Help for a pine noob

[bonsailevel:master]

I'm going to put this Mugo in a pot with plenty of room to grow before a repot in 3ish years. I will be using bonsai soil. I'm only going to tease the outside of the roots a bit, at a bare minimum. It basically will be a slip pot situation. My question is this,...
If I do this now when should I do the minimal trimming? It has a classic wagon wheel whorl in the middle that needs to be addressed. Then maybe one or two more for basic design setting. All my trees are deciduous so I don't know much about pines. Any suggestions or links to any information on a pine at this point in development would be appreciated.

 

[TrevorLarsen]

This is considered the best practices when it comes to Mugos. Follow it and you will succeed.

Tutorial - Compiled Vance Wood on Mugo Pines

Compiled Posts by Vance Wood on Mugo Pines UPDATED 5/20/2018 Vance, I have gathered posts you made on B-Nut over the years from the archives. I have consolidated this info below. I appreciate your sharing your years of experience with this...

www.bonsainut.com

 

[Wires_Guy_wires]

That compiled post is pretty good.
I stick to it too, except for the repotting practice because it did yield one result: certain death.
So I do spring repotting for mugo and that works well.

 

[pandacular]

Every professional that I have mentioned the idea of slip-potting a young, healthy tree to has responded with a confused look, and wonder why I would do such a thing. I think it's something of a fallacy to assume that not working the roots is good for the tree. If your goal is to transition it to bonsai soil and start developing fine roots, then a slip pot will do very little for that.

 

[CptnGlyn]

I think that with any tree, slip potting a tree in poor soil into a bigger pot and surrounding the poor soil with bonsai soil will result in the desired fine root growth, but on the periphery of the root ball. This might have its place, for example when taking on a new tree which has been heavily neglected, in order to help it through to the best repotting season, but for the most part any gains resulting from the extra rooting volume will be lost two fold when all those fine outer roots must be trimmed back at the next repot.

 

[pandacular]

Yes, usually I see it suggested that if your goal is to minimize distress, you should work the root ball in sections. Do one half one year, then the next at the next repot. I’m not very familiar with pines, but on such a young tree, I would not be overly cautious.

 

[TrevorLarsen]

I have only had a problem when I repotted in spring (the tree almost died) when I followed that guide and repotted in July I had zero problems.

 

[Paradox]

I have repotted Mugo in both spring and summer.
I have found summer repots to tend to sulk and recover much more slowly than a spring repot which tended to bounce back much faster.
I prefer to repot in spring and then protect from freezing if needs be.

 

[bonsailevel:master]

Thank you all for your replies with opinions/info. Found the tutorial from Vance Wood very interesting. I will definitely hang on to it for reference. He says in it that the best time for a repot on Mugos is late June to August, early July being the best time. Obviously researching on my own turned up opinions of late winter/early spring being best also, including Eisei-en. In that same breath though Eisei-en did not specify between an established tree vs nursery stock which Vance specifically notes his summer recommendations is for nursery stock. So for a $15 roll of the dice I decided to repot now. Pulled the soil down and spread roots out. Seeing the roots I had to work with I didn't really feel the need to rake them out too much. All I cut out was 2 thick long roots and 15/20% of existing soil. I'm assuming after care is the biggest factor in success. It will be well taken care of