Satsuki starts -- potting up advice?

Hey! I'm kinda new to all of this, but I just got an order of Satsuki starts in (From Azalea Hill Nurseries in Arkansas, fwiw) that are much larger than I expected -- when they said "newly rooted cuttings" for $3.25, I was expecting some twigs in 2" plugs, not these guys and their fat 4" root/peat chunks!



I am curious as to how I should go about potting them up right now. Given the wee bitty fine roots on azaleas, would it be wise to try to hose out as much of the peat mix as possible and pot them into a kanuma/pumice mix at this point? (I'm going to try and train about half of them into exposed-root styles, so getting them into something with a large particle size as soon as possible would be ideal.)

Or should I pot them into a more conventional media until next spring?

(For what it's worth, I'll be overwintering them in a garage that never gets below ~40F.)

I would pot them into slightly larger pots using something similar to what they are in. Loosen the outer roots a tiny bit, but not too much. You want all of the the soil in the pot to wet and dry at the same rate. You can do a more complete report in the spring.

Nice to see Ronnie did a good job on those.

Since you are in zone 6, these may get damaged in your winters. So I would also overwinter them indoors as you suggest.
I have heard that if temperatures are low enough, they can take total darkness and be fine. But if it gets too warm, they metabolize and they will starve in darkness.
My own experience is that large potted azaleas sometimes do not wake up in spring. They never leave dormancy and very slowly start to wilt. So no new growth in April, no blooms, and then only in late May, they truly start to wilt. I suspect this may because of too little water. It is easy not to water plants indoors. And humidity will be lower indoors as well. Lack of ventilation is also a risk. Ideally, you have moving air in your garage. But I cannot explicitly state that stale air indoors will cause fungus to grow. That may be the risk factor, though.

I would also see if there is a need to wire up the main trunk and get some movement into it. Or if you want to do this next year. Then you have to decide how you want to style it. Single trunk or multi-trunked. They are very basically dominant, so what they like to do is grow shoots from the base, and direct a lot of growth vigor into those so that quite quickly they are equal in size to your main trunk(/branch).

This is kind of ok for a young plant. You also want to fatten them up. And a low branch is nice for a sacrificial branch. But if you have several, you can get reverse taper.
Also, people sometimes make the case that by removing every sideshoot, you direct growth towards the apex. And the shoots growing from the apex elongate more. And then when you limit that to one shoot as well, you have a very easy time growing it tall quickly. Then you can wire. And then grow side branches to fatten the trunk. I do not know yet from experience if indeed pruning away sideshoots speeds up the vertical growth rate. I often think that more branches means more leaves means more photosynthesis, means more sugars, means more of everything faster. I will have to test this out at some point by comparing two batches of cuttings.
If this variety is very vigerious and buds from old wood spontaneously and reliably, completely removing and regrowing sidebranches for a single trunk design is the way to go. Only when you are somewhat satisfied with the girth of the trunk, start growing the actual branches.
If it is less vigorous, try to keep branches as if it was a pine. A bit more risky as it might cause a bit of reverse taper.

I see you have very fine kanuma. I would only use that grain size for cuttings. I think growing cuttings in peat/bark/perlite is very good. So you can use a similar mix and mix in kanuma. For my climate, I have not found yet that kanuma is superior for growing cuttings/seedlings. I think I might like it for indoor growing, because it allows you to water a lot. Which can be an advantage indoors. Watering a lot when a plant is in peat long term may cause problems. Especially indoors with lack of ventilation.

Good luck.