I have a line of Lilly Pilly's along my side fence planted about 10 years back to create some privacy from next door. They are probably over 10-12 metres high now but the bottom 2 metres are bare of leaves. My question is "If I cut along the line say 4 or 5 metres high will leaves start to grow under and fill up the 2 meters gap at the bottom and also grow high again"?