You can prune beech hedge trees while they are still young. Each time that you prune them, you encourage the hedge tree to grow and become bushier. During the first year of growth, the beech tree may have two trimmings. As you begin to prune a second time, you will see the beech tree beginning to bush out. When you prune the beech hedge, you are forcing the stems to become multi-branched. The more stems the beech hedge has, the more leaves it will have and the leaves will last longer into the winter.
Cut the tops of the beech hedge with secateurs . Remove 2 to 3 inches off each stem. This will force the buds to break and new shots to grow. Secateurs are more gentle on the foliage than hedge shears. A good time to do the first trim is in June.
Repeat the process again in that same year, once the hedge is growing and stems have increased in length by 3 to 4 inches. Remove half or less of the new growth with secateurs. The best time to do this is from July to November.
Prune the beech hedge again during the second year. This time, instead of cutting just the top growth, cut on the side shoots. This will encourage more growth, and more stems to form on the sides of the beech tree.
Repeat the pruning process again. This time you may be able to prune it three times during the year. You may repeat the process for a third year, but you don’t have to. If your beech tree is bushy enough on the second year, you can stop trimming.
Prune only once or twice a year to encourage new growth. This will give you a dense screen that is especially useful if you are growing the beech hedge as a living fence.