In my experience Larix trees are very delicate about repotting. The one repotting with the most risk is the one right after the first one after you collect it. Once I even had a larch which was practicly finished and when it was repotted, it died. And I have not removed a single root... So the best time is to do it when they start to but.
Now it was finally time to repot this half cascade larch of mine. I placed it into a pre-ordered pot by Erik Križovensky.
The tree last summer, still in the previous pot in which it was growing for 4 years.
Aplying Keto-tsuchi to the rather steep soil level.
Resumed with moss.
The finished product.
And here is the tree when I found it in nature in 2007.