Restoring Stream Banks With Willows
Restoring Stream Banks With Willows
Willows along a stream serve many important functions. They provide shade and cover for stream life and improve water quality by absorbing and storing chemicals. Their abilities to withstand flooding, to stabilize soils and to grow quickly in saturated areas make them ideal for revegetating stream banks.
Establishing willow cuttings, stakes and/or wattles on a stream bank will benefit you and the stream. The most appropriate material and method to use will depend upon stream size and planning location.
Willows growing in a nearby area, with similar soil and moisture conditions as your problem area, should be used as planting stock to help increase tree survival.
If plants are purchased from a nursery, you should buy cuttings and not rooted seedlings. Also, select a native species to enhance survival and decrease competition with other plants.
Recommended species include:
1. Black willow (Salix nigra)
2. Sand bar willow (S. interior)
3. Meadow willow (S. petiolaris),
4. Heart-leaved willow (S. rigida)
5. Ward's willow (S. Carolinina)
Collect and plant the willows during the dormant season. Willows planted in the spring before the buds swell seem to do the best. When storing or transporting plants, keep them cool and slightly moist.
Willow Cuttings
Cuttings are used on small streams where flooding and erosion is minimal. This material is easy to obtain, requires few tools and little labor to plant.
1. Cut 1/2 to 1 inch diameter plants or stems and remove all lateral branches.
2. Cut the stems with a knife or pruning shears into 12- to 24-inch lengths.
3. Make a horizontal cut on the end which will remain exposed and a 45-degree angle cut on the end to be planted. This will prevent you from planting them upside down. (Note: Buds on plant should face up.)
4. Push cutting directly into soil or produce a pilot hole by pounding a piece of metal rebar into the soil and then push the cutting into the hole. A planting (dibble) bar may also be used. Plant so that only a few inches remain exposed.
Willow Stakes
Use stakes where materials need to be driven deeper to improve moisture supply (to the stakes).
1. Cut 1- to 3-inch diameter stems into 18- to 36-inch lengths with a hand saw or chainsaw and remove all lateral stems. (Note: Using an axe or knife to cut the stems may damage the plant.)
2.Use dibble bar or dive stake with mallet until approximately 3 to 6 inches remain exposed or to refusal. Do not force and split stake.
Willow Posts
Posts can also be used to revegetate stream banks. They are most appropriate in situations where a stable moisture supply is deep in the soil and willow materials need to be driven deeper to reach it. This is a very labor intensive method, but posts can withstand relatively high flows.
1. Cut 3- to 6-inch diameter trees into 6- to 8-foot lengths with a chainsaw and remove all lateral branches. Sharpen bottom end to ease planting and score 12 to 14 inches.
2. Set posts in post holes or drive with post driver so that at least half of the post is buried. Posts must be set deep enough to maintain contact with the water table, but not so deep that they are completely submerged in water year-round.
3. The damaged top few inches of each post should be cut after planting if posts were driven.
Wattles
Use wattles in slow-moving water areas to trap sediments and revegetate banks. This method is more labor-intensive than planting cuttings or stakes.
1. Cut 1 1/2 inch or less diameter stems into a minimum of 3-foot lengths and remove all lateral branches.
2. Bundle stems with ends alternated. The bundle should be 1 to 2 feet longer than the longest stem cut.
3. Tightly compress the bundle to a diameter of 8 to 10 inches and tie with two wraps of twine every 10 to 15 inches.
4. Beginning at the toe, dig a horizontal trench 8 to 10 inches wide by 5 inches deep. Do not dig the trench more than one hour prior to planting the wattle to minimize soil drying.
5. Drive a vertical stake (2 to 3 feet long) on downhill side of the trench every 2 feet.
6. Place wattles in the trench and drive 2- to 3-foot-long stakes through the bundle every 3 feet.
7. Cover with soil and tamp wattle so that no more than 20 percent of the wattle is exposed.
A combination of these methods may be needed based on the characteristics of the stream and its banks.
Proper maintenance will be needed to attain long-term success. Protect young, growing willows from livestock. Also, avoid herbicide treatments on planted areas.
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. It is merely a tool to help mend problem areas. If you have further questions, please contact your local Missouri Department of Conservation Office.
Contact us at:
Missouri Department of Conservation
P.O. Box 180
Jefferson City, MO 65102-0180
