Hornbeam hedge - thin spots and privacy questions
In 2012 I planted a hornbeam hedge to provide privacy from a footpath which runs adjacent to my property. I planted a staggered double row of whips. They have all grown well. I pruned using secateurs in the early years and now prune carefully with hand shears. I think I have followed all the advice carefully, but I have two problems.
1. In parts the hedge is thin, so when it is in full leaf it doesn't always provide the desired privacy. There are 'holes', gaps at different heights which I can't see how to fill.
2. Although beautiful in summer, in winter the brown leaves fall away quite quickly, so there is no privacy. Can I plant (say) privet or some other evergreen hedge within / alongside the hornbeam, so that the hornbeam is still visible yet the privacy is ensured ?
As usual all advice gratefully received !