A landscaper planted a chamaecyparis nootkatensis pendula in my garden 2 summers ago and this year it is starting to yellow from the trunk out pretty well all over except at the very top. It is approximately 6'high. I have kept the ground well watered but not wet. Could it have been badly planted? How does one check this? (I'm thinking, root girdling). The site is quite exposed (we can get winds as high as 60km/hr with 90/100kms gusts during the winter). Maybe this is too harsh an environment for this tree?