Hot, hot, hot! Many trees are florishing in this heat. Mainly tropicals. Junipers are having a little trouble , but spruces and larches are in trouble. They shuld at least be sitting on the ground or have their pots buried in the groung. put a reflective material (foamy white shelf liner) over the soil. on the bench the pots and soil can get over 125 degrees and cook the roots.
A cooling mist in the middle of the day can help a lot. Reduce the amount of fertilizer that you use. The trees cannot use it anyway.
Different soils can require changes to the way that you water. sometimes lesser amounts more frequently work better then drenching the trees once a day.Misting might help keep the leaves moist whe they are drying out faster than the roots can provide.