Thanks for the replies everyone!
@Xeramtheum - what is this feed you mentioned? I fertilize them with 10-10-10 a few times during the growing season, but I don't water them every day. Perhaps I will finally install that drip line I keep thinking about in my head.
Does the vine you mentioned stay green in the winter? Can it grow on a loose wire lattice? I can't make it tight, as the trees must have some room to sway in the breeze. How fast will it grow?
@greene - I live in Wake county, and according to the rules, the setback limits are 15', which is what he put his house at. I am not sure however on any ordinance regarding what trees can be planted where on the property line.
The leylands are only about 3-4' tall. Some don't get very much sun unfortunately and aren't growing much at all. I don't want to cut down any more trees to give them more light however. I feel that the lots are thinned out enough as is
The important ones are getting plenty of light however, and are showing signs of vertical progress.