pruning Chinese elm--when to stop before end of growing season/first frost

butlern

Shohin
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I have two Chinese elms that are constantly growing, summer heat of Oklahoma (7b), more recent cooler weather lately, doesn't matter. Grow, grow, grow.

Good signs, I think, and pretty standard for this species.

But, my questions pertains to getting ready for winter: should I stop pruning and just let them go (grow unchecked) as fall/winter approaches? I'm guessing the new growth should eventually be allowed to harden off, which will help strengthen and prepare roots (and the rest of the tree) for the coming winter, and the tree will stop pushing new growth on it's own as the growing season/daylight dwindles.

Average first frost (historic data) for this area is November 1st.

Any suggestions? Just let them go? Is now the time to stop pruning the elms in 7b with an average first frost of November 1st?

Clearly, I'm new to these endeavors (started this spring) and I have never over wintered trees. I just want to be sure I don't inadvertently encourage new growth (if it's ill advised) at the wrong time, as the end of the growing season approaches.

Thanks.

Noah
 

sorce

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I'd imagine you ought be done cutting, probly by Middle August.

Sorce
 

butlern

Shohin
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Roger that, Sorce.

Thank you, sir.

Pruning done!
 

erb.75

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ya, i'm not pruning any more here in Ohio. I stopped (and my trees slowed down their growth) right around sometime in mid-late august
 

Brian Van Fleet

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I backed off mine about a month ago. In the winter, I'll prune and wire.
Welcome to the Nuthouse.
 

butlern

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Yeah, ok thanks for the feedback... These trees are still going crazy... Which is why I was wondering if I could (should) still be training directional growth patterns.

We shall see what we have to work with this winter!
 

PierreR

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I backed off mine about a month ago. In the winter, I'll prune and wire.
Welcome to the Nuthouse.
Hi Brian, curious thought. In a climate as cold as our winters can be, in "winter" Id fear branches/twigs snapping if wired and bent at -40 (lower end of the chill...I hope ;) ) would you bring them in to warm up a tad? If the branches thaw, and hit the deep freeze again, would that be detrimental to the tree? When would someone in colder environments do this type of work? Late fall, very early spring?
Just thinking out loud. But your answers will likely prove useful in just a few short weeks!!
 

Brian Van Fleet

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I'm under the impression that living trees don't actually freeze (correct me if I'm wrong @0soyoung @garywood), and survive. The sugars in their systems function as antifreeze, so it's not like breaking an icicle. My climate is decent, but even if the soil is frozen, I don't have problems wiring most d-trees in the dead of winter.

The problem arises when you do crack a branch in winter, it has to survive until it can start growing again to begin forming callus tissue, which can be months and not always possible like a mid-summer snap.
 

klosi

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If you're winters are too cold, more then -9°C, then do the pruning and wiring in very late winter or very early spring. Just because the tree must survive the cold to start healing the cuts.
 

M. Frary

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If you're winters are too cold, more then -9°C, then do the pruning and wiring in very late winter or very early spring. Just because the tree must survive the cold to start healing the cuts.

That's when I do it.
 

rockm

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The issues with hard pruning as we head towards fall is die back of the new growth that is usually forced, as well as die back on the branch and/or other hardwood tissues that were cut. New growth on Chinese elm is inevitable if you prune now while the tree is in leaf. That means new soft growth will be killed off at the first hard freeze (the later you go with hard pruning in the fall, the bigger this problems becomes).

Additionally, you will get die back on the place you pruned during cold winters. Wounds may not have time to heal completely or effectively as cold weather sets in.

You can minimize both of those by saving all your hard pruning on deciduous trees until late winter. That puts the most active growth cycle just after the pruning. Also, a dormant tree isn't going to push new growth until spring. Waiting until late winter also shortens the time wound will be exposed to cold weather.

I prune and wire my elms, bald cypress, maples, etc. in February here in Zone 7 Va.
 
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Bunjeh

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I stop 60 days prior to what is anticipated to be a first frost so to give any new growth time lignify. So here,..last week of August'ish.
 

jk_lewis

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While I'm not in a really frigid part of the country, it does get down to single digit F temps here. I routinely do my major shaping-type (macroscopic) pruning after dormancy and leaf drop. That is the only time you can see the structure of the tree. I prune by degrees; not an entire branch at once, but over a period of 2-3 weeks. I see no evidence that the start of callusing is delayed by cold weather.

Growing season pruning is for "microscopic" pruning; tweaking twigs, pinching new growth, removing unwanted sprouts (lots of those).

I do not, however, have an abundance of elm bonsai.
 

rockm

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Not saying cold weather delays callusing--fall is the season where trees put on "wood." However, prolonged cold weather can damage fall-pruned limbs. I've seen it here in a number of species, including maple and especially Chinese elms here. Simply by waiting until February the danger is substantially reduced because there aren't four months of freezes left. you can see the twig structure just as easily in February as in November...
 
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PierreR

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I stop 60 days prior to what is anticipated to be a first frost so to give any new growth time lignify. So here,..last week of August'ish.
We will get our first frost tonight. 60 days prior puts me in mid July, with first buds in May... Late winter/ early spring it is.

Now that said, we could still get a few weeks of decent weather. I expect smaller bodies of water to freeze over by last week of October. Ground frozen by mid November. Ground here typically freezes solid 4 to 8 feet deep. More in some soils.
 

Bunjeh

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We will get our first frost tonight. 60 days prior puts me in mid July, with first buds in May... Late winter/ early spring it is.

Now that said, we could still get a few weeks of decent weather. I expect smaller bodies of water to freeze over by last week of October. Ground frozen by mid November. Ground here typically freezes solid 4 to 8 feet deep. More in some soils.
Please note that I am by no means an expert. I just have seen that late pruning can still promote budding and if the branch does not have sufficient time to harden off it can get damaged.
 

butlern

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Thanks, everyone.

I gather I should stop fertilizing, too, yeah?

I have been applying all purpose 3-1-2 weekly to one of the trees since I acquired it in June, and to the other when I acquired it in August.
 

Tibar96

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It's my first time wintering bonsai since I started last spring and I think I made a mistake and pruned and wired all the branches on my little chinese elm now, in late december.... what do you advise me to do next? The tree lost it's leaves naturally so it's dormant. I live in romania(zone 6) but this year we have a pretty warm winter (over 5 C during the day and about freezing at night)
 

Paradox

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It's my first time wintering bonsai since I started last spring and I think I made a mistake and pruned and wired all the branches on my little chinese elm now, in late december.... what do you advise me to do next? The tree lost it's leaves naturally so it's dormant. I live in romania(zone 6) but this year we have a pretty warm winter (over 5 C during the day and about freezing at night)

Give it proper winter protection but keep it cold enough to remain dormant
Keep an eye on it and water it when the soil starts to get dry. If the soil is frozen, you dont need to water.
Wait for spring
 
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