Bioengineering Materials

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Soil bioengineering is the term for using plant material to arrest and prevent slope and streambank failure and ero­sion. The roots and stems serve as structural and mechanical elements in a slope protection system. Live cuttings and rooted plants are embedded in the ground in various arrays to serve as soil reinforcements, hydraulic drains, and barriers to earth movement.

Once established, this living material effectively controls several stabilization and erosion control problems by binding the soil with its root system and creating a natural vegetative cover. Bioengineered sites are self-repairing and have the advantage of blending with natural surroundings.

Bioengineering Pricing

Green plant next to water
Live stakes installed and sprouting new growth

Bioengineering materials and stream restoration techniques

Ernst Conservation Seeds is an experienced producer of common and specialized live soil bioengineering materials. We understand the unique needs of bioengineering site construction. Our material is grown, processed, and delivered to minimize on-site installation labor and maximize survival and quick establishment.

Helpful tips of a Bioengineering project

Ernst Conservation Seeds’ bioengineering products are dormant live material. There­fore, if installation cannot take place immediately upon arrival at the site, these prod­ucts must be stored properly. Place in a cool, wet place out of direct sunlight, such as under straw or burlap. Open any pallets, boxes, and plastic bags so the material can be watered thoroughly. Do not allow the material to dry out. Soaking before planting significantly increases survival and growth rate.

For best survivability, the material should be planted during the dormant season, No­vember 1st to April 30th. We do not guarantee any of our bioengineering material from May 1st to October 31st.

Overseeding and mulching a completed bioengineered project with the appropriate seed mixes protects the soil surface from erosion while adding biodiversity to the site.

Pallet of branches
Bioengineering materials ready to be shipped
  • Stakes are dormant, live woody cuttings of a species with the branches trimmed off. Live staking performs an important function in creating a root mat that stabilizes the soil by reinforcing and binding soil particles together. Stake establishment also improves aesthetics and provides a habitat for wildlife. Live stakes may be used on their own to secure other bioengineering materials or as an anchor for erosion control and geo-fabric. Stakes or poles may also be inserted or driven through openings in rock structures, such as gabions, riprap, and other retaining structures.

    Cross section diagram

    Installation notes

    Install stakes during their dormancy (late fall to early spring). Do not allow the material to dry out. Soaking be­fore planting significantly increases survival and growth rate. Drive a pilot hole into firm soil and plant at right angles (buds oriented up) with at least two-thirds of its length underground. Plant stakes randomly or 3′-6′ apart on triangular spacing. Tamp the soil down around the cuttings before watering. Irrigation may be necessary if a long dry spell or hot weather is expected following installation.

    Live stake sizes

    1/4″-1″ diameter; 2′-4′ lengths.

  • Brush (branch) layers are living branches placed on a terrace along the contours of a streambank and interspersed between layers of soil. This technique is used to repair a slump or gully and is most effective for revegetating scour holes.

    Brush layers diagram

    Installation notes

    Brush (branch) layers are placed on ter­raced benches with two-thirds of the basal material tilted into the slope and covered with soil. Branches should protrude beyond the face of the terrace. Before installing, soil terraces can be addition­ally protected by putting down geo-fabric. Starting at the bottom of the slope, secondary brush (branch) layers may be added every 3′-4′ proceeding up the slope. Straw mulching the finished surface is recommended for moisture retention and additional erosion control. Planting should be during the dormant season.

    Brush Layer sizes

    3 linear ft per bundle, 28-36 branches per bundle; available in 3′-6′ bundles.

  • Brush mattresses are living branches layered 1-2 branches thick in a crisscross pattern on a streambank to form a living ground cover. The mattress formed protects the bank surface until the branches root and native vegetation is es­tablished. This living system normally roots in the entire bank face, encouraging natural infiltration and immediately acting as a sediment trap.

    Brush mattresses diagram

    Installation notes

    Place material with the basal ends located toward the bottom of the slope. Using 3′ square spacing, drive dead wedge stakes into the plant material. Stretch wire or biodegradable twine or rope diagonally around the dead stakes and finish driving the stakes in to tighten the wire, twine, or rope and secure the mattress. Place a thin layer of soil over the entire area to encourage rooting. Irrigation is necessary immediately following installation.

    Brush Mattresses sizes

    1/4″-3″ diameter x random length x 1-2 or 3-4 branches thick.

  • Wattles or fascines are living branches bound together in long tubular bundles. When placed in shallow trenches across the slope of a bank, these structures provide protection from erosion and create a sediment trap that provides immediate bank support even prior to root growth. Once established, this live rooting material grows into a living fence-like erosion barrier. Within one growing season, roots and shoots grow along the entire length of the structure and quickly stabilize the bank.

    Sticks wrapped together
    A 5′ wattle ready to ship.

    Installation notes

    This technique is simple, effective, and installed with little site disturbance. Material is placed in 6″ wide trenches on banks or slopes parallel to the stream contour and partially covered with soil. Wedge-like dead stakes secure them in place at 2′-3′ intervals. Live stakes may also be used in conjunction with dead stakes to secure the material. Straw mulching the site following installation retains moisture and reduces surface erosion. Irrigation is necessary after installation if the soil is dry.

    Wattle/Fascine sizes

    6′ or 8′ lengths are recommended for ease of handling; available in the following diameters: 4″-5″, 6″-8″, 9″-12″ (custom lengths and diameters are available).

  • Dead wedge stakes are pieces of hardwood cut into long wedg­es to secure wattles, brush mattresses, and other applications of soil bioengineering and erosion control measures.

    Wooden wedges

    Stake sizes

    1-1/4″ x 3-1/4″ x 2-1/2′ long.

  • Whips are slender, live woody shrub material well-suited for very moist areas of stream edges, commonly used in con­junction with gabion structures, riprap, and geo-fabric.

    Installation notes

    Push whips into the ground as far as they will go without breaking. At least two-thirds of the whip should be covered with soil. Whips may be installed either by laying them on an angle or planting them erect in the soil. When using whips with hard structures, be sure they are long enough to reach into the soil and moisture behind or below the structure. (Example: If installing whips through riprap, consider the 3′ depth; therefore, install a 6′ whip at least 2′ into the moist soil behind the stone and 1′ above the surface of the riprap).

    Live Whip sizes

    3/8″-1″ diameter; 4′-6′ lengths.

Bioengineering Materials Inquiry

Please let us know about your bioengineering project and we will follow up with more information.

DISCLAIMER: The information in this review of practices is the result of more than 50 years of experience in seed production. Ernst Conservation Seeds has been supplying seeds and consulting in the reseeding of tens of thousands of acres of roadsides, surface mined lands, conservation, and restoration sites in eastern North America, as well as growing and supplying seed and consulting in the planting of hundreds of thousands of acres of CRP/CREP-related areas for erosion control and wildlife habitat. All of these practices are opinion only and our best advice as a result of these experiences. These recommendations do not cover all the conditions that will be encountered in the field. All of the information is for individual consideration. Ernst Conservation Seeds is not responsible for conditions that will be encountered in individual situations. The use of brand names does not represent our endorsement of a specific product; rather, it represents our experience only and has not necessarily been replicated in peer-reviewed research. The use of chemical pest control agents is subject to manufacturers’ instructions and labeling, as well as federal, state, and local regulations.
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