Question
We have a single row of Leyland cypress varying from 5-8 years old, in the middle of the row 3 of the trees suddenly are turning yellow. They are on a slight slope and not around standing water.  These three are not growing at the same rate as trees on either side of them.  Should I fertilize and if so what should I use? About a month ago we did have a considerable amount of rain and did have standing water near all of the trees for a couple of days, since then it has been very dry.

Answer
Sounds like the trees got too much water from the standing rain water. Too much water can be as bad fro the tree as too little. I do not think I would not fertilize right now but just wait and see if the tree survived the standing water.
Trees need about 1 inch of water per week. If it is dry I would water--place a pan under the tree and turn the sprinkler on and when the pan has 1 inch of water in it stop. Do this once a week if it does not rain.