When do you do your winter pruning ?

[davetree]

I am sure this has been asked, but I would like to know when you do your winter pruning. I know that in a warmer climate than mine you can prune anytime. I am talking about deciduous trees. I always do my pruning in late winter, never early or middle. The reason is to prevent dieback of twigs or trunk in my cold weather. Are there species more vulnerable to this than others ? When do you winter prune, on what species, and what kind of pruning ? Thanks for your replies.

 

[JudyB]

Well, as you know, I do most of my D trees in early winter. ( pines - I only have a few) Especially Bald Cypress, and anything that is safe (not prone to dieback) and takes a long time for branches to set. As I like to take the wire off sooner than later with varieties that grow quickly in the spring, then I don't have to worry about wire cutting in on the spring flush.

I would appreciate others answers on this, as I've seen varying tactics discussed, and am not sure that my approach is the correct one.

 

[0soyoung]

I don't think die back has anything to do with temperature or the time of year.

I've been doing air-layers, some of which didn't develop roots and stayed on the trees for multiple seasons. They have focussed my attention on the mystery of what triggers/causes die back - it isn't the temperature or the season.

I had a layer on a Shishigashira JM that went through the winter of 2011 clad in damp sphagnum wrapped in plastic. Die back occurred below the girdle June 2012 (another layer on the same tree and a similar sized branch survived to be successfully harvested in Aug 2012). I have twice (once in the 2010 season and again in 2012) tried to layer several branches of my Higasayama JM. All 5 of them suffered die back below the girdle in the same season.

Just last month I had a layer on an Aka Shigatatsu sawa JM die because of the same die back below the girdle - the layer was made in the 2010 season and never produced roots, but remained clad in plastic wrapped damp sphagnum the whole time. Yet I've still got several stubs on this same tree from winter pruning one or two seasons ago that have yet to die back. These have been open to the air the whole time.

Lastly, I've had a similar failure of Hornbeam air-layer, so this isn't a JM phenomenon.

So back directly to your question: I do winter pruning when it is convenient and see no evidence that pruning at any particular time is more prone to die back than any other. I only winter prune deciduous trees for structure. Otherwise I only prune during the growing season. Obviously I am very JM-centric, but not exclusively.

 

[bonsaibp]

I am sure this has been asked, but I would like to know when you do your winter pruning. I know that in a warmer climate than mine you can prune anytime. I am talking about deciduous trees. I always do my pruning in late winter, never early or middle. The reason is to prevent dieback of twigs or trunk in my cold weather. Are there species more vulnerable to this than others ? When do you winter prune, on what species, and what kind of pruning ? Thanks for your replies.

I've been pruning and repotting deciduous tree for a few weeks now, but I'm in Los Angeles and we don't really get much of a winter. Also it's been raining so I have time to pot.

 

[GO-OK]

In mid-late fall deciduous trees can still compartmentalize and start the wound healing process immediately after leaves turn color or drop entirely. I try to prune or wire just after leaf drop. In fact, as soon as peak fall color is reached I strip leaves and start some pruning and or wiring.

I have wired with no problems mid winter or late winter.

I don't think it matters much. It may only matter based upon how you store your trees in winter. If you keep them in a very cold environment dieback maybe a problem.

An unheated garage around 35-40F poses no problems.

 

[JudyB]

. I try to prune or wire just after leaf drop. In fact, as soon as peak fall color is reached I strip leaves and start some pruning and or wiring.

Do you ever experience the trees putting on new growth after you do this directly after leaf drop? I find that it can stimulate new growth to do pruning in the fall, and I've heard others say the same thing. Which could cause problems if the new growth isn't hardened off before winter.

 

[davetree]

Well I am asking about cold environments where it will freeze after pruning or wiring. Anybody avoid winter pruning or wiring if your trees are going to freeze ? 3 degrees here and the garage is at 28.

 

[painter]

this is the first year i have trimmed soon after leaf drop , on one japanese maple in the ground and others that are in pots in my unheated garage. if you post again in spring i will let you know how they did. it was an experiment for me. this season i wanted to see the effects. although critters like squirrels ate the remaining buds on the japanese maples in the ground, so that may be another element i need to consider in the outcome of die back. damn rats
p

 

[edprocoat]

Davetree, I usually try to do my winter pruning during the winter and my summer pruning during the summer.
Actually I am kind of in a perpetual summer situation going to Fl. for the winter months so my trees get a couple of months of cold (sometimes).

I have to ask though, I was under the impression that Minnesota had four seasons, Winter, Hard winter, Arctic winter, and what the rest of us would call "Autumn" , so when do you do your summer pruning...

ed

 

[crust]

Based on talking and observing others but mostly on observing my cold hardy native trees, I Think winter die back due to a timing issue is a non-problem on fully dormant trees. I just have not seen any differences. Temperate trees not fully dormant being kept in mild places ( like Japan or Portland) can actually be more physiologically active than commonly thought--reactions may happen--perhaps this is where this rule work in late winter/early spring evolved from.

I have been experimenting with winter work on my trees the last couple of years and have had good success. I wire, cut, carve, whatever. I have to. I simply have more time in the winter and at least these things get done--and the trees improve.

Some time ago I asked my friend Lenz, "how did you take care of all those seasonal driven chores--like in spring (wiring re-potting etc.) on so many trees? He said, " I worked all seasons, all the time on some, trimmed all the time on some, wired all the time on some, repotted some in the spring, some in the late summer(juniper), some in late winter even (larch) only to be put away again"-- Of course all of this with came with random caveats and warnings.

I have notice the Europeans routinely have work shops during odd seasons I have always been told are wrong yet they do major work then. I have talked to and read about Japanese located bonsai apprentices about seasonal work and very often the overwhelming amount of work to do means procedures are simplified such as staged candle plucking--they get done all at once--blam--because there is no time to stage them all, or done when convenient, or when there is time. I was surprised at all they did in the winter.

I have no JM or anything like that and don't clearly know all the hormonal issues involved but I have come to the personal conclusion that if a tree is profoundly dormant and kept at reasonably moderated cold, protected environment, routine thinning and cutting back is not a problem in winter.

 

[Dav4]

I don't have enough deciduous trees to reply with confidence, but I've always wondered about timing on pruning maples during dormancy. I've got several very large trident stumps in the nebari building Phase- read that as "I should have done the nebari work while the tree was growing out, and now I've had to start from scratch with ground layering". Anyway, they've got 3-4 foot branches that need to be cut back. It was 25F this AM, the trees are left outside here year round and we'll have periodic sub freezing weather here(potentially single digits) for at least 8 more weeks. I'll cut them back to 1 foot lengths, just above a bud...we'll see what happens.

 

[Poink88]

I work on my trees (prune, repot, etc.) year round partly because of where I am.

Re: when I do winter pruning, I tend to think that I should do it late winter (very relative time wise)...again due to where I am since the hotter days coupled with early pruning triggers early sprouting of buds. Note that here, (late winter and) spring comes earlier than elsewhere too...around mid-January, buds already start breaking.

This is only my 2nd winter doing bonsai so not totally sure yet.

 

[ghues]

Just a thought........for deciduous.....in winter the sap is not flowing (tree is dormant?) therefore healing of the cut surface will not start until later winter (where I live) or early spring. This cut surface could be a point of infection? I do my major prunning in late winter so that I can remove the winter kill (cold temps and wind) at the same time.
Like all things bonsai its location location location...
Cheers
G

 

[GO-OK]

Once leaves start to drop they are dormant. When in fall color the tree can be stripped of leaves and pruned without stimulating a growth response. BUT...the tree is still physiologically active. They will compartmentalize and the healing process will begin.

Sam principle applies to wiring after leaf drop. I prefer wiring in fall because 1) all branches are visible and no need to be careful of leaves and no need to defoliate. 2) Its just easier 3) Branches will set by mid March. I can remove the wire and do it again in early summer if I want to defoliate. Fall wiring may help you develop the tree faster depending upon the species. Elms come to mind as a great tree to do fall wiring, then an early summer wiring.

That said..use cut paste to avoid pathogens and drying out near the pruning scar.

 

[lordy]

I learned from the guys who run the National Arb. bonsai museum. They suggested waiting until well after the freeze has occurred and then leave a good long stub to be removed later. If you cut too close to the part you want to keep, there is a possibility that it will die back. If you leave a good stub, the stub is what shrivels back to the part you want to keep. I wait unitl about the middle of February in central Maryland. Works for me.

 

[ghues]

Once leaves start to drop they are dormant. When in fall color the tree can be stripped of leaves and pruned without stimulating a growth response. BUT...the tree is still physiologically active. They will compartmentalize and the healing process will begin.

Sam principle applies to wiring after leaf drop. I prefer wiring in fall because 1) all branches are visible and no need to be careful of leaves and no need to defoliate. 2) Its just easier 3) Branches will set by mid March. I can remove the wire and do it again in early summer if I want to defoliate. Fall wiring may help you develop the tree faster depending upon the species. Elms come to mind as a great tree to do fall wiring, then an early summer wiring.

That said..use cut paste to avoid pathogens and drying out near the pruning scar.

I'll have to caution folks on your comments "Once leaves start to drop they are dormant".... if you study dormancy you'll note that there are two kinds depending on a number of factors....it also depends on species, climate and such.... but I do agree that styling when branches are still flexible is a rational approach... as long as you can follow it up and get the wire off before wire scarring.....as some of the maples can put on a lot of growth early....
Cheers

 

[GO-OK]

Fall dormancy is primarily caused by 1 main factor. Day length. Once that occurs and temps drop, leaves begin to turn and then fall.......the tree will not be awakening until a minimum period of days has elapsed...and temps then rise sufficiently.

Pruning & wiring a Maple or Elm in the midwest in late October-Mid November is pretty darn safe.

I've never seen a trident or palmatum or elm push new growth after fall leaves have dropped and they've entered winter dormancy.

 

[crust]

Fall dormancy is primarily caused by 1 main factor. Day length. Once that occurs and temps drop, leaves begin to turn and then fall.......the tree will not be awakening until a minimum period of days has elapsed...and temps then rise sufficiently.

Pruning & wiring a Maple or Elm in the midwest in late October-Mid November is pretty darn safe.

I've never seen a trident or palmatum or elm push new growth after fall leaves have dropped and they've entered winter dormancy.

As of late I have heard and read interesting revelations about dormancy that are accepted modern science. Check out Crataegus WS or talk to the director at Weyerhaeuser. Apparently trees dormancy is staged and and is localized to its different parts i.e. trunk, roots, branches. It is dependent on numerous factors such as light, temp, genes and can be partial to one zone relative to these factors. Just having leaf drop does not mean a tree is fully dormant.

 

[GO-OK]

Crust,
Not disagreeing ....Just going by my personal experience. True roots etc continue to grow, but this doesnt mean its unsafe to prune and wire a deciduous tree in fall or winter. As I said earlier, if you prune after leaf drop the tree is still active and able to compartmentalize the wound....it just "should not" push new growth as a result of the pruning. But I amonly the "director" of my collection.

When I call the director to confirm their findings...should I tell them "you said that they said"......?

Just kidding, arguments by authority are always a great way to make a point.

 

[Mac In Oak Ridge]

Once leaves start to drop they are dormant. When in fall color the tree can be stripped of leaves and pruned without stimulating a growth response. BUT...the tree is still physiologically active. They will compartmentalize and the healing process will begin.

Sam principle applies to wiring after leaf drop. I prefer wiring in fall because 1) all branches are visible and no need to be careful of leaves and no need to defoliate. 2) Its just easier 3) Branches will set by mid March. I can remove the wire and do it again in early summer if I want to defoliate. Fall wiring may help you develop the tree faster depending upon the species. Elms come to mind as a great tree to do fall wiring, then an early summer wiring.

That said..use cut paste to avoid pathogens and drying out near the pruning scar.

Several articles written by Japanese bonsai masters that work with Japanese Maples direct that you cut back Japanese Maples 7-10 after leaf drop. Their justification is that the sap has dropped from the limbs and won't bleed. Not bleeding keeps the nutrients inside the tree until spring, instead of leaking out and running down the trunk. They also state that the tree will start the healing of the cut and come spring it will be sealed sufficiently not to leak then also. I use cut paste on the cut back surfaces. Leave a stub of varying length depending on the diameter of the cut off limb.