How are willow trees used for river bank protection?

By planting a pole or willow tree either alongside or close to the bank of a river. A willow tree will provide more effective erosion control if it is planted deeper than the eroding stream to provide a good anchorage point. The roots grow quite quickly in a moist environment and over several years growth will provide quite a substantial barrier to the eroding abilities of the river. After several years of growth the top portion of the willow can be partially cut and pushed into the stream to provide an even more effective barrier. This operation is called layering and the layered branches will send out roots when in contact with the water. It is advisable to tie each partially cut stem to avoid it breaking during an increase in water flow. After two to three years growth the layered willow is more able to anchor itself against flood flows. The important points when planting is to have water accessible to the willow and to plant the willow deeper than the eroding stream.