Need suggestions on trimming a Japanese Maple please

I bought this Japanese Maple early July 2013. After 9 months it has grown quite well I think. Brent (Evergreen Gardenworks), where I bought it, said to trim it in May, a little larger than it was when i bought it. It was about 12 inches above the pot when I bought it, and is now 32 inches above the pot. It was re-potted this past fall in a shallower but larger in diameter pot (as Brent suggested). Because of the unusual amount of snow and ice we got this winter, it has been kept on an unheated, sunny (closed in) back porch.
With all of the talented growers out there, I know you can, but would anybody make suggestions on how I should trim this up in May? Any help would be greatly appreciated. Because of the death of my brother (this past October), and lots of other things, I have kind of fallen away from the site, but I plan on making a come back. You people are a really big help to us who are new to bonsai. As you can see, its already starting to leaf out. Thanks alot!

I would begin by trimming back those long shoots from last season, leaving at least one set  of visible buds on each stem and maybe eliminate some - just fix the bones so that you have the skeleton of the tree you think you want. At any node, exercise the Noah's ark principle - only two - only two twigs emerge from any one node.

Then I would let it grow wildly until mid summer (June/July-ish) and would trim it like a hedge back to the shape of the canopy shape you want (I would actually use hedge sheers but it is the cutting, not the tool, that matters). It should backbud like crazy (or a crazily as your tree can) though it can take as long as 6-8 weeks for the new foliage to emerge on many Japanese maples, but it varies by cultivar. On a JM I am careful to leave a thin, airy canopy = fuel supply for the next round of leaf growth. I want it "thin" in the sense that I can see the interior of the tree so that sunlight can find its way in. I don't want it to be naked.

I again trim the bones within a few weeks after leaf fall OR leave it alone through the winter and trim the bones in the spring, at this same time, before the leaves emerge. I prefer one of these two times because the living cells distributed through the wood are metabolically active and perform their compartmentalization functions self-sealing the cuts. Some say it doesn't matter that this tissue is inactive during the dead of the winter because the pathogens at dormant too - maybe so. But to me it seems safer to do the orthopedic surgery at the edges of the dormancy period.

Osoyoung, thanks for the advice. I knew the long shoots had to come off, just wasn't sure where. You time frame of "letting it grow wild" matches that of Evergreen gardenworks too. Since I'm not going to trim it right this second, I would like to hear from others also. To see what kind of ideas I hear.
Thanks again.

Hi

I'm no expert and wouldn't want to pretend that I am but it seems to me that before you cut anything the first thing to do is decide what kind of future style you see for this tree.

How tall do want it to be? Are you planning to trunk chop it in the future or style it at it's current height? Which branches, if any, do you envisage using in the final design? Which might be used to further develop desirable features such as taper or conversely which might, if left, contribute to undesirable features such as inverse taper?

Presumably, if you want this maple to one day have a short, fat trunk with strong taper then your going to have to just let it grow wild for a few years and then trunk chop down low and regrow the top. In that case just feed well and leave everything. You'll be cutting almost all of it off eventually but in the short term the more branches/foliage you have the more growth/thickening you'll get.

On the other hand, if you want to make some initial styling decision now with the tree at it's current height I would think that the most important consideration should be addressing the relative lack of taper and the perfectly natural but unhelpful apical dominance.

I see there are several very thick and very dominant branches at the top of the tree. If it were mine I think that I would remove them completely. They're unlikely to play any part in the final design and if left will just continue to dominate at the expense of everything else.

Beyond that I would just let it grow out until early summer and then prune back hard at the top but less hard lower down.

To be fair this is essentially what Osoyoung was suggesting but I do think that it is important to prune differently on different parts of the tree.

Essentially, supress the strong growth at the top but encourage strong growth lower down. That should build taper and encourage back budding lower down which will eventually give you more branch options.

At least that's what I think but like I say, I'm no expert so I'm happy to be corrected by those more experienced.

Regards

Richard

Thanks for the feedback Richard. I am without a doubt, no expert. That is why I would like to hear from as many people as I can.

Morning to you. I'd strongly advise you to read "Refurbishing a Japanese Maple" by Walter Pall in the "Top Threads" section of this forum - it may give you everything you need to know. Of course there will be other opinions and methods than Walter's, but in my experience this will serve you well. Cheers.

Thanks Rick, I'll give it a look.

I think Harry Harrington's advice is also good ...

http://www.bonsai4me.com/Basics/Basics%20Bonsai%20Continual%20trimming.htm

Brett, thanks for the lead to the article, I read it , I appreciate it.

That's ok ... I'm no expert too, just passing along info I've read ...

Here's more :

http://www.bonsai4me.com/SpeciesGuide/AcerPalmatumAdvancedGuide.htm - "The guidelines on Trimming, Defoliation,Branch Pruning, Pinching Back, Internode Distances, Use of Sapdrawers and Positioning as all as equally applicable to Acer buegerianum as they are to Acer palmatum."

I also really like Peter Tea's bonsai articles, particularly his trident maple ones, with lots of pictures.  Here you can see pictures of a maple really left to grow ...

Yours still has a way to go, IMHO ... like I think it needs more developed branches in the lower part.  The lowest branch should be a good branch to keep and grow for helping increase taper.  The article below tells how Peter didn't like the skinny lower branches on his, so he repotted it in a bigger pot, and let it grow ...

http://peterteabonsai.wordpress.com/2013/08/13/the-trident-maple/

And at the bottom of the page below, all his trident maple articles.  Each one has some insights, even if the main topic is not what you are looking for, but one learns something from each.

http://peterteabonsai.wordpress.com/post-index/


I have another trident that just arrived from Japan, it was sent to me to practice grafting, this one has an even longer way to go.  I'll just let it grow wild for now ...

Picture right after it arrived this month from a 30-day sea voyage ... defoliated the pale leaves that grew in the dark.  I need long shoots like yours   

Thanks for all of the info Brett. I would love to have something shaped like the picture you included. When that branches out, it should be fantastic. I never run across anything like that.
Thanks again for the info.