Betula pubescens

Downy birch

  • Glasbjörk (S)
  • Hieskoivu (FI)
  • Moorbirke (D)
  • Le bouleau (F)

Spread

The downy birch grows all over Finland except the the region north from Kittilä. Birch, pine and spruce are our most common tree species.

Location of growth

  • The downy birch grows well in a damp environment
  • It prospers in young nutrient-rich forests, swamps, trenches and near roads.
  • It handles pollution well and needs a lot of light
  • Birch survives stormy weather well thanks to its thick root.
  • Birch makes the soil it grows in better for other plantlife.
  • Fjeld birch is a subspecies of downy birch that has adapted to grow on fells of Finland.

 

Growth

  • The downy birch is often a multi-trunk tree that grows up to 20 meters tall
  • The bark of the birch tree is white and unique, except on the foot of the tree
  • The outer branches of the canopy are often hanging
  • The birch has a widespread root system.
  • The highest quality birch grows in soil high with nutrients.
  • The birch should be fallen as soon as possible when it reaches maturity so it doesn’t have time to rot.
  • The downy birch is smaller than the silver birch

The characteristics of wood

  • The fibers of downy birch are larger that the ones found in silver birch and thus it’s easier to split in two.
  • The wood is light and the fiber pattern is hard to make out.
  • The heartwood is not noticeably different than the surface wood
  • The wood is hard and elastic

  • It is important to dry birch well, because it rots very easily.
  • High quality log of birch is straight and at least 25cm thick. The trunk has to be smooth and it should not have cracks caused by low temperature or rot.
  • The dry lumber should weight 600kg/m3

Surface treatment

The wood samples have been surface treated as such:

  • Left, water-based acrylic lacquer
  • Center, no treatment
  • Right, two component catalystlacquer or oil

Radial cut

Tangential cut

Usage

  • There is a high demand for birch in the furniture industry and woodcraft.
  • Birch is the main raw material in the veneer industry.
  • The bark of birch is used by many craftsmen
  • The wood is also used by the paper industry
  • The sap of birch can be used as ingredient for various things, such as drinks