75 Ft. of Canadian Hemlock or American Arborvitae?
We need a privacy and wind screen for our back and side yard. The back is 75 ft. long and side is 40. The back corner of the yard slopes away from the house, so I want something tall enough in that corner, that will provide privacy for the deck, but not too tall to block the beautiful view of hills beyond. A mature height of 15' or so. The other two ends of the hedge need be only 6-8'.
A straight hedge would be quite formal. I prefer to plant groupings, but I don't want to make it look choppy or too random.
My two top choices right now are Canadian Hemlock (how tall does it get?) and American Arborvitae (grows to 18').
1. Which would you choose of those two?
2. If I use a combination of both, should I add some more variety in my shrub choices? (mostly fast-growing evergreens)
3. Advice on how to devise groupings? I have a lot of long space to fill. Mostly full sun, average soil, lots of wind, zone 5-6.