Don't know the answer to your question, but I feel your pain.

A limb on my nectarine went down about 10 days ago due to being heavy with fruit & raccoons. I cut the hangnail, thinking I didn't want a strip of bark to run down the limb from the break and cause further damage. Cut it cleanly back to the nearest fork. Thought about sticking the limb in a 5 gal bucket with water, to see if the fruit would ripen on the branch, but then decided to pick all the fruit, though small and green. They ripened kinda ok indoors, despite being picked way early.

Thinking I will be doing a heavy summer pruning in a couple weeks to get this tree in better shape for next year.

I would do a clean cut removal of the branch now, and seal the cut. It's just about time for maximum borer activity, and you don't want to give them a Christmas present.

Also, you should never do heavy summer pruning on peach/nectarine trees.

Rayrose, do you have any information about the use of sealant to prevent borers? I haven't read of any advantages of using these compounds and my curiosity is genuine, as I don't live in an area where lesser peach tree borer seems a common problem. I speak from a position of practical ignorance.

Also, why do you particularly proscribe against heavy summer pruning of peach trees? I have heard of commercial operations doing all their pruning immediately following harvest. Someone on this forum said he worked on an orchard in Israel and that a common method there is to aggressively prune peach trees immediately after harvest to grow wood that would carry next years crop.

Once again, I am speaking from practical ignorance and genuine curiosity.

I agree with recommendations of removing the broken branch and also to figure out why it broke. Sometimes branches are weak because they are too narrow or too large in ratio to the trunk (or branch to which they are attached). With peaches, sometimes fruit is not thinned enough.

It used to be common in CA to train trees with three fairly narrow angled leaders and run a ring of rope around them before they became too heavy with fruit to prevent breakage.

Young trees sometimes require support with crutches or rope, but I think a well trained tree with healthy wood should eventually be able to support its crop if properly thinned. wood. At least barring very heavy winds.

Rose growers always seal pruning cuts after the spring prune, in order to keep out borers. It's a standard practice. Borers attack roses just as much as they do peaches, nectarines and plums.
They seek out open wounds, and this is the beginning of borer season in the southeast. I've lost more than one rose bush, because I failed to seal pruning cuts. When I prune my peaches and plums, I always seal the cuts. The only borer entry damage that i get are from cracks in the bark that I can't seal.

As far as heavy summer pruning of peaches, it is very much discouraged by the peach experts at Clemson and Byron. It encourages not only fungal gummosis, but also peach tree short life. Just yesterday, I had a very long conversation with Tom Beckman, the horticulturist at USDA at Byron, GA. He's their peach specialist and has conducted many peach studies regarding fungal gummosis. I've also had similar conversations with Greg Henderson, who is the Clemson peach expert for Edgefield county, SC, which is primary commercial peach growing country in SC. They both highly discourage heavy summer pruning of peaches. The heavy pruning occurs right before bud break.

Hi Drew:

Unfortunately, the SAME magazine in a different article recommends sealing the cuts. If you give totally conflicting advice, you don't have to worry about being wrong. But it doesn't help much.

Here is a link that might be useful: Rose Magazine article ( opposite the other one)

The article I pointed to also mentions the use of white glue. So I don't see any conflict in advice?
Yes some sealants are useful like glue, and bee's wax. But the asphalt sealers can cause more problems. Neither article recommends using that product. It seems with roses if you have borer's you might want to seal cuts. But I'm not sure that applies to peach trees too?
Advising to seal this peach tree we are talking about is really the question. So are you suggesting using white glue on this peach tree?

This post was edited by Drew51 on Wed, Jul 17, 13 at 17:00

Thank you RR for your substantial response. Here the Cornell recommendation is to prune peaches shortly after they begin growth to counter gummosis, as they close wounds more quickly when they are in growth, so I would think that mid-summer pruning could offer similar advantage. I'd really have to see some research to buy into another interpretation but I'm pretty arrogant that way. If your advice is based on conversation with these experts I can see your point.

I don't believe that common wisdom of rose growers is necessarily helpful to peach growers and some summer pruning of peaches is probably recommended by your own specialists probably without the use of sealants. I'm pretty sure commercial growers down there never use sealants after pruning. How would winter or spring cuts be so much less vulnerable to borers than summer cuts? Why not ask your peach experts next time you talk to them. I'm curious if they consider sealants a helpful borer preventive.

The whole discussion is about heavy summer pruning, not normal summer pruning. No one discourages normal summer pruning. I've already stated the reasons against heavy summer pruning. After heavy winter pruning, which is done here in January, dormant oil sprays are used to smother and kill any eggs that are laid. Commercial growers can't justify the expense of using sealants. Hence the dormant oil sprays. Back yard growers use the same approach.
This thread started with the poster dealing with just one large broken branch. It's much easier to seal one cut, than trying to time the cut, with the planned regular borer spray that we do here in the middle of august. Whether or not he seals the cut is his decision. The poster asked for advice, and I advised what I would do, if I were in his shoes.

I'm curious- how would you define heavy vs normal summer pruning? Last week I pruned my peach trees for the first time (2 year old) and removed 2-3 feet of growth (pruning either entire branches, or cutting to a side branch) to bring them down to ~9 feet. Would that be considered heavy, or normal pruning?

Rayrose, I'm engaging in discussion- not trying to suggest your advice is bad. This is a forum for more than just simple advice and a lot of people are interested in why and not just proscribed directions from "experts".

These experts often contradict each other but if you have a sense of the reasoning and research behind advice you can better learn how to deal with problems from a point of actual understanding. I think that's how you get good at most anything.

I believe the reason sealants are no longer recommended is that they've generally been found not useful, at best, in research. If you have research to counter this, please forward it- I'd much rather stand corrected than remain ignorant. Many horticultural traditions are found wanting when put to actual trial.

Don't you find it interesting that Cornell recommends pruning peach trees when they are in growth to help prevent gummosis, while your experts suggest pruning during peak dormancy? It may be based on weather conditions but I suspect one or the other side is wrong and I'm very curious to know which.

Once again, the discussion is about HEAVY summer pruning, not normal summer pruning. Everything that I posted, including the recommendations from the experts, here in the south, is about HEAVY summer pruning.

Bob, what you did sounds like heavy pruning. Summer pruning on peaches would be limited to basically keeping the open vase system open, and removing water sprouts and other limbs with undesirable angles.

I'm curious why these experts would be talking about heavy summer peach pruning- has that ever been a practice in southern peach growing? I've only heard of it practiced, as I mentioned, in Israel, but that was simply a comment by a forum member who spent a summer on a commercial peach farm there. He seemed to know what he was talking about, though

Late summer annual peach pruning, however, has been practiced a great deal, and was recommended long ago for helping peaches survive midwest winters. Scott has posted information about this.

One thing I'm careful about is not to remove too much small wood when a tree is still holding peaches- excessive summer pruning can reduce brix.

Almost all of what I pruned was new growth, most from the center of the tree. The tallest tree was around 7.5' this spring and grew a lot this year- I cut back from ~12' to 9'. These are my first peach trees, so I'm not sure if that is excessive vigor, or just par for the course with peaches.

I'll keep an eye on the prune sites to see if any issues occur.

I just spent some time searching the internet about pruning time and Leucostoma canker and it was interesting to me to see it is late summer pruning that is strongly advised against to prevent infection. I will now reconsider doing that again even though I suffered no consequences from doing it last year.

Growers that follow the Dave Wilson methods prune stonefruit trees very vigorously in mid-summer to keep them in bounds. But this is most tested in dry west coast conditions.

I actually haven't had issues with canker on the many peach trees I manage at a wide variety of sites. I wonder if it is less a problem in home orchard situations.

They're talking about heavy summer pruning, in order keep people, mainly home gardeners, from doing it. Many home gardeners don't know how to prune peach trees, or any other trees for that matter. That's why Clemson has a whole website, devoted to home gardeners.
Fungal Gummosis, as I understand it, is not a California problem, because of the dry conditions. But according to Tom Beckman, it's a major problem for California pistachio growers. But for peach growers in hot and humid areas it is a big concern. Mainly because there is no known cure, and once infected, there's nothing you can do, except monitor the trees and try to limit the severity of the infection. If the infection is severe enough, it can limit tree lifetime and productivity by 40%.

This post was edited by rayrose on Fri, Jul 19, 13 at 17:34