Looking for a plant that will grow on the edge of a river bed to help curb erosion?

There is a whole group of plants known as "marginals" which live on the edges of waterways around the world. What makes them unique is that they are well adapted to flood conditions when the waters are running high. During the dry season when the water drops, they are left on dry land. Marginals dry out and lie dormant until the waters rise again.

Many marginals share a unique ability to spread into large colonies through a vast network of underground roots. This web helps to bind the soil together on the banks of rivers. Good examples of this are cattails and horsetails. Horsetails are really attractive bamboo like rods that make fine water garden plants and problem solvers for soils that are too wet to support other plants.

But trees and shrubs can be equally valuable at bank and shore protection. Scrubby willows line riverbanks where their fine, fibrous roots are vital shore binders. The branches that sit in running water slow its velocity so there is less scouring, the action that causes erosion. The willows are a group that are the most coveted shore plants for gardens.

Because willows and poplars are such fast rooters, a whole riverbank can be planted with cuttings at the right time of year when they'll immediately root and go to work without risk of being swept away like a container grown plant.