Section 7     Seed Mulches

7.1 General

The specifications of Section 7 shall apply to the selection and use of seed mulches for turfgrass seedings. All labor, equipment, and materials required for the completion of Section 7 shall be furnished by the seeding contractor, unless specified otherwise.

7.2 Seed Mulch Materials

7.2a Wood Fiber Hydraulic Mulch Definition

Wood fiber hydraulic mulch products shall consist of specially prepared wood that has been processed to a uniform fibrous state, and shall be packaged for sale as a hydraulic mulch for use with hydraulic seeding equipment. The wood fibers of wood fiber hydraulic mulch products shall have a length of approximately 0.5 inches (13 millimeters) and a diameter of approximately 0.0625 inches (1.5 millimeters). The wood fibers shall be dyed green, or the wood fiber hydraulic mulch product shall be mixed with a dye in a separate operation that will provide appropriate color to aid visual inspection of the material when it is spread. Wood fiber hydraulic mulch products shall have a pH range of pH 4.0-8.5, and an ash content which shall not exceed 7.0% of the product by weight. Wood fiber hydraulic mulch products shall contain no materials or chemicals in concentrations which inhibit the germination or growth of grasses, forbs, meadow flowers, or other seedlings when they are applied according to the manufacturers label directions. Wood fiber hydraulic mulch products shall be capable of remaining in suspension with water under agitation so that such products shall readily blend with seed, fertilizer, and limestone to form a uniform slurry. Wood fiber hydraulic mulch products shall have a minimum water holding capacity of 1 gallon of water (8 lbs.) per pound of wood fiber hydraulic mulch, and shall be rewettable and permeable to water after they have been applied.

7.2b Wood Cellulose Fiber Hydraulic Mulch Definition

Wood cellulose fiber hydraulic mulch products shall consist of specially prepared newspaper, newsprint, magazines, or other paper that has been processed to a uniform fibrous state, and shall be packaged for sale as a hydraulic mulch for use with hydraulic seeding equipment. The wood cellulose fiber hydraulic mulch may be derived from recycled materials, or be newly manufactured. The wood cellulose fibers shall be dyed green, or the wood cellulose fiber hydraulic mulch product shall be mixed with a dye in a separate operation that will provide appropriate color to aid visual inspection of the material when it is spread. Wood cellulose fiber hydraulic mulch products shall have a pH range of pH 4.0-8.5, and an ash content which shall not exceed 7.0% of the product by weight. Wood cellulose fiber hydraulic mulch products shall contain no materials or chemicals in concentrations which inhibit the germination or growth of grasses, forbs, meadow flowers, or other seedlings when they are applied according to the manufacturers label directions. Wood cellulose fiber hydraulic mulch products shall be capable of remaining in suspension (slurry) with water under agitation so that such products shall readily blend with seed, fertilizer, and limestone to form a uniform slurry. Wood cellulose fiber hydraulic mulch products shall have a minimum water holding capacity of 900% (90% when expressed as a ratio), and shall be rewettable and permeable to water after they have been applied.

7.2c Wood Fiber + Wood Cellulose Fiber Hydraulic Mulch Definition

Wood fiber + wood cellulose fiber hydraulic mulch products shall consist of wood fibers in combination with wood cellulose fibers derived from newspaper, newsprint, magazines, or other paper in a fixed combination, such as 70%-30%, etc. The wood fiber + wood cellulose fiber hydraulic mulch may be derived from recycled materials, or be newly manufactured. Both the wood fiber and the wood cellulose fiber materials shall be specially prepared and processed to a uniform fibrous state, and shall be packaged for sale as a hydraulic mulch for use with hydraulic seeding equipment. The wood fibers and wood cellulose fibers shall be dyed green, or the wood fiber + wood cellulose fiber hydraulic mulch product shall be mixed with a dye in a separate operation that will provide appropriate color to aid visual inspection of the material when it is spread. Wood fiber + wood cellulose fiber hydraulic mulch products shall have a pH range of pH 4.0-8.5, and an ash content which shall not exceed 7.0% of the product by weight. Wood fiber + wood cellulose fiber hydraulic mulch products shall contain no materials or chemicals in concentrations which inhibit the germination or growth of grasses, forbs, meadow flowers, or other seedlings when they are applied according to the manufacturers label directions. Wood fiber + wood cellulose fiber hydraulic mulch products shall be capable of remaining in suspension (slurry) with water under agitation so that the product shall readily blend with seed, fertilizer, and limestone to form a uniform slurry. Wood fiber + wood cellulose fiber hydraulic mulches shall have a minimum water holding capacity of 1 gallon of water (8 lbs.) per pound of wood fiber + wood cellulose fiber hydraulic mulch, and shall be rewettable and permeable to water after they have been applied.

7.2d Erosion Control Blanket Definition

Erosion control blankets, also known as stabilization matting products, shall have a uniform thickness and distribution of natural or biodegradable synthetic fibers or cords. Erosion control blankets shall freely allow the penetration and percolation of water, as well as the upward growth and development of seedlings of the plant species which they cover. Erosion control blankets shall contain no materials or chemicals in concentrations which inhibit the germination or growth of grasses, forbs, meadow flowers, or other seedlings when they are applied according to the manufacturers label directions. Erosion control blankets may be manufactured in any of several different forms: as a felted sheet, or a fine or coarsely woven fabric, or a loose aggregation of fibers (e.g., wood excelsior) that is held together with natural fibers or biodegradable polymer fiber netting on the top surface and/or bottom surface of its structure. Erosion control blankets shall resist rotting or decay for a minimum of six months.

7.2e Straw Definition

.1. Classes of straw.

Class AA Straw shall be specially grown for use as a seed mulch, and shall be composed entirely of the air-dried stems and leaves of native grasses such as little bluestem, broomsedge, or other species which are compatible with the meadow seeding sites where it will be used. Class AA straw may contain any amount of the viable seed of the native grass species from which it is derived. Class AA straw is the recommended straw mulch for dry meadow seeding sites, and may be used for temporary seeding, or erosion control seeding, or flower meadow seeding, or wet meadow seeding. Class AA straw shall not be used as a seed mulch for general turfgrass areas or rough turfgrass areas.

Class A Straw shall be specially grown for use as a seed mulch, and shall be entirely composed of the air-dried stems and leaves of wheat, barley, oats, or cereal rye. Class A straw shall be cut and baled before its seed has matured, or shall be very thoroughly threshed. Class A straw shall be guaranteed by the producer of the straw to contain a maximum of 1.0 ounce of viable wheat, barley, oats, or cereal rye seed per standard small bale of straw (approx. 40 lbs. of straw per bale). Class A straw shall be the only straw used for mulching general turfgrass areas (see Section 5.5a), and may be used as a seed mulch for rough turfgrass areas, or temporary seeding, or erosion control seeding, or flower meadow seeding, or wet meadow seeding, or dry meadow seeding.

Class B Straw shall be entirely composed of the air-dried stems and leaves of wheat, barley, oats, or cereal rye. Class B straw shall be thoroughly threshed so that it contains more than 1.0 ounce, but less than 8.0 ounces (up to 0.5 lbs.) of viable wheat, barley, oats, or cereal rye seed per standard small bale of straw (approx. 40 lbs. of straw per bale). Class B straw may be used as a seed mulch for rough turfgrass areas, or temporary seeding, or erosion control seeding, or flower meadow seeding (not recommended), or wet meadow seeding (not recommended). Class B straw shall not be used as a seed mulch for general turfgrass areas, nor dry meadow seeding.

Class C Straw shall be entirely composed of the air-dried stems and leaves of threshed wheat, barley, oats, or cereal rye. Class C straw shall contain more than 8.0 ounces (0.5 pound) of viable wheat, barley, oats, or cereal rye seed per standard small bale of straw (approx. 40 lbs. of straw per bale). Class C straw may be used as a seed mulch for temporary seeding or erosion control seeding. Class C straw shall not be used as a seed mulch for general turfgrass areas, nor rough turfgrass areas, nor flower meadow seeding, nor wet meadow seeding, nor dry meadow seeding.

.2. Physical condition. Straw shall consist of the air-dried stems and leaves of native grasses such as broomsedge or little bluestem (Class AA), or shall consist of the air-dried stems and leaves of wheat, oats, barley, or cereal rye (Class A, B, and C). All classes of straw shall be bright in color, and shall not be wet, musty, moldy, caked, decayed, or dusty. Straw should be easily loosened when removed from the bale, and able to be uniformly spread by hand or with the use of a straw blower.

.3. Weed content. All classes of straw (AA, A, B, and C) shall be free of the seeds, rhizomes, or other viable parts of these species:

Balloonvine Canada Thistle Johnsongrass & hybrids Serrated Tussock
Bermudagrass Curly Thistle Musk Thistle Sicklepod
Bindweed Dodder Phragmites Spurred Anoda
Corn cockle Giant Foxtail Plumeless Thistle Wild Garlic
Cocklebur Horse Nettle Quackgrass Wild Onion

.4. Chemical residues. Straw shall contain no materials or chemicals in concentrations which inhibit the germination or growth of grasses, forbs, meadow flowers, or other seedlings when the straw is applied according to rates and methods specified in Section 7. Except as noted in Section 7.2e.1., above, straw may be used as a seed mulch material for general turfgrass seeding, rough turfgrass seeding, temporary seeding, erosion control groundcover seeding, flower meadow seeding, dry meadow seeding, wet meadow seeding, and highway seeding.

7.2f Hay Definition

.1. Physical condition. Hay shall include the air dried stems and leaves of forage grasses or forage legumes. Hay shall not be wet, musty, moldy, caked, decayed, or dusty. Where the establishment of forage grasses or forage legumes from seed which may be present in hay is not objectionable, such as temporary seeding sites and erosion control seeding sites, hay may be used as a seed mulch material. Hay shall not be used as a mulch for general turfgrass areas, nor rough turfgrass areas, nor flower meadow seeding, nor dry meadow seeding, nor wet meadow seeding.

.2. Weed content. Hay shall be free of the seeds, rhizomes, or other viable parts of these species:

Balloonvine Canada Thistle Johnsongrass & hybrids Serrated Tussock
Bermudagrass Curly Thistle Musk Thistle Sicklepod
Bindweed Dodder Phragmites Spurred Anoda
Corn cockle Giant Foxtail Plumeless Thistle Wild Garlic
Cocklebur Horse Nettle Quackgrass Wild Onion

.3. Chemical residues. Hay shall contain no materials or chemicals in concentrations which inhibit the germination or growth of turfgrass, or other seedlings when the hay is applied according to the rates and methods specified in Section 7. Hay shall not be used as a seed mulch material for general turfgrass area seeding (e.g., home lawns) nor for flower meadow seeding, but may be used for rough turfgrass area seeding, temporary seeding, erosion control seeding, and highway seeding (as specified by MD-SHA).

7.3 Seed Mulch Material Accessories

7.3a Liquid Mulch Binder and/or Tackifier Definition

Liquid mulch binder and/or tackifier products may be either natural or synthetic in origin. Liquid mulch binder and/or tackifier products may be used to anchor straw or hay seed mulches in combination with wood cellulose fiber mulch or wood fiber + wood cellulose fiber mulch. The liquid mulch binder and/or tackifier products shall be applied according to the label directions of the manufacturer of the products, or as may be necessary to ensure that the straw or hay seed mulch is securely held in place, so that minimal amounts of seed and/or soil are permitted to erode from the seeding site.

7.3b Steel Staples

Steel staples shall be used to secure erosion control blankets to the soil surface. Staples shall be either of U or T shape. U shape staples shall be 11-gauge U-shaped wire, with width not less than 1.5 inches and length not less than 6.0 inches. T shape staples shall be 8-gauge T-shaped wire, with main leg not less than 8.0 inches long and secondary leg not less than 1.0 inch long and head not less than 4.0 inches wide. Steel staples shall be installed according to the label instructions of the manufacturer of the erosion control blanket, or as may be necessary to ensure that the erosion control blanket is securely held in place, so that minimal amounts of seed and/or soil are permitted to erode from the seeding site.

7.4 Mulch Application Procedures

7.4a Wood Fiber and/or Wood Cellulose Fiber Hydraulic Mulch Application

Wood fiber, wood cellulose fiber, and wood fiber + wood cellulose fiber products used as hydraulic mulches for turfgrass seeding shall be applied in accordance with the label directions of the manufacturer, so that a minimum of 80% of the soil surface is covered with hydraulic mulch, or as may be necessary to ensure that the wood fiber, wood cellulose fiber, or wood fiber + wood cellulose fiber hydraulic mulch is securely held in place, so that minimal amounts of seed and/or soil are permitted to erode from the seeding site, while still allowing the passage of emerging seedlings.

7.4b Erosion Control Blanket Application

Erosion control blanket products shall be applied over soil surface of the seeding site and secured to the soil with steel staples, according to the manufacturers label instructions. The edges of erosion control blankets shall be overlapped and stapled in place according to the label instructions of the manufacturer of the erosion control blanket, or as may be necessary to ensure erosion control blankets are securely held in place, so that minimal amounts of seed and/or soil are permitted to erode from the seeding site. Where slopes are 3:1 or steeper, the erosion control blankets shall be installed perpendicular to the slope of the seeding site and overlapped like roof shingles, so that the downslope edge of each blanket overlaps the upslope edge of the next blanket, from the top to the slope to the bottom of the slope.

7.4c Straw or Hay Application, Anchoring, and Binding

.1. General. Straw and hay seed mulches shall be spread uniformly over the soil surface at a rate of 1.0 to 2.0 tons per acre.. The straw or hay mulch shall cover a minimum of 80% of the soil surface in a layer from 0.5 to 1.5 inches thick, with a maximum of 10% of the soil surface covered with straw or hay mulch over 2.5 inches in thickness. When straw or hay mulch is secured into the soil with a mulch anchoring tool (straw crimper), the application rate of straw or hay mulch shall be increased to 2.5 tons per acre.

.2. Anchoring requirements. In sites where the effectiveness of straw or hay seed mulches may be reduced by wind or water erosion, straw or hay seed mulches shall be securely anchored to the soil as soon as possible after they are distributed over the soil surface, or before the first significant rainfall by one or more of the methods described in Section 7.4c.2. thru 7.4c.7. It shall be the responsibility of the seeding contractor to select and use those methods which best protect the soil from loss by erosion, and which ensure the most rapid and complete establishment of germinating seed.

.3. Anchoring with mulch anchoring tool. A mulch anchoring tool may be used to crimp or press straw or hay seed mulches into the soil, if such equipment is capable of crimping or pressing the straw or hay to a minimum average depth of 2.0 inches below the soil surface. Mulch anchoring tools shall not be used where slopes steeper than 3:1 may interfere with the safe or effective use of anchoring equipment.

.4. Anchoring with wood fiber hydraulic mulch. Wood fiber hydraulic mulch products (i.e., products which contain more than 70% wood fiber) shall not be used to anchor straw or hay seed mulches.

.5. Anchoring with wood cellulose fiber hydraulic mulch. Wood cellulose fiber hydraulic mulch products may be used to anchor straw or hay seed mulches when the wood cellulose fiber hydraulic mulch products are applied according to the manufacturers label directions or according to application rates and methods that ensure that the straw or hay seed mulch is firmly held from erosion while still allowing the passage of emerging seedlings.

.6. Anchoring with wood fiber + wood cellulose fiber hydraulic mulch. Products which combine wood fiber and wood cellulose fiber in a single hydraulic mulch product may be used to anchor straw or hay seed mulches when the wood fiber + wood cellulose fiber hydraulic mulch products are applied according to the manufacturers label directions or according to application rates and methods that ensure that the straw or hay seed mulch is firmly held from erosion while still allowing the passage of emerging seedlings.

.7. Anchoring with liquid mulch binder and/or tackifier. Liquid mulch binder and/or tackifier products may be used to anchor straw or hay seed mulches when the liquid mulch binder and/or tackifier products are applied according to the manufacturers label directions or according to application rates and methods that ensure that the straw or hay seed mulch is firmly held from erosion while still allowing the passage of emerging seedlings.

.8. Anchoring with mulch netting. Mulch netting products may be used to anchor straw or hay seed mulches when the mulch netting products are spread and stapled according to the manufacturers label directions or according to application rates and methods that ensure that the straw or hay seed mulch is firmly held from erosion while still allowing the passage of emerging seedlings.

7.5 Mulched Site Protection and Damage Repair

7.5a Site Protection

It shall be the responsibility of the seeding contractor to install signs, flagging, etc. at the perimeter of mulched sites immediately after the completion of mulching operations, which shall serve to notify foot and vehicular traffic that a sensitive area may be damaged by their entry. The seeding contractor shall not be financially or otherwise held liable to repair a mulched site that is damaged by the entrance of such traffic when the mulched site has been appropriately designated with signs, flagging, etc. at its perimeter (see Disclaimer, Section 7.8).

7.5b Erosion Protection and Damage Repair

.1. General. It shall be the responsibility of the seeding contractor to apply effective erosion control mulch materials, and to ensure that the mulch materials are secured to the soil so that they are not blown, washed, or otherwise removed from the site, and so that nearby streams and other areas shall be protected from soil, fertilizer, compost, and the introduction of unwanted grass seed.

.2. Repairs to mulched sites. In the event of heavy rain, wind, or other natural event that causes damage to the mulched site which is of a kind or type that may have been anticipated or prevented by the seeding contractor, such as through the use of mulch, staples, tackifier, etc., then the seeding contractor shall be obliged to make repairs limited to the damaged areas within the site, including reseeding, so that the mulched site is restored to a condition acceptable according to the specifications of Section 7.

.3. Repairs to nearby areas. In the event of heavy rain, etc. that causes damage to the mulched site, as described in Section 7.6b.2., above, and which also causes damage to nearby areas, as may be evidenced by soil deposition, straw deposition, etc. on the surfaces of the nearby areas, then the seeding contractor shall be obliged to make repairs to the damaged nearby areas, so that the nearby areas shall be restored to a condition substantially similar to their condition before the damaging event.

.4. Special limitations. The seeding contractor shall not be obliged, financially or otherwise, to regrade, reseed, remulch, or make any other repairs to the mulched site, or to any nearby areas, when there is evidence that the failure of the mulch application was substantially due to water, soil, or other materials which passed into the site from an area which was not stabilized or under the control or supervision of the seeding contractor. Examples of situations which shall void the responsibility of the seeding contractor to repair the mulched site and nearby areas shall include the failure of responsible parties to provide effective groundcover, spillways, drainage diversions, water settlements, silt fence, etc. for areas which drain into the site, which would have prevented significant damage to the mulched site and nearby areas.

7.6 Clean Up

Grading stakes, stones, trash, and other debris which may hinder the future maintenance of the newly mulched areas shall be removed from the site when mulching operations are completed. Soil, straw, hay, hydraulic fiber mulch, and other debris shall be removed from paved areas as soon as possible after mulching operations are completed. Clean up operations shall be completed before acceptance is given.

7.7 Acceptance

7.7a Acceptance of Materials

The seeding contractor shall inform all affected parties of the composition of the mulch materials which are intended for application at the mulched site before any of these materials are applied at the site; acknowledgment of acceptance of these materials shall be given by the owner, general contractor, landscape architect, or other person(s) authorized to make such a decision before mulching operations are begun. Labels and other material identification pertaining to the mulch materials which are applied shall be retained by the seeding contractor for a minimum of 90 days after the completion of mulching operations.

7.7b Acceptance of Performance

Acknowledgment of acceptable performance shall be given by the owner, general contractor, landscape architect, or other person(s) authorized to inspect the mulched site upon the satisfactory completion of each Subsection of Section 7. The mulched site shall be inspected within 24 hours of the completion of each Subsection, as indicated by the seeding contractor, unless specified otherwise. The seeding contractor shall give notification when all Subsections of Section 7 have been completed; final acceptance and payment shall be made within 24 hours of such notification, or within the time period specified in the contract.

7.8 Disclaimer

7.8a Damage

The seeding contractor shall not be financially or otherwise held liable to repair damages incurred to the mulched site as a result of materials not applied under the supervision of the seeding contractor, nor by vandalism, nor by acts of God. The seeding contractor shall not be financially or otherwise held liable to reseed, repair or otherwise amend the mulched site as a result of the use of seed mulch or other products which are labeled in error or which are otherwise not in accordance with the label or description provided with them by the manufacturer or distributor of the seed mulch or other products, when they are applied by the seeding contractor in good faith, in accordance with their label or description.

7.8b Hazards

It shall be recognized that the site is a construction zone not under the ownership or legal control of the seeding contractor, and as such may present hazards to persons or property which enter the site. The seeding contractor specifically disclaims any and all responsibility for the safety and security of persons or property which may enter the mulched site before the seeding contractor has begun work or when work is underway or at any time after work has been completed, and without regard to whether such entry is legal or otherwise. The seeding contractor shall assume no responsibility for personal injury or property damage, nor be subject to any claims of negligence, when the seeding contractor has performed work according to the specifications of MSA-GS-99, as mutually agreed, or has applied products or materials according to the recommendations of their manufacturer or distributor.

7.9 Guarantee

7.9a General Guarantee

The seeding contractor shall guarantee that all seed mulches and seed mulching methods shall be selected and used under the supervision of the seeding contractor according to the specifications of Section 7, unless specified otherwise, and that those seed mulches and seed mulching methods shall be appropriate for the site and the intended use of the site.

7.9b Term and Limitations of Guarantee

The seeding contractor shall guarantee that seed mulch materials, application methods, and anchoring methods shall control soil erosion for a minimum period of two (2) months after the seed mulch materials are applied.

7.9c Special Guarantees

The seeding contractor shall guarantee that appropriate efforts shall be taken to control soil erosion and the loss of mulch materials which are applied by the seeding contractor according to the specifications of Section 7. The seeding contractor shall endeavor to alert parties responsible for the control of water and/or soil erosion outside the seeding site which may adversely affect the success of the mulch application; however, the seeding contractor shall not be obliged to identify, or report upon, or render any inadequacies fit to perform any particular purpose.

7.10 Payment

The seeding contractor shall give notification upon the completion of Section 7; the site shall be inspected within 24 hours of such notification, and payment shall be made at that time, or as specified in the contract. When payment is not received within the specified time period, the seeding contractor may void any guarantees related to Section 7, and may seek appropriate legal remedies.