A row of about 20 Leyland Cyprus along our back yard separates us from a 3 story medical office building for privacy. They are about 25-30 feet tall, about 15 years old, and about 8 feet apart. Over the years the bottom 4-5 feet of branches have died-out making quite a gap up to the top of the 6-foot privacy fence. I guess it's due to the mostly being in the shade. What can we plant in between them that will grow up to maybe 10-15 feet tall and fill out to take up space? We have thought about Wax Myrtle, non-sticker holly trees, Aucuba Japonica, Japanese Privet, and some others. Does anyone have any ideas? Thanks.