Waterfall maple -- prune central branch?

Discussion in 'Maples' started by MapleZen, Jun 11, 2022.

  1. MapleZen

    MapleZen Active Member

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    I have an in-ground Waterfall that I've neglected to prune properly and am coming to the task several years too late. It has been planted for ~8 years.

    My general practice is to never let weeping maples branch off into three directions at the same time. In this instance, three equal branches depart from the main trunk. I need to prune one of them because of the way the tree is growing onto my patio (see photo). This would result in multiple pruning "violations":

    a) would be pruning a branch the same diameter as the main trunk
    b) would be removing ~33% of the canopy in a single cut

    Should this wait until all the leaves are off and the plant is dormant, or could it be done now? Would you apply wound paste to such a large cut? Any other considerations?
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  2. Acerholic

    Acerholic Paragon of Plants Forums Moderator VCBF Cherry Scout Maple Society

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    Good afternoon @MapleZen, I would never carry out such a large cut at this time of the year. This I would leave until dormancy. I only do slight thinning in Summer. The 33% rule is a good one as it does not shock the tree too much, this can be done now to let light and air into the tree.
    I don't apply wound paste, but I know others do. So it's a personal thing. I like the tree to heal naturally.
    So my thoughts for your tree, is to thin out a little now and carry out the major prune when it's dormant.
     
  3. emery

    emery Renowned Contributor Maple Society 10 Years

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    Hi, I'd wait for early autumn also. I don't think there's a problem removing a limb this size.

    On the subject of paste or other sealant, I'm not a fan. But we (the general we!) tend to forget about a guy named Alex Shigo,

    Alex Shigo - Wikipedia

    He was the Chief Scientist for the US forest service for a long time, studied plant pathology, and essentially changed the way we think about trees healing. Worth reading what he had to say.

    As far as I know Shigo never did bonsai, so maybe that has something to do with his views!
     
  4. MapleZen

    MapleZen Active Member

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    Thanks! I never use wound paste, but have never made a cut this sizable in a tree of this age before. The impatient part of me wants to get it over with now, but I'll wait until October or so.
     
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  5. 0soyoung

    0soyoung Rising Contributor

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    I would do the opposite = do it now.

    Presently the tree is active, meaning they are doing all those things that trees do. If you cut now or anytime the tree is active, signaling to compartmentalize damage happens immediately. Exposed cambium desiccates (as it would in any time of year) until a new epidermis is formed, after which it resumes growing according to the new auxin gradients. That is it forms new phloem tubes that follow a path around the wound = regrowth over the wound often called 'healing'. Waiting until the tree is less active, just prolongs the CODIT process.

    On the other hand, I generally do wait until immediately after leaf-drop or as buds swell in spring to do structural pruning for the simple reason that I cannot clearly see what I'm doing when it is in leaf. I could defoliate the tree to do it during the season, but this is tedious and time-consuming PLUS it eliminates a lager part of the growing season waiting for a new flush of foliage. Cutting in fall can lead to some die-back over winter, but that can be cleaned up in spring before bud-break.

    The issue of visibility is the only reason, IMHO, to not remove branches (or to not 'chop' a trunk to start a bonsai) now, during the growing season. In this specific case, there is no problem with visibility.
     
    Last edited: Jun 11, 2022
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  6. emery

    emery Renowned Contributor Maple Society 10 Years

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    I don't know of any argument that can counter these points. The usual one is "fear of disease", but actually chances of disease are much higher in fall/winter I believe (see, when to prune plums and cherries). One-time excellent contributor John @JT1 often espoused the view that pruning is best done after the first flush, that is mid-June for most of us.

    It's hard to tell the diameter of the stems in the picture. But one thing we often suggest is "leaving a stub" so that the twig can die back completely before being cut at the collar. I felt that the stem in question looks thin enough to justify that approach, and it does seem to me that it would be better done with the sap fallen, for faster drying.

    None the less, and as you say, I do most pruning in autumn and early winter because 1) you can see what you're doing, 2) it's a much less busy time of the garden year than now, 3) burning is authorized (it is still, but that won't be the case for long).
     
    Last edited: Jun 13, 2022
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  7. MapleZen

    MapleZen Active Member

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    Wow -- two very compelling and completely conflicting pieces of advice. The branch in question is ~5-6 inches in diameter, if that makes any difference.
     
  8. 0soyoung

    0soyoung Rising Contributor

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    I might believe circumference, but not caliper.
    Regardless, my advice remains the same.

    You may want to view module 3 of this video course before you attack it.

    The whole course is quite worthwhile, IMHO.
    When you have time
     
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  9. MapleZen

    MapleZen Active Member

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    Yes, sorry! Not diameter, circumference. Will watch the video, thanks again!
     
  10. emery

    emery Renowned Contributor Maple Society 10 Years

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    Nice series of lectures, I wonder if the link is in the forum resources?

    That's still a relatively large branch, but I guess I'd go ahead and cut to the collar now; it's still early enough that you should get some compensatory growth from the other sides, and it should have a chance to ripen before winter. From my point of view, if I'm dealing with it, I'd rather deal and have it done rather than forget about it later, if you see what I mean!
     
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  11. MapleZen

    MapleZen Active Member

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    The deed is done. Went through many of the pruning videos above beforehand. Very informative although didn't really answer the June vs October large prune debate. I think a did a good job with a hand saw although there's a slightly feathered edge remaining that I'm considering sanding (see pic). Sprayed the wound with Bourdeaux as there's a little powdery mildew popping up on some of the leaves -- not sure if that will do anything, but we'll see.

    Already the tree structure is much improved and immediately apparent the tree has a nice form that will emerge over time. This just reinforces my idea (probably read it somewhere, but can't for the life of me find it now) that a weeping maple should never, at any point, be allowed to branch in three directions at once.

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  12. ROEBUK

    ROEBUK Contributor Maple Society 10 Years

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    Prune mine whenever they look unkept and untidy , can't stand scraggy looking trees !!! Started last week with a few but had to contend with the ridiculous windy weather , so only managed a few but better weather for this week though :):) Wakehurst Pink which needed bringing back into line, was getting way to big so trimmed it off to a more pleasing shape. Do quite a few during June then once the leaf drop is over major branch removal is done . Have done this for decades now and never had any problems. Finally Mikawa yatsabusa again from this month, inner pruned to get those main leader branches moving more , plus getting a good air and light distribution as well now , before and after pics.
     

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  13. Acerholic

    Acerholic Paragon of Plants Forums Moderator VCBF Cherry Scout Maple Society

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    Very tidy M, I have started my Summer thinning and tidying. Probably a week ahead of you here down South.
    That's my method aswell. Major branch removal in dormancy.
     
  14. ROEBUK

    ROEBUK Contributor Maple Society 10 Years

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    Sekka Yatsabusa just had a slight trim this morning making it look a bit neater. Must admit all the ground trees have put on some serious growth this year , think they are trying to catch up on last years debacle !!!
     

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