I have approximately 20 cypress along 2 walls. Partner, Latin, did not understand how miracle grow works, and poured one packet directly onto soil of approximately 10 trees, without water, this was about 4 months ago. The top halves of these trees have turned brown, don't look well. Is there any chance of saving these trees?

Did you gather up as much fertilizer as possible? Did you flush the soil with lots of water?

The easiest way to know if the Cypress are dead is to scratch some of the brown limbs and trunk. If the layer under the bark is green, the plants are still alive. If its brown or as hard as a rock, the those parts are dead.