I put my serviceberry in the ground with some soil remediation and it still looks very sad.
Hi Rita,
I am surprised that your serviceberry is struggling, they are pretty tough. You have that radiative cooling thing where you are I think; maybe try and set up a bit of micro-climate, wind shields etc. add some more organic matter because your soil is very sandy and will leach a lot of nutrients. I guess you'll have good chances with the blueberries. Do you have access to manure ?
It just occurs to me that regarding your serviceberry it might be a
VAM thing (Vesicular Arbuscular Mycorrhiza). Go and find a healthy and thriving serviceberry a get some soil from nearby the roots (you could take a cutting while you are at it...). You can also get VAM online then the fun part is trying to get it to interact with your serviceberry.
Good luck with your project.