I've done that,but usually planted in the Fall or Spring.Where's your location in the US? Brady

I'm in portland, or. I went and purchased 2 trees yesterday in pots. I made the mistake of thinking there would be a pretty solid root ball in the pots. On the way home from the nursery, nearly all the soil came out of the pots. I repotted them in 18" pots, but essentially they were bare root at that point. Im worried they are going to be really shocked and stunted from being transplanted this time of year. Is there anything I can do to help them out? Should I prune them back hard, or just let them be? Anything else I should do? They are roughly 1" diameter at the base and maybe 3' tall.

Are they whips or do they have branches and they were growing in pots at the nursery?Being that tall,I'd probably not prune the top at all.
I put mine in a potting mix made up of about 60% conifer bark mulch(Pine and or Fir)20% Peat moss and 20% Perlite.That makes a breathable,well draining medium. Brady