Silver birch trees (Betula pendula) are deciduous trees desirable for their silvery-white bark and graceful form. Also called "European" or "white" birch trees, they are popular with home gardeners who want an easy-to-grow specimen tree. Unfortunately, their beauty comes with a price. Silver birch trees are often plagued by insect pest and disease problems that other, hardier trees do not suffer.
Silver birch trees can grow up to 100 feet tall in the wild, according to the University of Connecticut, but in cultivation they average around 50 feet tall and 30 feet wide. They have a pyramidal or oval shape. Betula pendula trees have slender branches and twigs, and showy, white bark with dark gray fissures. The leaves of the silver birch are green in the summer and golden in the fall.
Location and Climate
Silver birch trees grow best in climates with cool summers and cold or cool winters. These are identified as United States Department of Agriculture (USDA) Plant Hardiness Zones 3 through 6, according to the University of Florida. The trees should be located where they will receive full sun, and in well-draining soil.
Although birch trees grow readily—even on sandy or hard clay soils—they are not low-maintenance. These trees need regular watering and regular fertilization. The soil should be kept moist at all times. Fertilize in the spring and again in the summer with a balanced, all-purpose fertilizer. Apply according to the directions on the label for the size of your tree.
Birch trees also need to be pruned to develop a strong structure. Branches with narrow angles should be removed each spring. Home gardeners should also be aware of the insect problems these trees have and be prepared to treat the tree to prevent infestations.
All birch trees, including silver birches, can be infested by the bronze birch borer. This insect bores into the sapwood of the plant, killing it. As a result, the tree dies from the crown downward. Another insect that often plagues birch trees is the birch skeletonizer. The larvae of the beetle feeds on the leaves, turning them brown. Birch leaf miners also feed on the leaves of the silver birch. Home gardeners with these trees should spray their trees with an insecticide in the spring. Repeated applications may also be needed.
There are many cultivars of the silver birch tree. "Purple Splendor" has purple summer leaves that are very showy against the white bark. They turn greener in the summer heat, however. "Tristis" has weeping branches that droop gracefully almost to the ground from a narrow crown. "Golden Cloud" is a cultivar that features yellow leaves all year, except in the hottest climates, where they turn green in humid heat.