Purchased trees, wait till fall to plant, or get in ground ASAP?

Purchased trees, wait till fall to plant, or get in ground ASAP?

Hi, friends. I perused the topics, but didn't see an answer to this specific question. The local nursery recently had a huge 50% off sale and I bought a flowering plum tree, a red-twig dogwood shrub, and several firethorns at a great deal. I know this isn't an ideal time of year to plant, so I was wondering if it's better to keep them in their pots, in a cooler area of the yard, and well watered and wait till the fall, or if it's better to get them into the ground as soon as possible, maybe planting them in the evening on a cooler day? (I'm in Boise Idaho, zone 6a and our weather has been in the 80's-90's and looks to be staying that way in the near future). Thanks, everyone!
Just a few snaps of what’s blooming in my yard right now….

Just a few snaps of what’s blooming in my yard right now….

frost

frost

Fox Red Curly Sedge

Fox Red Curly Sedge

What sort of bush is this?

What sort of bush is this?

How to make it look like an 18 year olds room

How to make it look like an 18 year olds room

Crocuses

Crocuses