Its APRIL 15 2010. Is it still okay to prune about 12 inches off the top of thuja trees that have about two feet of space between them. The shrubs range from four feet to ten feet in height - Central Vancouver Island. I have been noticing that the thuja hedges (Mid Vancouver Island) seem to be rather dry looking this spring - not as vital looking as previous years. Not much new green growth visible. Trimming from last year has left the foliage on top with a little tinge of brown on the green. Can a person fertilize individual thuja shrubs (or parts of a hedge) so some can grow faster and catch up with those that already tower over them? How do you prevent the browning and death of some of these individual thuja shrubs?