I have planted a hedge 100' feet long that consists of two staggered rows of thuja plicata spaced 2.5' apart and each tree spaced 2.5' apart. They are now approximately six feet tall and I have not done any pruning to date. I am thinking I need to start do some pruning so that it will be a thick hedge. When mature, I will want the hedge to be approximately 7' x 7' tall. I am thinking I should prune the end of branches protruding out from the trunk so that they are not more 12 - 15" from the trunk. I am thinking this will make the side shoots / branches grow out / thicken. Am I on the right track? I am thinking of doing this in April to take advantage of this year's new growth. I know this species of a hedge is always going to be work, but I wanted to use the seedlings of native species that were growing on my property (5 acres).
For a dense sheared hedge you should have started when they were small and sheared every year afterward. Now they are almost the size you want them to remain. (Note that you will have to leave a little new growth on every time you shear, so that there is going to be some size increase each time). Shear the outer shell of foliage during late spring-early summer. Do not cut back into bare, nearly bare or otherwise lightly furnished wood.
