Question
Would a moderate Boron count (1.8ppm) in the irrigation water have a negative
effect on a new planting of Soquel Redwoods in Sonoma County?

Answer
Any effect from Boron should show up as yellowing of the needles around the tip of the needle at first, and the tip new needles would show signs of yellowing. Too much water would cause the needles to turn not on the edges of the needles but the entire needle. I would think you are over watering the tree. i would not water but once a week with 1 inch of water--place a pan under the tree and turn the sprinkler on and when the pan has 1 inch of water in it stop.