It sounds like you have a good bit of land. If you don't want to go removing any of the existing trees, one way you can sort of cover your bases to ensure there will always be a decent screen there is to add more trees to it. What I suggested earlier only rather than remove anything just add another 30-40 or so feet of planting. With a solid row of trees, you're in trouble if something happens to just one tree. With multiple rows of mixed species, your bases are covered. In my opinion leyland cypress looks 10 times better than green giant, especially in the winter time. They hold their color 100%. But that isn't to say you shouldn't plant some. Mix up the planting. But don't think you're going to patch up the gap in the row with a green giant and expect it to blend in because it wont. Nor will a bald cypress for that matter. Then again you may not be as concerned with how it looks as you are about patching the hole. In that case go for it.

Very outdated thread but since it has been revived, some clarifications are in order. While the landscapers were definitely bumbling about with the care and storage of the trees after delivery and poor planting techniques, there is really no concern about the spacing. In fact. I'd say the comments about them being too close are coming from those with no experience in planting and maintaining a Leylandii hedge. " they would eventually choke each other out. " No, they won't!! Recommended spacing of Leyland cypress for a solid hedge is 3' to 6'. Lived next door to one for 10+ years with a 3' o.c. spacing and the trees did perfectly well and are still doing well in the 8 years or so since I moved. btw, the continuing slams against Leylands are typically unfounded. Yes, they do not fair well in all parts of the country and they are often grown rather haphazardly by less scrupulous growers/sellers but there is nothing inherently wrong with the tree itself. It does grow fast and it does grow large but can be maintained as a very tidy hedge at any height you want.

Sometimes you can damage them if you try to remove the snow. I suggest letting the snow melt naturally. Then prop them up, stake them, and they should be fine, as long as they didn't break. Even if some were uprooted, you can still restore the root ball, feed, water, mulch...and they will be OK. I know it can be hard to look at now, but by August it will be a distant memory. Back in 2003, we had 17 inches of heavy wet cement, and when I woke up, my young southern magnolia was "gone"---almost flattened. But it popped back very well and 7 years later is a brute of a tree.

no evergreen holds its leaves/needles forever ... the oldest and therefore interior leaves are always the ones shed ... in NORMAL shedding ... it can be significantly increased by transplanting .. and aftercare issues ... its a stress issue ... they are not hungry.. fert is not a response ... from the first pic.. thats what it looks like to me ... i cant see much in the second pic because of the bright sunshine ... and the only response would be proper watering for all of this year ... and they should be rather free range by next year ... ken look at the proper watering part, and mulch https://sites.google.com/site/tnarboretum/Home/planting-a-tree-or-shrub