sick green Japanese maple?

[Skye325]

I am going to Bonsai this Japanese maple but wanted to know if anyone new why the bark was coming off and some of the branches are white. I bought it this knowing there might be a problem but it was a great deal. I am also receptive to advice on how to cut it.
Thanks!

 

[0soyoung]

Several years ago, it got seriously desiccated and the cambium died part way around the trunk as a result. Sun exposure may have contributed. This often happens in the winter in locations that have cold, dry, sunny winters. The cambium began growing the areas it was killed. As this growth proceeds the bark over the dead areas loses adhesion. This is pretty much how all tree wounds are 'healed'. Your first pic shows the 'lip' of new growth after the bark has fallen away. Your third pic seems to show an instance in which the wound has been completely (re-)grown over ('healed').

Most of us must spend our first few years creating this kind of damage --> you've got that much of a head start. Congratulations!!

 

[Skye325]

Thanks, Osoyoung! Now I need to figure out how much of the branches I should cut. I feel like this could be a really good Bonsai and don't want to mess it up. Should I scrape off the rest of the bark that is peeling?

 

[0soyoung]

I suggest just removing what flakes off easily with your fingers. If you get to aggressive you will (re-)create similar damage that will make the 'healing' process take longer.

You have the opportunity to air layer most of those branches instead of just lopping them off and putting them into the compost/burn pile. It doesn't really cost you any time toward this becoming a bonsai, but would be a good exercise, and prospectively give you a number of clones to work with. Regardless, keep in mind that you probably want to produce a bonsai that is less than 3 feet tall. Hence you should only keep something like the bottom 8 to 12 inches of what you presently have. Also don't forget that Japanese maples will only sprout leaves and branches from nodes = those 'joints' you see every now and then along the length of stems. If you are anything like I was, you'll not cut low enough and then later realize the error. Not to worry as it just costs time getting to your objective. Being too aggressive, on the other hand, can be disastrous.

It is difficult to find the 'Goldielocks zone' (where everything is 'just right')- hence, my rationale for suggesting that you make a bunch of air layers.

 

[Skye325]

That's what I will do.
Last question. How much of the roots can I cut. I want to putting it into a smaller pot to start training the roots.
Thanks for your help.

 

[dbonsaiw]

How much of the roots can I cut.

Assuming the tree is healthy enough, you can cut pretty aggressively. Taking off up to 75% seems to be the going advice, but I've seen folks take off even more, especially with tridents.

 

[Shibui]

I agree with most of what @0soyoung has said except maybe layering the branches. Not worth the time IMHO. The dead patch may close over provided the tree is allowed to grow strongly for another year or 2. If you slow top growth you also slow thickening and therefore healing of scars.
JM can easily have 75% of roots removed. I routinely take more but best to stay safe for a start.
Not sure I would be ready to move a tree like this into a training pot but that will depend on your goal. Training pot will slow growth so only do this when the tree is close to how you want it.

 

[Potawatomi13]

Assuming the tree is healthy enough, you can cut pretty aggressively. Taking off up to 75% seems to be the going advice, but I've seen folks take off even more, especially with tridents.

Honestly not such hot advice for beginner. See where actual roots come out of tree under surface of soil. PERHAPS remove bottom 1/2 of roots at bottom of soil ball. When doing first development of tree best advice is give roots plenty of room. Shallower is likely OK, wider as well. Constricting roots during development phase not wisest course.

 

[Skye325]

Yesterday it was 65° so I was working on it. Last night it went back down to 32°. I think I did take off at least 75%. I am not happy about the pot, 18", it is in but I THOUGHT it was the only one that I had, until I remembered I had a training pot that is 25.5 x 20.5 x 9 that I think will be much better. This will give it more room to grow. Any suggestions on what type of soil to use? I need to change the soil also. Not a great day for me.

There are pictures below. Wanted to do something with the roots on the top but was afraid to touch them. It doesn’t look so pretty

Osoyoung, It was helpful to have your advice yesterday while I was working on it, Thanks!

Shibui and Potawatomi13, I am hoping the training pot that I have will give it more room to grow. I don’t think the pot it is in now will work.

I have air layered other JM 3 times and an apple tree once. I might cut off the top parts and air layer 2 branches lower down. That way it needs less energy for all the little branches. Does this make sense?

Let me know if you have any other suggestions.

I appreciate all the advice, thanks!

 

[dbonsaiw]

When doing first development of tree best advice is give roots plenty of room. Shallower is likely OK, wider as well. Constricting roots during development phase not wisest course

This was my thinking as well, but I seem to have been corrected. I started a thread a few days back on the topic of ideal box size and the conclusion seems to be to fit the box to the root ball we are dealing with. Bigger isn't always better when we are dealing with pots (as opposed to ground growing). I've built boxes that have been called out for being too big for the tree in question as well as others that were too shallow for a training pot even though they are quite wide. Once we put a tree in a pot, issues of aeration, moisture etc. become more pronounced. At the risk of confusing the issue further, I have also been advised that using a pot far larger than the existing root ball may contribute to the formation of the wrong type of roots - that is, unless the tree already has a substantial mass of feeder roots, the tree may very well send out thicker roots to colonize the soil, only forming the feeder roots when the walls are reached. I have no first hand experience with this, but it makes sense that the tree would act opportunistically and grow giant roots.

For example, I have a 6 foot shishigashira that has a 7 inch base and 5 trunks in a 20 gallon nursery pot that I was planning on repotting into a 20X20X3.5" pot. Putting aside the sheer cost of the 6 gallons of soil that would be needed to fill it, I was warned that this box was simply too big for this absolutely massive tree.

Honestly not such hot advice for beginner.

For what it's worth, I too am a beginner and this has been the advice given to me repeatedly. Personally, I've never actually measured the root mass that I start with compared to what I cut off and, therefore, couldn't tell you an exact percentage. When I am ready to repot a nursery tree, I take it out of the pot, bare root it with a small rake and chopstick, cut off the entirety of the tap root and all downward growing roots, cut off oddly shaped radial roots and trim the radial roots down. The whole mass gets a sprinkle of rooting hormone and into bonsai soil it goes with a really heavy watering. I may even seal the cut of the tap root etc. if I'm in a mood. The nursery maples I've dealt with had no problem going from a basically root bound 5-10 gallon pot to a 14X14X3.5" box with room to spare for the roots to run. Going forward, I may increase the depth of the boxes I make to 5" so I can fill it a little more and also have room in the box for a layer of sphagnum moss in the summer months.

To be sure, I am an absolute newbie and still trying to iron these issues out in my head. I am expecting a few starter trees planted in 3 inch pots each of which I was going to repot into 18X12X3" Anderson flats. I am now re-thinking these plans under the notion that they are simply too big for the trees in question.

 

[Skye325]

...thanks...now I'm not really sure what to do with this tree.

 

[Potawatomi13]

Not much help from conflicting opinions.

 

[Dav4]

...thanks...now I'm not really sure what to do with this tree.

If this were MY tree... ... I'd want to address the canopy and roots in one go. The nebari and trunk are the two most important factors to consider and develop for future success and setting this one on an appropriate path to becoming a good bonsai would mean cutting back the branches very hard while bare rooting it to see what the roots really offer. Unfortunately, I see at least two circling surface roots and that usually means there will be several more, large circling roots under the soil- with that in mind, a 75% root reduction would probably be a conservative estimate for that first root pruning. Mind you, I'm not telling you what to do but merely telling you what I would do. This should be viewed as a long term project, but much can be learned working with a tree like this over many years. Before doing anything else to the tree, you should spend a few hoursdoing some reading here and elsewhere. This particular thread is a great source of what can be done with maples and how to do it- https://www.bonsainut.com/threads/ebihara-maples.18215/. Good luck!

 

[AlainK]

I agree with most of what @0soyoung has said except maybe layering the branches. Not worth the time IMHO. The dead patch may close over provided the tree is allowed to grow strongly for another year or 2.

I agree with both of you : I first read Osoyoung's post, and that's what I would have said. But you may be right Shibui :

If you slow top growth you also slow thickening and therefore healing of scars.

I would probably choose "le juste milieu" : If you repot now in a good soil, and the weather helps, you could prune it now and leave two or three "interesting" branches to airlayer in June or even July. But I don't know what we we call here "the after-season" is like in Pa. Here, my maples lose their leaves in late October, or even in November, long enough to form roots...

 

[Skye325]

Unfortunately, I see at least two circling surface roots and that usually means there will be several more, large circling roots under the soil-

Yes, there are more under the soil but not sure I should cut anymore right now. Do you think I should do anything to the 2 circling surface roots?? I have been doing some research. Thanks for sending the link. And I like to hear what other people would do, so thanks.

If you repot now in a good soil, and the weather helps, you could prune it now and leave two or three "interesting" branches to airlayer in June or even July. But I don't know what we we call here "the after-season" is like in Pa.

I really like Osoyoung's suggestions of air layering the branches but also know that it will talk a lot of energy to keep all of them. I am going to pick one or 2 branches. I have air layered before and believe I would have enough roots by end of June. I want to cut off as much of the top as possible. I wonder if the air layer will work if I cut off the tops?

I have a picture below of where I want to make my cuts and the 2 circles are where I might air layer.

Regardless, keep in mind that you probably want to produce a bonsai that is less than 3 feet tall. Hence you should only keep something like the bottom 8 to 12 inches of what you presently have.

.....Being too aggressive, on the other hand, can be disastrous.

The arrow is 1' from the dirt so I am not sure I can make my cuts much lower than I have them. (if anyone wants to mark up the picture, feel free.)

As far as bonsai dirt, I can't use my own mix because it would make the pot to heavy and be too expensive. The above large training pot is the only one I have. It has been really hard to get pots. I was thinking of using a mix with:
Perlite 1/3
pine bark 1/3
Turface 1/3

I also have Haydite and granite grit but don't want to make the pot too heavy. I have never used perlite but I have read that people use it because it is light. If anyone has any suggestions on the above mix please let me know.

This is the second time I will be replanting into a pot. The first time was 4 days ago. Am I correct in thinking that this would be okay since it is still dormant?

Everyone, thanks again for the feedback!!

 

[0soyoung]

Your pic with an arrow seems to be missing. To keep things simple for the moment, my advice for spring pruning = don't cut below a visible bud

FWIW, I grow most everything in nothing but Turface and dress the surface with chopped sphagnum if it dries too quickly. The exceptions are potted 'patio trees' in medium-sized landscape bark with bit of garden soil tossed in (2:1 -ish by volume). I occasionally do this with trees with freshly dug trees. I don't think mixes with components that float and others that don't are a good idea as the mix will tend to lose homogeneity if one is not extremely careful watering.

The important point to keep in mind is that while roots must be kept damp, the must get oxygen.

I really like Osoyoung's suggestions of air layering the branches but also know that it will talk a lot of energy to keep all of them

IMHO, life is easier if one ditches this metaphysical energy BS. Foliage demands water from the roots. Foliage produces carbohydrates. Carbohydrates, produced by photosynthesis, is the ONLY energy in trees. Layering does not demand anything other than water with some nutrient minerals from the roots. A layered branch does not feed the rest of the tree any longer, just like it had been cut off.

Water and minerals go up the tree in the xylem (wood). Carbohydrate comes down the tree in the phloem (inner bark).

 

[Skye325]

Your pic with an arrow seems to be missing. To keep things simple for the moment, my advice for spring pruning = don't cut below a visible bud

There are a lot of buds on this tree. Not sure what you mean. I understand what you said about the branches I am going to air layer and will leave more of those branches intact.
Picture should be below.
Thanks,

 

[0soyoung]

you should only keep something like the bottom 8 to 12 inches of what you presently have.

I now understand the scale of things. So your bonsai, IMHO, is something like this with a canopy you build on top. Your cut/layer plans fit well with this understanding. Of course you may have branches form (or that you produce by thread grafting) in places that open new possibilities. You might even wind up layering 6 to 8 inches above the present soil line (although I'm not recommending that you do so now).

Some design issues to think about are that you want the canopy to lean toward the front. Its crazy, but I find trees with canopies moving back impress me as recoiling from me (I.e., very unfriendly). Also, scars generally go with masculine forms that are short and fat. Feminine forms tend to be the opposite. This tree is in the ambiguous land in between.

Anyway, it should be lots of fun!!
Enjoy.