One of the most common small trees in a stream is a willow.
Willows provide shade and cover for stream life and improve water quality by absorbing and storing chemicals. From a stream bank stabilization standpoint, willows have a unique ability to withstand flooding. They also grow quickly in saturated areas, which makes them ideal for re-vegetating stream banks.
Stream bank erosion can be a major problem for landowners. One of the easiest and cheapest ways to solve stream bank erosion problems is to re-vegetate with trees and shrubs. Willows are ideal for these kinds of projects.
Most streams and creeks have willows already growing on the banks. Try to find willows growing close to the problem site. Using willows that are growing in similar soil and moisture conditions will help increase tree survival. Willows will grow from cuttings. Cut stakes off of a nearby willow trees and stick them in the ground and they will grow.
Collect and plant the willows during the dormant season, generally February through April. When storing or transporting willows, keep them cool and slightly moist. Willow cuttings can be up to 3 inches in diameter and 18 to 24 inches long. Remove all lateral branches. When planting, push cuttings directly into soil so that only a few inches remain exposed. The deeper you plant the cuttings, the better chance of survival.
Make sure to not plant the willow upside down. This is a mistake that some people make because there are no leaves or lateral limbs on the plant.
When planting in gravel or hard clay, use a rubber mallet to drive the stake in. You can create a pilot hole by pounding a piece of metal rebar into the soil and then push the cutting into the hole. If you split the top of the plant while driving, remove the split portion with a cutting shear. To stabilize an eroding stream bank with willows, start at the toe of the bank, where the bank meets the stream channel. This is the area that will need the most protection. Proper maintenance will be needed to attain long-term success. Protect young, growing willows from livestock. Also, avoid herbicide treatment on planted areas.
If willows are not available on site, you can purchase them from a private nursery or from the Missouri Department of Conservation nursery in Licking, Mo. Order forms are available in late November and recommended species include black willow, sand bar willow, meadow willow, heart-leaved willow and Ward's willow.
Planting willows along and on stream banks provides a number of benefits to the fragile stream environment and the surrounding land. However, this technique does not replace the need for responsible stream corridor management such as maintaining a permanent corridor of trees along streams.
For information, contact the Missouri Department of Conservation at (573) 290-5730.
Brad Propst is a fisheries biologist for the Missouri Department of Conservation.