True that, that is a major problem if the red cedars are dying. Though near a pond in the photo, looks like they are doing good because of moisture there, if indeed they are red cedars in that photo. Probably should have planted a fast growing deciduous row there too like bigfoot willow trees, so would already have a screen while the green giants are establishing and growing a little slower.
The thing about the Green Giant, is that it is a cross between west coast Thuja and Japanese Thuja, so is going to be a lot less tolerant to extremes than say red cedars. People have had some good growth with them, in certain areas of the country. In my local area, I keep trying and killing them, they seem to need winter protection here, rather than out in open.
