Mugo repot and please criticise

[Manbris]

Hi! Started to HBR the mugo mop. But discovered very thick circular tap root buried. Could this be a graft tree? I put it in a grow bag and gonna do the other half this fall or next spring? And then start to think about styling. Any ideas would be great. Thanks!

I use lava rocks, fine pine bark, and perlite mix plus some soil from original tree and in a 7 gallon growth bag. Would this be good? And be considered as bonsai mix? I have a few more in nursery cans and planning to do the same to a growth bags.

 

[Shibui]

I cannot see any indication of a graft site on that trunk. Doesn't mean it is definitely not grafted but certainly no need to worry about a graft.
Circling roots can come from seedlings or cuttings and have nothing to do with a grafted plant. More about how the tree was originally grown.

Which half of the root ball did you bare root? Looks more like you've just scraped a little old soil away from the surface, unless you did more after those photos?
IMHO you really need to go way deeper until you get to where the main roots join the trunk. To do that you usually need to cut some of the smaller roots that grow up and around the trunk close to the surface. Until you can find out where that thicker roots starts and where it goes to it's really hard to advise if it could be moved or removed.

I use lava rocks, fine pine bark, and perlite mix plus some soil from original tree and in a 7 gallon growth bag. Would this be good? And be considered as bonsai mix?

Does it matter if you are using a 'bonsai mix' while the tree is in grow bags?
Don't be fooled into thinking there's only 1 'real bonsai mix' Many successful growers use a range of different soil mixes. Success is more about managing your care regime to suit the soil than having a special soil. It's hard to even guess whether your soil mix is appropriate without knowing the relative sizes of each material and what proportions you've used in the mix.

 

[AshleyMammal]

If you haven’t already, checkout the mugo bible:

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Compiled Vance Wood on Mugo Pines

Jun 5, 2015

Posts compiled from Bonsai Nut by Vance Wood from 2010 onward on mugo pine care and development

• Lazylightningny
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Years of research by Vance Wood who is sadly no longer with us.

 

[Manbris]

I cannot see any indication of a graft site on that trunk. Doesn't mean it is definitely not grafted but certainly no need to worry about a graft.
Circling roots can come from seedlings or cuttings and have nothing to do with a grafted plant. More about how the tree was originally grown.

Which half of the root ball did you bare root? Looks more like you've just scraped a little old soil away from the surface, unless you did more after those photos?
IMHO you really need to go way deeper until you get to where the main roots join the trunk. To do that you usually need to cut some of the smaller roots that grow up and around the trunk close to the surface. Until you can find out where that thicker roots starts and where it goes to it's really hard to advise if it could be moved or removed.

Does it matter if you are using a 'bonsai mix' while the tree is in grow bags?
Don't be fooled into thinking there's only 1 'real bonsai mix' Many successful growers use a range of different soil mixes. Success is more about managing your care regime to suit the soil than having a special soil. It's hard to even guess whether your soil mix is appropriate without knowing the relative sizes of each material and what proportions you've used in the mix.

Thanks very much master Shibui. Yes indeed a scraped a bit more after pics. It was raining hard yesterday, I did it in a couple of gos. Any reason to not do it in the rain? I did the side close to the biggest tap roots as I did not see much growth on this side so thought it was weak. I try to be a bit more careful with them, happy to take a bit longer. I killed a 20 year old red pine last year still not over it yet. Can I go again this fall to digger harder on the other side?

It is still a bit wet today so may not be the best pic - here is after repotting. Consider how thick the circular tap roots appeared to be - can it be kept as a feature going forward? I was trying to go close to the trunk but this circular tap root just so thick and go around and then into the soil - had to do a lot more than half root ball to get it clean. But I think i have a better pic with this tree now- did not know tap root before.

I will get another pic when weather dries up- it is almost a third thick of the main trunk and twice thick than largest branches.

 

[Shibui]

It was raining hard yesterday, I did it in a couple of gos. Any reason to not do it in the rain?

Ireland is world famous for it's rain. No problem for the tree being root pruned in the rain. much more of a problem for the person doing the root pruning.

I did the side close to the biggest tap roots as I did not see much growth on this side so thought it was weak. I try to be a bit more careful with them, happy to take a bit longer. I killed a 20 year old red pine last year still not over it yet. Can I go again this fall to digger harder on the other side?

I can understand your reluctance to root prune after a failure. the question is whether the previous problem was down to the root pruning or something coincidental that you have not considered.
HBR stands for Half Bare Root and includes the entire root ball, not just the surface. Looking at the pictures I'd estimate you did maybe 1/0 bare root? looks like the entire lower part of the original root ball is untouched in the photos but maybe that's what you did after the photos? at that rate it might take 5-10 year for you to deal with that thick root and most of the other problem roots here.
Not only can you half bare root pines (remove half the potting soil) you can also safely remove up to half the existing roots without affecting the tree and I'd consider that quite conservative.

I have not yet tried Fall root reduction on pines as I'm accustomed to doing Spring root pruning and seem to be able to get all my trees done in winter/spring. I know some very good growers do fall root prune so I take their word for it's safety and effectiveness. I just cannot say how much is safe or not safe as I have no personal experience.

It is still a bit wet today so may not be the best pic - here is after repotting. Consider how thick the circular tap roots appeared to be - can it be kept as a feature going forward? I was trying to go close to the trunk but this circular tap root just so thick and go around and then into the soil - had to do a lot more than half root ball to get it clean. But I think i have a better pic with this tree now- did not know tap root before.

It may be possible to use the thick root in the design but I would not make that call until I can see more of the real roots, not just a few little floaters on the surface.
Not sure whether that circling root would be considered a 'tap root'. Trees rarely have a 'tap root'. The initial seed root goes down but soon splits into many lateral roots and the initial down roots disappear. My guess is that's just one of the early lateral roots that was curled around in a smaller pot when this tree was much younger and for some reason it has grown a bit better than the others though we can't yet see any other lateral roots growing from the trunk. It is not unusual to come across a whole nest of these curled roots as you remove the surface soil but hope that's not the case this time.

 

[Manbris]

Ireland is world famous for it's rain. No problem for the tree being root pruned in the rain. much more of a problem for the person doing the root pruning.


I can understand your reluctance to root prune after a failure. the question is whether the previous problem was down to the root pruning or something coincidental that you have not considered.
HBR stands for Half Bare Root and includes the entire root ball, not just the surface. Looking at the pictures I'd estimate you did maybe 1/0 bare root? looks like the entire lower part of the original root ball is untouched in the photos but maybe that's what you did after the photos? at that rate it might take 5-10 year for you to deal with that thick root and most of the other problem roots here.
Not only can you half bare root pines (remove half the potting soil) you can also safely remove up to half the existing roots without affecting the tree and I'd consider that quite conservative.

I have not yet tried Fall root reduction on pines as I'm accustomed to doing Spring root pruning and seem to be able to get all my trees done in winter/spring. I know some very good growers do fall root prune so I take their word for it's safety and effectiveness. I just cannot say how much is safe or not safe as I have no personal experience.

It may be possible to use the thick root in the design but I would not make that call until I can see more of the real roots, not just a few little floaters on the surface.
Not sure whether that circling root would be considered a 'tap root'. Trees rarely have a 'tap root'. The initial seed root goes down but soon splits into many lateral roots and the initial down roots disappear. My guess is that's just one of the early lateral roots that was curled around in a smaller pot when this tree was much younger and for some reason it has grown a bit better than the others though we can't yet see any other lateral roots growing from the trunk. It is not unusual to come across a whole nest of these curled roots as you remove the surface soil but hope that's not the case this time.

Thanks Shibui. Ok I will try to go further next time. Still got 5 trees to do. May just leave this tree alone till along till next year.

- sorry I did remove bottom part more than the picture but certainly as you say can go harder more. Will keep it in mind.

 

[Shibui]

Thanks Shibui. Ok I will try to go further next time. Still got 5 trees to do. May just leave this tree alone till along till next year.

Good call. Always good to hasten slowly to build up confidence, especially after a previous disaster.

 

[Manbris]

Good call. Always good to hasten slowly to build up confidence, especially after a previous disaster.

Thanks Shibui - here is another one i did today
Thread 'dwarf scots pine 1 repot - progression post -please criticise'
https://www.bonsainut.com/threads/dwarf-scots-pine-1-repot-progression-post-please-criticise.68264/