Silver Birch Trees in the United States

The silver birch grows across much of the U.S.

The silver birch tree, Betula pendula, is also referred to as the European white birch. A deciduous tree that sheds its leaves in the fall, the silver birch gains its name from the silvery-white color that adorns the tree's bark. It enjoys full sunshine and moist, well-drained soil, although it can grow in drier conditions.

Identification

The silver birch is considered hardy to USDA zones 2 through 7 in the U.S. and will grow in zones 8 through 9 but is short lived in those locales. It possesses a moderate to rapid rate of growth, which, according to the Arbor Day Foundation, denotes a tree that grows in excess of 24 inches annually. The silver birch typically achieves a height of between 40 and 50 feet with a canopy width of 10 to 20 feet.

Care and Maintenance

Not a low-maintenance tree, the silver birch requires more care and maintenance than most ornamental trees. It is susceptible to potentially fatal attack from the bronze birch borer, an insect that lays eggs within cracks in the tree, which then hatch into larvae. These small white worms bore into the bark of the tree, feeding as they create sawdust-filled tunnels under the bark. Damage will appear as raised bumps and typically begins at the top of the silver birch and works downward.

Pests

Bronze birch borer larvae normally appear in May and can be naturally controlled by ensuring that the European white birch is planted in a well-shaded area; the adult borer prefers to lay eggs on a tree that receives large amounts of sunshine. Application of chemical insecticide also is an effective management technique. Additionally, the tree suffers infestation from the birch leaf miner, but the damage caused by this insect is primarily aesthetic, appearing as a browning of the leaves.

Disease

Several forms of fungi result in canker diseases on a birch, reports the University of Florida Institute of Food and Agricultural Sciences. These diseases kill sapwood and bring forth sunken areas on the trunk and large branches. Avoiding wounding of the tree and keeping it healthy through proper fertilization and irrigation is the best preventive measure to avoid canker as no chemical control is effective against these fungi and disease.

References

• North Carolina State University: Betula pendula
• Arbor Day Foundation: About Growth Rate
• University of Florida Institute of Food and Agricultural Sciences: Betula pendula: European Birch