Environmental conditions are harsh for these plants, and survival is often difficult. Those that do survive can thrive and flourish in a sheltered location with good growing conditions. Such cedars may grow several inches each year, and will thus require pruning. If a plant has grown too large, prune it down to size in the spring, before growth starts. Take special care not to remove too much growth from the outside of the plant at this time.
All conifers lose their oldest needles or leaves, which are towards the centre of the tree.
If most of the green growth is pruned off the outer part of a branch, it will be left virtually bare. The virtually bare branch will seldom produce new growth and it will likely die. Any amount of pruning to downsize a cedar will inevitably make it look somewhat unattractive until it has had a chance to fill in, which can take a few years. The tree will gradually fill in on top and continue growing up. If you must reduce the tree's height further, stake the top branches into an upright position so that the top will fill in.