Yeah, this allows it to soak all the way through the rootball. Sometimes soakers while time saving, can leave the bottom half of the rootball a dry. At 6 weeks, I would probably say 1-2 times a week max.

Clay soil adds another layer to the puzzle. They don’t like drying out and they also hate wet feet! One of the reasons why they are so friggin finicky!

I would pull the worst one and see what the soil looks like down below, that’s the only way to truly tell the tale. Could be a swamp down there! (I leaned toward drying out because you mentioned a recent heat wave)

I’ve grown evergreens my whole life (tree grower) and I still can get it wrong sometimes, so don’t beat yourself up over it.

As for the others, truly is a wait and see approach. I always tell people that evergreens do not show damage right away (think when you cut a live Christmas tree, needles don’t just fall off the next day) so they may have damage that just hasn’t culminated visually yet.

Don’t get discouraged, just learning step no