The Mighty Birch Tree

Betula. The Mighty Birch Tree.

Mighty birch tree - A characteristic River birch favoring wet sites.

Birches (Betula spp.) have a long history of providing shade and beauty to the New York landscape with its unique bark color and texture characteristics, habit and form. Besides, birches have long held an honored place in American life and history from our recall of images of birch-bark canoes, basketball fans thrill to a game played on a birch-wood court and of course, birch beer.

The genus Betula contains 30 to 60 taxa growing in Asia [12], North America [4] and Europe [4]. They are rather short-lived as a woodland pioneer species widespread in the Northern Hemisphere, particularly in northern temperate and boreal climates. The birches are a broadleafed, deciduous hardwood tree within the Family Betulaceae. Betulaceae also include alders, hazels, and hornbeams and is closely related to the beech/oak family Fagaceae.

Of the numerous tree species two most common plantings as landscape ornamentals in our area are the River Birch (Betula nigra) and the White Birch (Betula papyrifera). Along with a praised amenity characteristic, birches have a very shallow root system and thereby vulnerable to impacts through extreme summer heat prompting a concern about long-term care and health.

Birch Planting & care

Post planting of birches requires care because of its shallow root system, need for moist soils and so that they are not exposed to the direct summer sun. So select your planting location very carefully. Mulching the tree root zone with a 3-4 inch depth of untreated wood mulch will help keep the soil temperature down, maintain moisture as well as cutting out on weeding. Birch trees flourish in slightly acidic soils. Fully mature birches under optimum conditions can grow upwards of 65 feet high a consideration should there be overhead electric wires.

Mighty birch tree - Birch deciduous leaf chatacteristic.      Mighty birch tree - Birch leaf minor.

Watch Out For the Bugs

Mighty birch tree - Bronze birch borer adult and two D-shaped exit holes.

Although a beautiful amenity tree, the birches as a group are prey to borers and other insects casino online and miscellaneous diseases. Here are a few;

Birch Leafminer, Fenusa pusilla is a larvae that burrows into birch leaves in search for nutrients. You can spot these larvae by small green spots on the leaf surface in the beginning of the summer season, in late May into June. If left untreated, these green spots will turn into dark brown splotches and patches on the leaves and can weaken and disfigure your tree, making it more susceptible According to research done in the year 1999, it has been found that . to other insects, such as the Bronze Birch Borer. http://www1.extension.umn.edu/garden/insects/find/birch-leafminers/

The Bronze Birch Borer, Agrilus anxius Gory is native to North America and within the US it is distributed from Maine, across the Great Lakes region to the Cascade Mountains of Oregon and Washington, and from Maryland to Kansas. Bronze Birch Borer is a Birch killer—a wood boring beetle that get into the Birch trees developing layers and interfere the sap flow. The first notable evidence of a borer problem is yellowing and stunted foliage. Borers also leave exit wounds on the bark that seem to go deep into the core of the tree. Paper birches are commonly attacked by this borer where River Birch is rarely.

Aphids are another common problem, sucking the sap out of the trees leaves, giving the Birch leaves a yellow tinge and causing them to disfigure. Indications are when the tree seems to be dripping sap onto the ground and severe “leaf-drop.” The sap is actually secretions from the aphids which attract ants, causing even more problems if left untreated.

Attention to Tree Health.

Mighty birch tree - Eye catching paper birch, and its papery bark characteristic.

Provide proper care, especially irrigation in order to keep plants vigorous and robust. A key is to prune and dispose of branches with foliage infested with insect larvae to, a.) restore the plant”s aesthetic appearance and b.) provide some level of pest control. Avoid excessive pruning (or de-branching) since pruning is “wounding” the tree.

Plant resistant species or varieties. If planting birch, plant least susceptible species. Some foliage miners can be controlled by natural enemies and conserve beneficials by avoiding broad-spectrum persistent insecticides.

Flora of North America. http://www.efloras.org/florataxon.aspx?flora_id=1&taxon_id=103887

Ball, J.; Simmons, G. 1980. The relationship be­tween bronze birch borer and birch dieback. Journal of Arboriculture. 6:309-314.

Katovich, S.; Wawrzynski, R.; Haugen, D.; Spears, B. 1997. How to grow and maintain a healthy birch tree. NA-FR-02-97. USDA Forest Serv., Northeastern Area State and Private Forestry, Newtown Square, PA. 21 p. http://www.na.fs.fed.us/spfo/pubs/fidls/bbb/bbb.pdf

Solomon, J.D. 1995. Guide to insect borers in North American broadleaf trees and shrubs. Ag­ric. Handb. 706. USDA Forest Serv., Washing­ton, DC. 735 p.

Glaeser Horticultural Consulting Inc is a New York State ISA Certified Arborist firm that specializes in evaluating and maintaining healthy Birch trees and all other trees. Please visit glaeserhortconsulting.com for further information on how GHC can protect your tree asset and investment.