Just keep an eye on it.......it is very likely just fine. JM's can take a bit more abuse than most imagine and I routinely repot newly purchased trees at all times of the year, however I have never felt compelled to wash all the roots before repotting, despite what theorists say are the benefits :-))

I never wash off all the roots either. I don't think the risk is worth it. That's a big change in the root environment. I've planted hundreds of Japanese maples over the years and never felt it necessary.

Keeping it wet the entire time was a good move. It doesn't take long for those small root hairs to dry out. Your maple should come out OK after it gets over the initial wilting and you keep it in shade for awhile until the roots adjust.

Definitely keep it in shade and do not fertilize for a while.

Like GardenGal48, said it should be fine as long as the roots didn't get exposed to hot sun or get dried out. It sounds like you were on top of that.

I'd be lying if I said I've never done that. As a matter of fact, I did it 2 weeks ago and didn't think twice about it. I got a 'Mayno No Sato' online a few weeks ago and did the exact same thing you did. It's doing quite well, showed no sign of stress, and is loving its new shiny blue pot and GM!

Thanks. The roots did not dry out. So far it's looking good (5 days in). I just looked up the tree Manyo No Sato and that's very nice. I hadn't see that before. I love the colors of the leaves.