Item No. 604

Seeding for Erosion Control

604.1 Description

This item shall consist of preparing a seed bed to the lines and grades indicated, sowing of seeds, fertilizing, mulching with straw, asphalt, cellulose fiver, wood fiber and other management practices along and across such areas as are indicated or as directed by the Engineer/Architect/Landscape Architect.

604.2  Submittals

The submittal requirements for this specification item shall include:

  A.      Identification of the type, source, mixture, PLS and rate of application of the seeding.

  B.     Type of mulch.

  C.     Type of tacking agent.

  D.     Type and rate of application of fertilizer.

604.3. Materials

A.   Seeds.  All seed must meet the requirements of the Texas Seed Law including the labeling requirements for showing pure live seed (PLS), name and type of seed.  The seed furnished shall be of the previous season's crop and the date of analysis shown on each bag shall be within nine months of the time of delivery to the project.  Each variety of seed shall be furnished and delivered in separate bags or containers.  A sample of each variety of seed shall be furnished for analysis and testing when directed by the Engineer or designated representative. 

 

The amount of seed planted per acre (hectare) shall be of the type specified in sections 604.5 and 604.6.

 

B.   Water.  Water shall be clean and free of industrial wastes and other substances harmful to the growth of grass or the area irrigated.

 

C.  Top Soil.  Topsoil shall conform to Standard Specification, "Borrow".

 

D.  Fertilizer. The fertilizer shall conform to Standard Specification, "Fertilizer".  The fertilizer used shall have an analysis of 15-15-15, homogeneous 13-13-13 or the analysis indicated.

E.   Straw Mulch or Hay Mulch.  Straw Mulch shall be oat, wheat, or rice straw.  Hay mulch shall be prairie grass, Bermuda grass, or other hay approved by the Engineer or designated representative.  The straw or hay shall be free of Johnson grass or other noxious weeds and foreign materials.  It shall be kept in a dry condition and shall not be molded or rotted.

F.   Tacking Agents.  The tacking agent shall be a biodegradable tacking agent, approved by the Engineer or designated representative.

 

G.  Cellulose Fiber Mulch (Natural Wood).  Cellulose Fiber Mulch shall be natural cellulose fiber mulch produced from grinding clean whole wood chips.  The mulch shall be designed for use in conventional mechanical planting, hydraulic planting of seed or hydraulic mulching of grass seed, either alone or with fertilizers and other additives.  The mulch shall be such, that when applied, the material shall form a strong, moisture-retaining mat without the need of an asphalt binder.

    

H.     Recycled Paper Mulch.  Recycled paper mulch shall be specifically manufactured from post-consumer paper and shall contain a minimum of 85% recycled paper content by weight, shall contain no more than 15% moisture and 1.6% ash, and shall contain no growth inhibiting material or weed seeds.  The recycled paper mulch shall be mixed with grass seed and fertilizer for hydro-seeding/mulching, erosion control, and a binder over straw mulch.  The mulch, when applied, shall form a strong, moisture-retaining mat of a green color without the need of an asphalt binder.

604.4  Construction Methods

A.   Preparing Seed Bed.  After the designated areas have been rough graded to the lines, grades and typical sections indicated in the Drawings or as provided for in other items of this contract and for any other soil area disturbed by the construction, a suitable seedbed shall be prepared.  The seedbed shall consist of a minimum of either 4 inches of approved topsoil or 4 inches of approved salvaged topsoil, cultivated and rolled sufficiently to reduce the soil to a state of good tilth, when the soil particles on the surface are small enough and lie closely enough together to prevent the seed from being covered too deeply for optimum germination.  The optimum depth for seeding shall be 1/4 inch. Water shall be gently applied as required to prepare the seedbed prior to the planting operation either by broadcast seeding or hydraulic planting.  Seeding shall be performed in accordance with the requirements hereinafter described.

 

B.   Watering.  All watering shall comply with City Ordinances.  Broadcast seeded areas shall immediately be watered with a minimum of 5 gallons of water per square yard or as needed and in the manner and quantity as directed by the Engineer or designated representative.  Hydraulic seeded areas and native grass seeded areas shall be watered commencing after the tackifier has dried with a minimum of 5 gallons of water per square yard or as needed to keep the seedbed in a wet condition favorable for the growth of grass.

 

Watering applications shall constantly maintain the seedbed in a wet condition favorable for the growth of grass.  Watering shall continue until the grass is uniformly 1 1/2 inches in height and accepted by the Engineer or designated representative.  Watering can be postponed immediately after a 1/2 inch or greater rainfall on the site but shall be resumed before the soil dries out.

604.5  Non-Native Seeding

 

A.   Method A - Broadcast Seeding.  The seed or seed mixture in the quantity specified shall be uniformly distributed over the prepared seedbed areas indicated on the Drawings or where directed by the Engineer or designated representative.  If the sowing of seed is by hand, rather than by mechanical methods, the seed shall be sown in two directions at right angles to each other.  If mechanical equipment is used, all varieties of seed, as well as fertilizer, may be distributed at the same time, provided that each component is uniformly applied at the specified rate.  After planting, the planted area shall be rolled with a corrugated roller of the "Cultipacker" type.  All rolling of the slope areas shall be on the contour.

 

Seed Mixture and Rate of Application for Broadcast Seeding:

From September 15 to March 1, seeding shall be with a combination of unhulled Bermuda Grass at a rate of 2 pounds per 1000 square feet and winter rye at a rate of 7 pounds per 1000 square feet that has a PLS (pure live seed or purity x germination) of 0.83. 

From March 1 to September 15, seeding shall be with hulled Bermuda Grass at a rate of 2 pounds per 1000 square feet with a PLS = 0.83.  Fertilizer shall be applied and shall conform, "Fertilizer".

 

B.   Method B - Hydraulic Planting.  The seedbed shall be prepared as specified above and hydraulic planting equipment, which is capable of placing all materials in a single operation, shall be used.

 

March 1 to September 15

 

Hydraulic planting mixture and minimum rate of application pounds per 1000 square feet:

 

Hulled Bermuda Seed
(PLS=0.83)

 

Fiber Mulch

Soil

Tackifier

Cellulose

Wood

 

1 Lbs/1000 ft2

45.9 Lbs/1000 ft2

 

1.4 Lbs/1000 ft2

 

57.4 Lbs/1000 ft2

1.5 Lbs/1000 ft2

 

     Water soluble fertilizer shall be added at a rate of 15 lbs. per 1000 square

     feet.

 

September 15 to March 1

 

Add 7 pounds per 1000 square feet of winter rye with a PLS = 0.83 to above mixture.  The fertilizer shall conform to Standard Specification, "Fertilizer".

 

604.6  Native Grass Seeding

The seedbed shall be prepared as specified above.  The seed mixture and the rate of application shall be as follows:

 

 

Description

Application rates

Lbs/1000 feet 2

Lometa Indiangrass

0.1

PremierSideoats grama

0.2

Green spangletop

0.1

Buffalo Grass

0.2

Little Bluestem

0.2

Blue grama grass

0.2

Total Seeding Rate

1.0

 

Species substitution as necessary due to availability shall be approved by the Engineer or designated representative.  Watering and fertilizer application shall follow procedures outlined above or as otherwise specified on the Drawings.

 

Seed shall be applied by broadcast or drill method and shall be distributed evenly over the topsoiled areas.  Mulching shall immediately follow seed application.

604.7.  Mulch

A.   Straw Mulch

        

Straw mulch shall be spread uniformly over the area indicated or as designated by the Engineer or designated representative at the rate of 2 to 2 1/2 tons of straw per acre.  The actual rate of application will be designated by the Engineer or designated representative.  Straw may be hand or machine placed and adequately secured.

 

B.   Fiber Mulch

 

Cellulose and wood fiber mulch shall be spread uniformly over the area indicated or as designated by the Engineer or designated representative at the rate of 45 to 80 lbs. per 1000 square feet.

 

C.  Recycled Paper Mulch

 

Recycled paper mulch shall be spread over the area indicated on the Drawings or as designated by the Engineer or designated representative at a rate that will provide 100% coverage.

 

D.  Shredded Brush Mulch

 

Small brush or tree limbs except Juniper, which have been shredded, may be used for mulching Native Grass seeding.

 

604.8  Measurement

Work and acceptable material for "Seeding for Erosion Control" will be measured by the square yard (meter: 1 meter equals 1.196 square yards) or by the acre (hectare: 1 hectare equals 2.471 acres), complete in place, with a minimum of 95 percent coverage with no bare areas exceeding 16 square feet (1.5 square meters) and a 1 1/2 inch (40 millimeters) stand of grass.  Bare areas shall be reprepared and reseeded as required to develop an acceptable stand of grass.

 

604.9  Payment

The work performed and materials furnished and measured will be paid for at the unit bid price for "Seeding for Erosion Control" of the method specified on the Drawings and type of mulch.   The unit bid price shall include full compensation for furnishing all materials, including all topsoil, water, seed, tackifier, fertilizer, or mulch and for performing all operations necessary to complete the work.

 

All fertilizer will be measured and paid for conforming to, "Fertilizer".

 

Payment will be made under one of the following:

 

Pay Item: Non-Native Seeding for Erosion Control Method, _______ Mulch Per Sq Yard.

Pay Item: Non-Native Seeding for Erosion Control Method, _______ Mulch Per Acre.

Pay Item:                            Mulch,                                                                Per Square Yard.

Pay Item:                            Mulch,                                                                            Per Acre.

 

End