sorry if this has been asked a hundred times before, i don't have time to search archives. I planted a dozen 5 foot tall arborvitaes 5 weeks ago. They are browning really bad from the inside out. I stuck my hand down into the dirt and apparently the dirt settled around the root ball and i have huge air pockets around the balls. i did my best to fill them in. What can i do to save these trees? Are they too far gone? is it worth digging them up and fixing the planting? i don't want to do all that work if the damage is unfixable. How can i jumpstart their rescue?

please help?