@Leo in N E Illinois has a very good point on timing for you as first time in a situation like this to an important tree. Azaleas were and are regularly repotted after bloom… until the climate changed and summers got hot in various areas around the world. Now de rigeour is springtime.
Yet as
@BillV has stated repeatedly, one can pretty much do any kind of work all year
given proper after care…
So keep things going is an option, go for it. I highly recommend considering the drill technique use to help water penetrate into the core in the interim. We ended up drilling this tree last year and later repotted it in July
A comment on rootwashing wedges. To do this one has to remove half of the existing soil. Based upon my experience one might as well just finish the job. Once half of the soil has been removed the last half is comparatively easy.
Cutting off half of the core as wedges is likely not a good strategy in this situation half of the roots that were having trouble taking up water would be gone, reducing the tree to try to survive with half of its absorptive surfaces.
45 days ago we rootwashed a number of azaleas with media half Kanuma, half native soil. The native soil core was totally impervious to water and very hard.. in fact I used my water wand on full power with a heavy chopstick to get up to the core soil and the it was bone dry. Sounds like your situation. I’ve done a few landscape azaleas and sometimes it’s like this.
Soaking wouldn’t help at all. It was water blast and chopstick, turn the rootball around a bit every couple minutes and attack from different sides. It took me three times as long to completely rootwash compared to any other tree we have. There are a couple images below.
Note this was a former landscape azalea, so crossing roots in the nebari and non functional roots in the core we’re cut back along the way.
At the core. Native soil still needed to come out of all the nooks and crannies in between the root areas. Attack from top and bottom.
Last 10% to do.
Today
btw: One of our members,
@Shibui is an expert in large azalea work. I believe he does it pretty much all year. I’m positive he could add some helpful ideas from his experience.
cheers
DSD sends