Bonsai Study Group Forum

Species Specific => Japanese Maple Bonsai Discussion => Topic started by: nathanbs on September 26, 2011, 09:24 PM

Title: hard prunining Japanese Green Maple
Post by: nathanbs on September 26, 2011, 09:24 PM
When is the best time of year to hard prune a Japanese green maple? I mean trunk chop the heck out of a 8' tall tree that has nearly a 4" diameter trunk where i want to cut it?
Title: Re: hard prunining Japanese Green Maple
Post by: Alain Bertrand on September 27, 2011, 01:54 AM
I do that at the beginning of summer because at the end of winter trees bleed so much though it seems not to kill them.
I have been told that cutting just after leave fall is OK too but I have not tried it myself on big chops.
Title: Re: hard prunining Japanese Green Maple
Post by: John Kirby on September 27, 2011, 04:15 AM
I agree with Alain's suggestion. I have cut them really hard in the fall when we have dug them and barerooted them at the same time (then protect from  below 20 f temps). If you seal the big cuts, clean the tools with alchohl between trees, it works pretty well.

Good luck,
John
Title: Re: hard prunining Japanese Green Maple
Post by: nathanbs on September 27, 2011, 11:18 PM
i read i dont know where that contrary to what most people think it is actually better not to prune in fall it is better to prune when the tree is active so it can start healing immediately. I specifically remember the author saying he marked branches to be removed with red paint and waited until the tree was actively growing and peeked into the tree to find the red marks and removed those branches. Any opinions on this? Keep in mind that i have no need to root prune at this time if that makes any difference one way or the other. Should i take this opportunity to root prune or wait until major scars have healed than focus on roots?
Title: Re: hard prunining Japanese Green Maple
Post by: Alain Bertrand on September 28, 2011, 01:35 AM
I have cut them really hard in the fall when we have dug them and barerooted them at the same time (then protect from  below 20 f temps).
Rempoted mapples don't bleed much anyway. If someone has experience of big chops in the fall* without any work on the roots, I'd be happy to hear about it.

*It would fit more easily in my work schedule.
Title: Re: hard prunining Japanese Green Maple
Post by: Owen Reich on September 28, 2011, 10:29 AM
I have done major surgery on trident and Japanese maples in Fall and Spring.  I did major root work in the Fall as they were usually big landscape trees that were ripped out balled and burlaped or just plain ripped out of the landscape.  Tridents are a lot more forgiving to the ordeal.  I have successfully done major cuts on Japanese maple in spring just before the buds were really swollen but not open in Tennessee.  The trees did bleed but I covered with cut paste and by reducing water (as the tree was a great deal smaller after the cut, the paste rose a little but settled after a few days.  I have cut Japanese maples in bonsai pots before too in spring with similar results; all successful.  Sap bled but only for a short time.  I imagine a tree that big has a big root system in tow.  Leaving a big root system in spring is dangerous as it's the equivalent of hooking a fire hydrant to a garden hose.  The turgor pressure from a big root system with an unbalanced top is no good.  Big cuts in the Fall (after leaf drop) without root work should be no problem as long as root reduction is done in the early spring following.  I have never done this.  I agree with John on protection during winter from deep freezes.     
Title: Re: hard prunining Japanese Green Maple
Post by: nathanbs on September 28, 2011, 11:49 AM
So what does everyone think is the best option considering this tree ultimately needs a major reduction in both its branches and its roots. Time is of no real concern to me. The health of the tree is my primary concern, well besides the fact that i ultimately want to make a bonsai out of a small to medium sized tree. If the tree had its way it would be planted into the ground.
Title: Re: hard prunining Japanese Green Maple
Post by: rockm on September 29, 2011, 11:16 AM
I'd do it in the spring. Hard pruning in the fall CAN set off a flush of new growth that is very vulnerable to winter kill. Waiting until after leaf drop can help with that, although I've found that cut branches can get die back in winter after such treatment. It can depend greatly on how the tree is stored for the winter.

In spring, the plant is set to recover more quickly from hard pruning. It doesn't sit around for months with a pruing wound that doens't heal. I've routinely root pruned and topped Japanses maples aggressively in the spring.  I've reduced root masses by 90 percent and trunk chopped the tops drastically in late April or early May. The maples have routinely throw out huge masses of new growth afterwards.

Trees can't really "bleed to death," but the sap flow can be alarming visually. To reduce it, cut the roots an hour or so prior to top pruning or trunk chopping.
Title: Re: hard prunining Japanese Green Maple
Post by: John Kirby on September 29, 2011, 04:18 PM
When someone tells me that they need to cut down a tall japanese maple "with a trunk chop" and they don't need to do root work, I think they haven't thought through the priorities of tree development. Getting the Nebari right is critical in maple development, we can get away with bad roots on Junipers and OK roots on pines, but maple have to have a good nebari. Or instead of "chopping" why not airlayer the top and a few sections below, then work the roots after the trees are separated.
Title: Re: hard prunining Japanese Green Maple
Post by: Alain Bertrand on September 29, 2011, 06:06 PM
Well, I can feel concerned by your reflexion ;)

I have mapple (trident, palmatum) both in pots and in the ground. I don't root work those who are in the ground because   if I 'd transplanted them every two or tree years, they would grow jjust a little faster (if any faster) than those in a pot.
I already lifted  some of these mapple out of the ground and layered them (with various success  ;D) and I plan to follow with root graft. Those trees have big trunk but their nebari is immature, and will stay so for a while  even if layering is successful.

This is just that growing good bonsai takes time and that there is no short cut no side effect.
Title: Re: hard prunining Japanese Green Maple
Post by: John Kirby on September 29, 2011, 09:14 PM
Alain, many of us have trees that we put into big pots or into the ground to grow trunks. Typically, we (generally speaking) don't do the preliminary root work to get rid of the tap root and develop a good radial nebari that is well spaced and developed. Gary wood shows some nice development work on his blog, the Ebihara trees were spectacular and Boon discusses how to develop good nebari and lower trunk in his Maple DVD's.

My own experience i that it takes a lot longer to deal with repairing a mediocre nebari than it does to do the work up front. Not saying one is right and one is wrong (though others might).

John
Title: Re: hard prunining Japanese Green Maple
Post by: bwaynef on September 29, 2011, 10:18 PM
Typically, we (generally speaking) don't do the preliminary root work to get rid of the tap root and develop a good radial nebari that is well spaced and developed.


Emphasis mine.  Is that a typo?
Title: Re: hard prunining Japanese Green Maple
Post by: John Kirby on September 30, 2011, 06:38 AM
No, while we should do the root development work up front, most of us have historically not done this well. I am as guilty as anyone, it is so much easier to just do it right up front, even though it will "slow" down the initial planting and trunk growth- in the end you are much better off by doing it correctly.

John
Title: Re: hard prunining Japanese Green Maple
Post by: bwaynef on September 30, 2011, 08:34 AM
Thanks John.  I follow you now.

I can't say from experience that doing the work ahead of time is faster than fixing it later, ...but I'll attest to doing it right the first time sure does take a while.  (I'm talking specifically about building nebari on a maple ...but I guess there's a fair amount of carry over to a lot of things in life.)
Title: Re: hard prunining Japanese Green Maple
Post by: nathanbs on September 30, 2011, 09:52 AM
considering i am going to have one or more huge scars, is there any possibility of not touching roots at this time? I dont disagree that roots are as important as branches, but you will not see the scar from the tap root as it heals or if it never heals perfectly. I know that you can prune a tree planted in the ground pretty severely so why not one in a 24" box?
Title: Re: hard prunining Japanese Green Maple
Post by: John Kirby on September 30, 2011, 10:49 AM
Honestly, you can do whatever you like, but you asked, you got an answer. I look forward to following how the tree develops over time. Please post some pictures to chronicle the adventure.
Title: Re: hard prunining Japanese Green Maple
Post by: nathanbs on September 30, 2011, 12:49 PM
im not looking to do whatever i like, im looking to do what makes the most sense considering all of the elements involved. I have logic and common sense but what i dont have is the experience. My logic and common sense tell me that the single biggest hurdle will be healing a 4" scar. Growing branches and roots are second to that because if i cant get a successful healing of that scar whats the point. Im in no hurry and that was my comment about the roots. "I dont need to worry about the roots now if i dont have to" was meant to address the health of the tree not the future nebari. The one great point besides helping me decide when is the right time of year was to look into the tree for possible air-layer opportunities that i did not consider doing.
Title: Re: hard prunining Japanese Green Maple
Post by: Chrisl on October 01, 2011, 02:22 PM
In Boons maple dvds, he does a pretty big prune on a maple after the leaves have changed.  But, it's only a 'partial hard prune' leaving some of the tree's branches to finish the 'hard prune' the following year from what I recall. 
Title: Re: hard prunining Japanese Green Maple
Post by: AlexV on October 01, 2011, 11:04 PM
Healing the big scar may seem like the biggest hurdle, but in the long run you will find it is easy compared to creating a proper nebari.  That is what John is saying.  The worst scars can be healed in a few years, but the longer you wait to deal with the nebari the worse it will be.  This is what I have been told by many people who have grown out a lot of maples (or any tree really), and now kick themselves for worrying about scars and branches and ignored the roots.  In a maple, you can have the best branching and zero scars, and if your nebari is not good, the tree will not look good.  You might get lucky with your roots, but chances are they will be the factor that becomes the most time consuming in creating a quality tree.

Having heard this, and being young and enjoy growing trees out, I have been following the scheme below, and I will be ready to pull my first experiments out of the ground in a couple years.

Year 1 - Repot when buds swell and move from 2" or 4" pot to 2gal pot.  Root prune to get radial roots, then make a mound of soil in the pot, and plant so the roots make a nice shape moving slightly downwards.  I have been getting starter trees from Brent at Evergreengardenworks, and have been really pleased, he cuts the tap roots so they already have radial growth and require very little work.  When they start to push new growth, I wire the branches for shape of the future trunk.

Year 2 - Repot when buds swell and check the roots, make any corrections needed.  Yes this slows down growth, but i am not worried about growth yet, I am worried about shape, growth will come later.  When they shoot out new growth wire the secondary branches for shape.

Year 3 - You now have a tiny plant with good starter roots and trunk movement, plant it in the ground until the trunk swells to the size you want.  I plant mine onto a board or tile to make sure the roots keep moving outwards and not down.

Again, I do this ahead of time because the nebari is so important on deciduous trees, and it will be the biggest time sink later on if not dealt with early.  I will post some pictures when i finally pull something out of the ground, but this is the advice I have gotten from the people (including John, Boon, Jim Gremmel etc etc) who grow trees that I want.  Best advice, find someone who's trees blow you away, and follow their advice, even if it seems counter intuitive. 

Good luck!
Alex
Title: Re: hard prunining Japanese Green Maple
Post by: cbobgo on October 01, 2011, 11:35 PM
to answer your original question, what time of year should you do the cut - you live in southern california, so the timing is not as critical as folks in harsher climates.  You could pretty much do it at any time, and your tree will be fine.  The only thing I would advise against is doing it during early spring growth when the sap is really flowing.  Any other time of year should be OK for you.

- bob
Title: Re: hard prunining Japanese Green Maple
Post by: nathanbs on October 02, 2011, 04:03 PM
thank you for all your advice.
@Alex, i hate to burst your bubble but unless you are growing mame or shohin trees, those branches that you are grooming on your seedlings will be cut off in the future as they likely will have gotten too thick by the time you have developed a nice size trunk. I think your focus on roots and trunk movement is great but i think you should probably let the majority if not all of the foliage grow unchecked to help fatten up the trunk and roots.
And to be honest im not sure every tree can make a perfect bonsai within my lifetime, so with that said i prefer no scars or very nicely healed scars over great nebari anyday. I would love to have all the above but its not always acheivable or atleast not within some reason.
I figure that if i can develope a trunk worthy of working on its branches and roots, I will put in the years to do so. Versus having beautiful roots and branches on a terrible trunk.
Title: Re: hard prunining Japanese Green Maple
Post by: John Kirby on October 02, 2011, 04:26 PM
I can't wait! Please post pictures.
Title: Re: hard prunining Japanese Green Maple
Post by: scottroxburgh on October 04, 2011, 05:24 AM
Can't wait to see pics...

I'd repot first, to get it into the soil you know (watering etc), and working the roots.

Answering the question...
Japanese maples - In mid fall, I'd chop to the lowest growth then progressively shorten over the next few years.
Trident maples - Chop where you want.

But as many others have said, do the root first.
Title: Re: hard prunining Japanese Green Maple
Post by: bkelley on July 22, 2012, 11:06 PM
I agree with Alex.  Nebari on maple very important.  I recently grew some hedge maples and Japanese maples from seed and took the time to work the roots properly, removing the tap and spreading out the radial roots, with good results.  You can then grow on and develop your trunk to size you want, best to probably let everything grow unchecked in order to build trunk girth if going for a bigger tree. 
Timing pruning matters as to what type of growth you want afterwards.  In late spring early summer after the tree has built up a good head of steam, you can prune and get an explosion of growth with plenty of options for branches, new trunk lines etc.  This is good to do when you want a lot of bud activity.  I just did this with a couple trees with great effect.  I let the tree grow unchecked during spring and then when you cut all of the energy that was being put into above where you make the cut has to go somewhere. 
Eliminating branches is best done in fall.  You won't stimulate a lot of new growth.  Energy will go to all existing buds.  Pruning for structure and refinement is good in spring.   
In any case as with most things bonsai, timing is important and objectives are important...like someone asked size and type of image you are going for, style etc. Peter Adams book on maples is great and working with Colin Lewis has been great.