Landscapers covet birch trees because of their distinctive bark characteristics and shaped, delicate foliage. However, they can be difficult species because they are prone to insect infestation and may decline in health before reaching maturity.
Birch trees should live for 40 to 50 years, but some die before turning 20. They have a shallow root system and need moist soil to thrive. Pruning birch trees will limit insect damage and promote a longer life.
Prune birch trees during the dormant growing season (fall or winter). Do not prune them between May and August because it is the bronze birch borer's flight period, which will attack fresh wounds. Aim to trim off less than 25 percent of the tree's canopy.
Climb the ladder and look through the canopy for broken, diseased or dead branches. Follow the limbs inside the canopy to the point where they meet healthy wood.
Focus on branches that have V-shaped connections with other limbs. These are prone to weakness and cracking. Limbs with U-shaped joints are stronger.
Mark unwanted limbs with a fluorescent spray paint. Spray the paint at the collar, which is the flared-out section of bark at the base of the branches.
Use a pruning saw to cut unwanted limbs next to the collar. This is the spot where tissue is most likely to regrow. Make sure not to leave stumps.
Prune older branches every few years. This will allow the tree to rejuvenate itself and focus on new growth.