I planted 30 Japanese Boxwoods last year. I was told they do great in full sun. I have about 15 of them , now they are dying. The tips of the leaves are turning white. In time the whole leaf is white and then they die. Can they be saved? What is a good hardy shrub in full Florida sun?

While they will grow in full sun they do not do great, they actually prefer some shade. Read this and water Growing Boxwoods in the Landscape