Japanese maple structure reduction pruning

[vbakatare]

I have a bloodgood maple that I got from Costco before being interested in the craft of bonsai. Its a interesting piece for me because there is a piece of the graft that’s growing so it gives a different color contrast. I do recognize and understand that the grafted piece will be more vigor and aggressive than the upper portion and will need to keep it more in check.
My conundrum is that the roots are now growing into the ground. Do I do a repot? if so, when? Or do I do the structural reduction in the fall, knowing that the roots are fine, allow the tree to recover and then repot?
Thank you for your advice and please be kind

 

[Hack Yeah!]

I'd heavily consider just using the rootstock as the future tree and cutting the bloodgood off now. Then repot in spring.

 

[Srt8madness]

I think you'll have to make a choice which you keep, as you can see how strongly the root stock is growing, I think it will likely overtake the cultivar. That generic maple variety would actually make a better bonsai in my opinion.

You definitely don't want to repot during summer. People who know maples far better than I can advise on timing and strategy

 

[Srt8madness]

I think chopping to the lowest branch on one of the green branches (and you'll likely need to pick one or the other) could give you some good movement and taper.

 

[vbakatare]

I'd heavily consider just using the rootstock as the future tree and cutting the bloodgood off now. Then repot in spring.

The thought did cross my mind since how vigor and aggressive it's grown. When I bought the tree, the graft had a tiny growth coming out and I let it grow thinking "I'll let it grow and airlayer it later". I'm thinking of that option as well. Is now a good time to do that? or should I wait until the fall when the leaves drop?

 

[vbakatare]

I think chopping to the lowest branch on one of the green branches (and you'll likely need to pick one or the other) could give you some good movement and taper.

that's true and a good option. in your other post, are you suggesting on keeping the bloodgood and trashing the rootstock?

 

[Paradox]

that's true and a good option. in your other post, are you suggesting on keeping the bloodgood and trashing the rootstock?

No the suggestion is to cut the bloodgood and keep the rootstock but pick one on the green trunks to be the tree and cut the other. That double trunk as it is won't make a good tree so you should cut one.

Best time to repot is late winter/early spring as the buds just start to swell. You can do the repot and reduction at the same time.

I also agree you can do the reduction of it now and get rid of the Bloodgood and one green trunk. Leave everything else for now.

Either way dont repot until late winter/early spring.

 

[Shibui]

Agree that the different growth rates will be an ongoing problem. It will also look odd when you have a tree with 2 completely different colors and internode length.
Whether to keep one or the other is up to you but after trying bloodgood and similar cultivars as bonsai and not getting great results I know which way I'd choose.

As for the roots in the ground: It will depend how far the roots have grown and how thick they are coming out of the pot but I regularly just chop escaped roots below the pot. No need for a complete repot and the root chop can be done almost any time. You will probably need to water a bit more and keep it sheltered initially to compensate for the lost roots but generally there's no problem cutting escape roots as the tree should still have a good complement of roots in the pot.
JM don't seem to have any problem with root prune and top prune together or soon after so you can do the structural prune in autumn then repot in spring or do both in late winter or spring. I would NOT do a full repot while the tree has leaves.

 

[rockm]

I'd top it out and eliminate the bloodgood stock completely. Bloodgood isn't all that great for bonsai, long internode length being the primary problem with them. They don't compact as well as plain old JM. The rootstock that the bloodgood has been grafted onto is probably better for bonsai uses.

 

[vbakatare]

I'm getting a good overall answer from everyone. I think I'll wait a couple more months until the leaves start falling off and I'll do the work

 

[Lorax7]

I agree with others that you need to choose or otherwise separate the Bloodgood from the rootstock via a layer. I have seen decent bonsai made with Bloodgood, but it has to be a larger sized bonsai for it to look right because of the longer internodes. So, whether or not to do an air layer really boils down to the question: Do you want a big maple bonsai in your collection or even just to plant a Bloodgood as a landscape tree somewhere in your yard? If yes, then go ahead and do a layer next spring. But, if you only want shohin size trees, it’s not worth your time.

 

[Hack Yeah!]

I'm getting a good overall answer from everyone. I think I'll wait a couple more months until the leaves start falling off and I'll do the work

You've got a lot of growing season left. If you cut off the bloodgood now it can start healing over the cut site for the rest of the season. It'll also provide you with a glimpse of what's left to start thinking about what style and size you may want to develop. That'll become easier after you complete your first thorough repot.

 

[vbakatare]

I agree with others that you need to choose or otherwise separate the Bloodgood from the rootstock via a layer. I have seen decent bonsai made with Bloodgood, but it has to be a larger sized bonsai for it to look right because of the longer internodes. So, whether or not to do an air layer really boils down to the question: Do you want a big maple bonsai in your collection or even just to plant a Bloodgood as a landscape tree somewhere in your yard? If yes, then go ahead and do a layer next spring. But, if you only want shohin size trees, it’s not worth your time.

hmm...if I were to want to airlayer, should I wait until spring? or dobi have time to do it now?

 

[Jrmcmich]

hmm...if I were to want to airlayer, should I wait until spring? or dobi have time to do it now?

Wait till spring for air layer. Agree with others on removing bloodgood part. You might want to do it now while it’s obvious with leaf colors vs when leafs fall

 

[Lorax7]

hmm...if I were to want to airlayer, should I wait until spring? or dobi have time to do it now?

Wait until spring

 

[Paradox]

hmm...if I were to want to airlayer, should I wait until spring? or dobi have time to do it now?

Spring after the leaves have hardened off