Fall.

Would the azaleas survive in a pot for another month, though?

Actually the rhododendron that is out of alignment with the bed shape - including spilling over the lawn - is the one to the left. Whereas the one you have circled still has some space left in front of it. And is relating to the two trees behind it, whereas the other is just sort of floating and on its own. So how about moving that left one instead?

Also have you moved a 12' wide shrub before? One that is a kind that will have to come away with an intact soil ball, rather than being bare-rooted? Because wrestling with a specimen of this size and weight is not going to be like moving a chess piece.

Finally if the azaleas were planted somewhere else besides right in front of the rhododendrons that would of course eliminate the pressure to get the rhododendrons moved earlier in the year than is desirable. Which at this point is being created pretty much entirely by the fact that the azaleas are already on site and waiting to be planted.

I'm afraid it's not that simple, @Embothrium :-/ My dog passed away about 10 years ago, and I made her a nice grave then bought these rhodos that were SUPPOSED to be 4-6' wide. I put them on either side of her grave, and now the one on the right completely overwhelms her grave.

I don't know if you can tell from the pics, but there's really no grass in front of the rock border. It looks green in the pics, but that's really just weed. So every year it's been a battle to try to get grass to grow, and every year I fail.

This week I've been working to move that rock border about 20' forward, then digging up the weeds manually, then mulching the whole area and converting it to a shade garden. That's why I'm hoping to move this rhodo to the other side, and I have a layer that I started 2 years ago that I hope to transplant to the middle. Then I have other shade plants to go in front of them.

As for whether I've ever done this... nope! I've dug up and transplanted a handful of small trees, two layered rhodo transplants, and a much smaller box bush, but that's all. I've read that rhodos are pretty tough, so I was hoping it would forgive me if I screwed up too badly?

Based on the articles I've read I figured that I would start digging about 3' from the middle (the back is pretty bare so it's easy to get to the middle from there) and dig in a circle around it about 1' down. Then I hope to be able to dig sideways to get under it from the back, and when I can tilt the whole thing then I can slide a tarp under it, then finish up the digging from the front.

From there my plan was to dig a new hole that's slightly bigger than what I dug up, water it with a running hose for about an hour, then slide the tarp and set it in place. Fill in, water some more, and done.

Thoughts?

My alternative would be to buy 3 more, but I hate the thought of it taking 10 more years for my new garden to look good :-( Especially since today (Monday) is my birthday, right now 10 years sounds pretty daunting!

Root ball will have to be small enough to move without excessive strain. Tie the branches together first to allow access.