How to repot a 5 Gall Juniper? And style ideas

I need some advice on how to repot a juniper that was bought in a 5 gallon plastic nursery pot. There are a bunch of roots, some of which are fairly large growing in every direction. The tree has had some styling but is far from done. I have repotted smaller bonsai with no problem but I have never worked on something this large and dont want to take off too much root too quickly. Someone told me I should only cut about a 1/4 to a 1/3 off and repot it and let it heal for a month then cut another 1/4 or so off repot and let it sit...so on & so forth. Thoughts???? Any advice or ideas on what I should use as training pots (hopefully something cheap and easy since it will not be in there very long) untill the roots are small enough to fit into a more perminate home?

Thanks!

No, leave it until the fall or if you have the patience leave till spring. Dont cut any roots right now. If its completely pot bound, then you can loosen the root ball a bit and slip pot it but do not cut roots right now.

for a new container I would consider building a woodend box out of 5/4 x 6 pressure treated decking or similar. Either butt the bottom boards and drill drainage holes, or leave a small gap between the boards and staple on some regular plastic mesh as you would use in a ceramic pot.

Now is not the time to be thinking about repotting a juniper here in So. Cal.. You can probably do it in October or early spring. I usually go from a 5 gallon can to a cut off 5 gallon can- we cut them down to about 1/3 of their original size. For the first repotting I'd suggest waiting until late Feb./ early March, but in the meanwhile you can start to work on the top.

I would do it in the Spring.

Junipers, especially Shimpaku and Itoigawa Shimpaku resent having their roots cut.

Reduce the roots every year by 1/3, so long as it is healthy and gradually replace the soil with fast draining Bonsai soil.

I use Boon's mix: 1/3 pumice or perlite, 1/3 small lava rock and 1/3 Akadama.

There are other soil mixes you can use with Turface mixed in etc.

It must be well drained.

Thanks for the advice, I will wait untill spring to repot. In the meantime I have done some shaping of the top. I am waiting for that portion in the upper canopy to fillin more and I and thinking of trying to bring some of the lower branches a bit higher and tighter/closer to the top. Any advice or direction on shape? I'm open to ideas.