AusBonsai

I found a Japanese maple in a nursery in need of an overhaul. Leaves were bit burnt and ragged probably because the tree is really badly pot bound i.e I couldnt brush the soil to check the nebari as feeder roots everywhere.

It got my attention because trunk had nice movement and branch structure has potential to wire.. even though the leaves looked sad.

Wondering if I should either:

1: slip pot it to bigger pot for autumn/winter and wait until spring to do full root branch prune?
2: full root prune - repot and just wire now and hope for the best over autumn/winter?

Greetings.
Now is probably a good time to prune some branches back but as for the roots, just wait a couple of months. If the tree isn't healthy, try not to prune too many roots off, try to comb them out the best you can and repot it into something bigger and let it recover.

Just drive a chopstick into the rootball a number of times and make sure it drains ok when you water.

Water and fert now, and give it a bareroot and overhaul in late winter/spring.

Where in NSW you are located? The Southern Tablelands has now received the first significant frost for the year. Now is not a good time to prune and repot as you may stimulate new growth that will be burnt back by frosts and set the plant back even further. I agree with Scott, make sure the pot drains and be patient and wait for the end of Winter to root and branch prune.

Should the header be too late or too early?

I would wait for a month or so. In my experience, any time in winter should be ok but if you root prune early be careful not to keep it too wet or the cut roots can rot. Certainly safer to wait until late winter. As Scott points out, the biggest risk in keeping pot bound stock is that it is hard to get water to penetrate the tight rootball. Poking holes is 1 possibility, regular soaking to get the rootball properly wet is another way to look after it. Simply slip potting does not solve the problem.

We should note that commercial wholesalers are already lifting their stock to get early bare rooted trees into the retail nurseries. Survival rates will be close to 100% so why are we so pedantic about waiting until spring?

i second that shibui, weve just received a load of
bareroot crepe myrtles and ornamental pears.
fruit tree of course will be later. we had a few days
of 30 degrees hee in mildura 2days prior receiving
our bareroot trees last year they sat flat in the paddock, then
the following 2 days frost no protection. we had all up
16 casualties out roughly 450 trees mostly figs and d agen
prunes. so im in the opinion we can chill a little