Pruning practices after a potentially damaging winter

Winter is finally lessening its grip here and we’re supposed to see a warmup starting on Saturday. It hit -3F here this winter, so not as bad as last year’s -5F but still cold. I grow a few varieties of Asian persimmons and I’m wondering which of them were damaged. Last year resulted in tip damage only to Jiro, Ichi-ki-kei-jiro, and Saijo, while Great Wall was left unscathed and set a great crop (for a young tree).

I’d like prune some of the trees as they got a little shrubby (that’s a technical term :smile: ) but want to assess damage first. If it’s not readily apparent, is it okay to prune after the trees begin to leaf out? If I do that, should I allow them to push out their full first flush before pruning out some growth? From what I’ve read, the tree is basically running on reserve energy until it pushes out a number of leaves (at least in apples). After that, the new growth begins to put some energy back into the system. I wonder if by pruning just as the tree begins to push out, in order to see damage, I’d be doing more harm than good. Thoughts?

Scratch-test the areas that concern you. If you want to prune to discourage the scrubby growth, do so before new growth.

I lost everything above ground on my Ichi after last winter, but the roots sent up new growth like gangbusters. I think I’d rather have one of the hybrids or Szukis than fight winter with another Asian variety.

I planted an American variety, Elmo, at a friend’s house and it had no problems with the winter last year. Hopefully I will get fruit this year off do it

~Chills

The scratch test is a good one, however I’m more concerned that some of the mixed buds toward the end of the branch got toasted. My understanding of persimmons is that they bear fruit from mixed buds toward the end of the branch. Not sure how to test those buds other than to dissect one.

Technically, trained arborists would say that a tree is more prepared to deal with wounds either when it is dormant or a couple weeks after it has fully leafed out and energy reserves have returned. Alex Shigo observed that wounds are slowest to close when trees are leafing out and when trees are beginning to harden off for winter, as I recall. Other researchers suggest that the slower closing of the wounds usually poses no problems to a tree.

And yet, for peaches, wounds are said to close quickest and resist canker best if they are pruned sometime between first growth and bloom- no mention is made that this might be deinvigortating for a young tree you are still trying to size up or that the depleted state of energy reserves delay healing and it would be better to wait 3 or 4 weeks after bloom.

I suspect for your persimmons and most trees in general, time of pruning would barely make a noticeable difference in terms of ultimate growth the following season. This may be why the most experienced growers often say the time to prune is when the pruners are sharp.

I will say that old apples trees that I manage entirely with summer pruning do lose significant vigor over time (usually a good thing) if my observations have significance.

Pruning a few branches form your own trees should be fine, whenever you do it, however.

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Thanks Alan, I appreciate the expertise. I went out today and didn’t note any obviously damaged wood or buds, so that’s encouraging. If the trees can get through one more night of single digits then I think we may be in the clear. I think I will begin pruning mid-March here and perhaps dissect some buds then to attempt to assess damage.

Will be another good year to test hardiness, that’s for sure!