Willows absorb water and were introduced here from Europe to help control rivers and streams. They are often planted to stabilise river banks and provide shelter and shade, however in the wrong place they can spread quickly and take over.

The willow trees grow rapidly and spread through waterways, creating dense thickets and competing with natives as well as causing blockages and flooding. Seeds are spread by the wind and stem fragments are spread via water.

They are deciduous and can grow to around 7m high. They produce catkins, or flowers, from September to October and willow seed capsules contain lots of seeds. Willows tolerate all sorts of conditions including flooding and hot and cold temperatures, which means they do well in the Mackenzie Basin.