain and trees are more likely to fruit themselves to a point of runting out. In the northeast this seems to be crucial when you are managing mature trees.
I don't know how much it applies to other regions.

Thanks I'll go to the Dave Wilson site. Mrs. G

I notice the need for a renewal program on peaches in particular. In my yard they sometimes stop putting on significant new wood after ~10 years. I regularly am pruning out the smaller limbs, but at that point the 1-3" limbs need to be eyed for removal. Several trees I thought were in permanent decline have come back to life by doing this.

Scott

So, I have inherited a weeping Santa Rosa plum that has a trunk about 5" wide, I've made a few attempts to prune it to a more manageable size but it just grows bigger and blooms more. None of my efforts have dwarfed the tree at all, and thinning is a time consuming job that needs to be done or the branches will break off (I learned that the hard way the first year we had the tree.)

Can I prune it a bit now, as part of the thinning process? Any advice on how to cope with a very vigorous tree that wants to bear thousands of little plums?

Peachy, here are a couple of videos that may help with summer pruning to reduce vigor. Dave Wilson has worked hard to help homeowners enjoy a wide range of their varieties in limited space.

It is much easier when you are starting from the beginning to keep a tree small- it can be dangerous to a tree to try to reduce its size too much, although you can usually get away with about a 30% crown reduction in a single year as an all purpose rule. I sometimes take out much more than that from densely branched and vigorous old apple trees but plums are not as tough that way.

There is no problem with pruning small wood to reduce the crop that I can see. I do that with peaches sometimes.

Here is a link that might be useful: Dave Wilson videos

Those videos are great! I wish I had watched the one on extreme pruning back in January, and the espalier pruning lesson was very informative.

I tried to keep to the 30% rule the times I pruned the old plum before, removing competing, crossing, and inward growing branches. It responded by putting out even more growth than I had pruned off. I think multiple summer prunings should help, it will never be a small tree but I'd just like to make it easier to pick the fruit. I have to keep reminding myself that (even though I'm 6 years into the project) this is my first time growing fruit trees so I have to allow some margin for error, it is as much about learning as it is about producing for me at this point.

There's so many wonderful plums-pluots you can grow there- the weeper isn't as good as straight SR is it?. You probably should cut it down and start anew.

I agree, there are a few other problems as well - the biggest being it was planted too close to the retaining wall so it's dangerous to pick from one side of the tree because of the 4' drop. But I'm loathe to cut down the one plum we have that bears large crops, at least until the younger trees get a bit older and bigger. An inferior homegrown plum is better than no homegrown plums ;oP

They also have a good video on grafting- you can do it a couple branches at a time.

Thanks harvestman I always get a lot from your posts. I'm always trying to avoid pruning that old fruit bearing wood to get a larger crop. Sometimes in avoiding pruning enough I cost myself the following year. You can tell you have a ton of experience. It's a fine line and it seems I prune to much and wind up with to much growth or not enough and get to little. Reading a trees needs takes time and I'm not quite there yet.

Weeping Santa Rosa is said to be a bit better than straight SR (pun unintended). I found it is sweeter on average.

It sounds like your problem is the tree is getting too tall. Just cut off the whole top(s) if you have that problem. If anything more than 1/2" or so thick is above the top of your head, cut at eye level. Or something like that. Bend over one of the long shoots produced from the wound the following spring. My SR and WSR both got too tall on me before I knew how to prune properly.

In general Japanese plums are harder to keep low than other trees. Well, pears are also hard.

Scott

It is too tall, but it's also difficult to get in to pick fruits because there are so many branches. I pruned a bit yesterday, shortening the branches I could reach and removing some that were growing in awkward places. After it is done fruiting I'll prune more aggressively, and maybe I'll post a pic when the leaves fall off and you can see the form more. It's an oddly shaped tree.

I never considered grafting, it would be a good way to try more varieties in less space. I'll have to think about it before next dormant season.

Thanks for all the advice!

Scott,
I have a few questions regarding your above comment on renewal pruning on older peach trees. Are you removing the entire 1-3 inch branch or leaving a short stub to get regrowth from dormant buds on the branch?

Same question regarding renewal pruning of smaller branches.

Thanks,
Ed

Ed, its going to produce a ton of shoots from the pruning wound however you do it. I do both kinds of removal, if the tree is too high I will head it and if there is a whole scaffold with no vigor that is needing removal I will cut it at the base. Peaches start having problems putting out shoots when the trunk gets to be around 3" in diameter. I still remove such trunk sometimes, but I make sure there is a shoot nearby to replace it. My Winblo had completely stalled so I cut down the whole tree to a single pencil shoot a foot off the ground.

Scott

Scott, I haven't had the same reliability when cutting into even 2 year wood with peaches. I never know how they will respond, but I grow mostly newer varieties that don't tend to be as cooperative as older strains.

If a variety tends to throw out new shoots from old wood without the encouragement of pruning you may be able to get away more with stubbing older wood. Such types are much easier to maintain as old but productive trees for me.

I wonder if anyone would care to "weigh in" on the summer pruning issue again. My own experience and predisposition is basically to say "prune when the loppers are sharp.....except don't prune in Autumn when the tree is preparing for winter....but every other season is okay".
As has been discussed over and over, winter pruning invigorates new shoots and summer pruning is for de-invigorating. No argument.
But here's the problem: Seattle's local gardening guru Ciscoe Morris tells people not to prune more than 10% of a fruit tree in the summer and make most of the pruning in the winter. I disagree but can not prove otherwise. My own bias is to believe that many homeowners with large trees should make most of their pruning in summer.
And an employee in charge of some of the Seattle Parks doesn't want me pruning any fruit trees after blossom time and before August because he believes the tree guru Shigo has directed that this is bad for the vigor of fruit trees and so you should either prune them in the winter or wait until August.
I don't believe that either. Once again, I believe one prunes most anytime except in Autumn......(generally speaking, local conditions may vary).
am interested in the experience of others....or any links or references. (if this should be a separate thread, please let me know).

I have little (but some) fruit experience. But I do have relevant commentary:

Celebrities/gurus like a bit of controversy. Not being at least a little different generates no press. Press is good for gurus/celebrities.

If you have fruit tress do what you think is best.

If someone who signs your paycheck tells you to prune at a certain time, as Nike says Just Do It. Then you can take the aforementioned paycheck and buy more fruit trees to properly prune at home.

Donnie, it may need to be a separate thread to bring more folks in the discussion, but your questions are of particular interest to me.

During the part of my plant education that occurred in an institution (no, not a mental asylum) the man who taught me basic tree identification and climbing with ropes was a huge disciple of Shigo. For a short time I was his, but a skeptical one.

I read all of Shigo's published books (maybe 3) and found him interesting. Every reference to experiments he made were his own experiments and involved only 2 species.

At the time I was reading everything I could about arboriculture and eventually found a book by Richard Harriis with the title "Arboriculture" printed by Prentice Hall. To my mind this book is heads and shoulders above anything else written in English about the care of woodies. Anyone particularly interested in trees should have a copy.

Shigo was a solitary genius who was in love with his own work but seemed uninterested in integrating it with the general knowledge being obtained from a much wider range of research. Harris acknowledged Shigo's contributions but took things from there, basing his book on a much wider range of information.

Amongst many tree care professionals, Shigo has obtained the status of the "Great Tree Prophet", but amongst scientists he is thought of as the person who first established a mechanical understanding of how trees deal with wounds, including pruning cuts.

I think the problem was that he took his research, and without integrating it with the general science or having any relationship with other tree scientists (he never taught at a university) created a strict protocol for pruning trees which was actually based on research intended to be used to make timber trees more productive of useable wood with the least possible labor.

He had an almost religious objection to ever topping trees or fertilizing them with free nitrogen, for instance. I went to a lectures he gave at a NAFEX meeting once (a gathering of fruit tree nuts) where he made claims that many common management practices of orchards including the above, were short sited and led to early tree death.

It was the funniest lecture I ever witnessed- Shigo had no knowledge of fruit tree care but presumed to know exactly what was right for all trees, although all his background pertained to producing lumber and not fruit.

A fruit grower attempts to produce as much quality fruit as possible on the least amount of structural wood.

Anyway, summer pruning is now an established practice in the commercial production of fruit and there in no debate on whether it can be a useful practice in the industry.

Whether fruit trees can be pruned any time is partially based on the species and on the climate where they are grown, but for many centuries espaliers have been managed primarily by summer pruning- sometimes just once when terminal buds are set and sometimes throughout the active growth of the tree.

As far as research about wound closure, the only time Shigo suggested it was terrible to prune was when they are hardening off in early Fall. He also suggested that if you prune when trees are growing, it is best to wait a few weeks after they are in full leaf to give them time to balance there energy account.

Other research has shown that the wounds will usually "heal" in any case and the main thing you need to worry about is cold injury from trees pruned before extreme cold. This issue is connected to the species and the age of the tree. Old apple trees are much tougher then a young cherry, for instance.

The other problem with time of pruning can be about disease. Trees sometimes are less prone to canker diseases if they are pruned while in growth. For peaches this means at first growth but for cherries much later.