We planted a 7 gallon spruce tree this May and it has been dying branch by branch for the last month. We continue to water it every 6 days for 20-30 minutes with a slow flow hose, sometimes twice a week. It gets mostly sun, and we have had basically no rain this spring and record breaking temps this summer in Montana.  No one has added herbicides, and there doesn't seem to be insect infestation (although insects are killing our much older douglas fir nearby with a top-down death as well.)

I keep trying to water more to save it, but don't want to over water as well...every week, another branch is dead. Is it a lost cause? As of now, temps are in the 80's day/50's night, but do go into the 90's at times.