How to Prune a Birch Tree

Birch trees naturally have an open, airy branching structure.

Dozens of different species of birch trees (Betula spp.) are grown as ornamental accent or grove clusters in gardens in temperate regions around the world. Generally, birches do not need pruning unless to remove an errant branch or one that poses a safety risk. Limb dieback is less frequent when birch trees are growing in fertile, cool and moist soils where summers are not too hot and long. Mulches kept back from the trunk bases keep trees healthy to ward off any seasonal attacks by insects. The serious threat of the bronze birch borer can cause trees to die. Consult a local arborist or cooperative extension office for specific issues with birch trees in your region.

Things You'll Need

• Hand pruners (secateurs)
• Loppers
• Hand pruning saw

Instructions

1. Schedule any pruning activities on birch trees to take place in late winter to early spring. According to the U.S. Department of Agriculture, avoid pruning birches from May to August, when insect borers (especially the bronze birch borer) are most active. Pruning wounds made in summer are more readily invaded by the harmful borers, potentially leading to more branch dieback damage.

2. Evaluate the overall shape and form of the birch tree. Note if there are any dead branches or ones showing diseases. Mark these branches for removal. Remove these branches/twigs with a hand pruners, making the pruning cut 1/4 inch above a lower healthy branch junction or dormant bud or leaf.

3. Reduce the length or eliminate any branches that pose a safety hazard, such as low branches that could be walked into as they hang over a sidewalk. Branches that are larger than 1/2 to 3/4 inch in diameter are better removed by using a loppers or hand pruning saw rather than a pruners. Make pruning cuts flush against larger branches or the main trunk, about 1/4 to 1/2 inch away from the trunk's surface.

4. Remove any branches that are rubbing against each other or are growing across the middle of the tree's structure. Keep the healthier-looking or less-wounded branch of the two that are rubbing against each other. Make sure the branch that remains isn't one that grows across the center of the tree.

5. Allow pruning wounds to callus naturally. Do not apply paints or sealers to the wound. According to the U.S. Department of Agriculture's Forestry Service Division, applying such materials interferes with the natural protective resins and sap of the birch to seal off the wound.

Tips & Warnings

• Any diseased plant material removed from the birch tree should be discarded far from the tree. Birch borer-infested wood should be burned.

• Remember, birch trees naturally have a rather open branching structure, so do not prune to destroy this structure. Prune to maintain this feature and diminish the need for constant pruning. Pruning helps to create a strong-structured tree devoid of diseased or dead tissues.

• Regardless of pruning needs, never remove more than 25 percent of the foliage or branches in the canopy of a birch tree during any one-time pruning event each year.

References

• U.S. Department of Agriculture (Forest Service): How to Grow and Maintain a Healthy Birch Tree
• U.S. Department of Agriculture (Forest Service): How to Prune Trees
• University of Maine Cooperative Extension: Pruning Woody Landscape Plants

Resources

• Read this Article in Spanish