I view this as a good time to prune peaches. The only bad time is when really cold weather is coming in the next few weeks.

Scott

Cornell thinks the best time to prune peaches is after they bud out in spring. It's supposed to reduce the threat of canker as the sooner the wounds close the less the danger.

I'm not saying that Scott isn't right, but there is a chance he'd be singing a different tune if he was in Z5. I prune most peaches I manage in late winter or early spring just because I have too much to do when they're in bloom and I don't want to return to sites after pruning everything else just to do a few peach trees.

Haven't had any canker issues which is one reason that I think Scott's timing may usually be fine as well.

Thanks Scott and Alan. I'm going to give it a go as soon as the rain stops. luke

Hman, I just looked up some studies and the only conclusion I found is there is no consistent conclusion - different studies got different results. See e.g. "Diseases of temperate zone tree fruit and nut crops." While wounds don't close as fast in the winter, the canker is dormant then; in the spring it is in its most active period. So there are contradictory indicators and so the inconclusive studies are not surprising in that light.

Scott

I am not aware of the research Cornell's guidelines are based on but the guidelines themselves are very specific on timing of pruning peach trees. I ignore their recommendations on this myself and would be inclined to follow Rutgers instead, when it comes to growing peaches, but until I have a problem with canker, convenience will be my primary motivator.

You seem to be trying to use the research to justify your timing, but I believe wounds close very slowly in late summer- early fall when trees are hardening off- at least with most forest species, according to Alex Shigo's research. I've no idea how active canker is at this time.

http://agdev.anr.udel.edu/weeklycropupdate/?p=1671

Here's something from Rutgers

Hman, I am basically following the "don't prune when cold" part of those Rutgers guidelines, I don't prune peaches in winter. They say don't prune after Sept but don't give any good reason why Oct or early Nov pruning is bad.

I looked around for other guidelines and found in England they believe you should not prune in spring due to high disease activity. In their view summer is the best time and I tend to agree with that, there is less canker activity than spring and the wounds are healing quickest. But, I have too much pruning to do and too little time to do it in so that doesn't work so well for me.

My personal experience with canker on peaches is the main cause of cankers is lack of light. I had a whole stand that was cankered and when the big tree blocking their sun fell the cankers all cleared up. Also, the infection points just seem to be along the main trunk where there was never any cut, not at pruning points. Cherries on the other hand are highly susceptible to cankers at pruning points.

Scott

Here is a link that might be useful: RHS canker advice

Well Scott, you have more experience with canker than I do. I just thought I'd put out the guidelines by universities that oversee a huge amount of commercial production in relatively cold climates.

England has no peach industry as far as I know. Conditions there are too cool for the most part and they have no winter.

I prune a lot in summer as well- just to keep my trees open and light on the small wood that will bear my crop the following year. I'd say I do the majority of my pruning then. First in late spring I remove excessively vigorous sprouts than about a month before fruit ripens I open trees up for light.

I've battled canker in my cherry orchard and it is not fun. We prune in late August to give time for the trees to heel. Our inital canker problem began when we pruned in late November. The trees are almost dormant at this time and the disease will spread by the first winter rains. I can see canker damage in the Spring, but the infection has occurred prior to that time. We don't prune in the spring.

I followed this thread on peaches hoping to be able to generalize to plums, especially my Italian Prune.

So: should I make that generalization, that late summer is probably a safe time to prune my prune here in Western Montana, or should I wait until late winter/early spring and prune when I prune my pomes?

Thanks.

I also have a question. Does this type of summer pruning or fall pruning apply to five to six year old trees as well?

We are talking about at least 5 or 6 year old trees that are already bearing. There is generally no reason to prune very young trees in summer beyond pinching shoots to direct growth. Dormant pruning doesn't slow the trees growth as much.

As far as fall pruning- this is usually reserved for hardiest species in Z6 or colder and after they are fully bearing. I would not advise fall pruning a plum tree in Montana although I can't speak from experience.

When I first started many years ago I consulted with a few commercial growers about the range of pruning times. That is when I learned that some growers prune their bearing apples after harvest but, as far as I know, no one around here prunes stone fruit structurally in the fall. They wait until after coldest weather of winter has passed and don't prune the stone fruit until older and then younger apples and then pears are done. That isn't to say that very early fall might not be OK- could be the growers are too busy harvesting apples then.

Keep in mind that Scott is in Z7 and he hasn't been doing this long enough to have had a test winter yet. Even with global warming there are going to be some very cold winters in the not too distant future, I bet. But if anyone wants to experiment, please let us all know the results.

I have pruned my 4 year old peach tree last spring and I had about 10% of my usual harvest. The tree got bad case of leaf curl, most leaves fell off and then the growth took off. It doubled over few months but very few fruits survived. I was thinking chainsaw. I wonder if I cut it back by one third and spray with bordeau/agri oil mix that it would save the tree. Maybe I should start new thread?

Here is a link that might be useful: Peach tree in spring