This releases any remaining seed to fall on the snow. Permafrost prevents water percolation, which often results in the development of extensive muskegs and bogs. It is apparently more common within black spruce types than white spruce. Surface layers often have large accumulations of organic matter. Swamps, fens, wet meadows, swales, and low gradient streams often flood seasonally.
Bog birch is a deciduous shrub.
The male catkins begin blooming in the spring before or as the leaves expand. The majority of seed are dispersed in the fall.