The upper leaves and shoots of our box hedge have, quite suddenly, developed white (chlorotic) patches. The patches are all crescent-shaped: most leaves have a green tip folloed by a cresent white shape, and green again at the base. The arms of the crescent extend down the edges of the leaf towards the base and often curl inwards. New shoots have wilted and are dying. Picture attached. Our weather has been strange with a week of above average temperatures followed by a one night frost and now cool sunny weather. We live near Washington D.C. Thanks, 7104eversfield.