Section 8     Temporary Seeding

8.1 General

The specifications of Section 8 shall apply to the seeding of erosion control groundcover which will be in place for eight (8) months or less, and which will be replaced within eight (8) months of establishment with permanent groundcover, or other structures, etc. All labor, equipment, and materials required for the completion of Section 8 shall be furnished by the seeding contractor, unless specified otherwise.

8.2 Soil Testing and Preparation

8.2a Soil Testing

.1. Requirements. When a temporary seeding is expected to perform its erosion control function for more than six (6) months, tests for soil acidity (pH) and soil soluble salts shall be taken. If, because of contractual obligations or other compelling reasons, there is insufficient time to conduct and evaluate soil test results before seeding operations are begun, a soil sample shall be collected at the time of seeding, and the soil tests shall be conducted and evaluated as soon as possible thereafter. Because saline soils, acidic cuts, and dredge soils are frequently encountered in Maryland, it is recommended that soil tests be taken for as many different soil lots or sites as there are within the seeding site. Soil testing is not required prior to the establishment of temporary groundcover seedings which are expected to remain in place for less than four (4) months. However, when the seeding contractor knows or suspects that a temporary seeding may be jeopardized by adverse soil conditions present at the seeding site, tests for soil acidity (pH) and soil soluble salts shall be taken.

.2. Minimum soil test values. Temporary seedings shall not be established where the soil acidity (pH) is below pH 4.5 or above pH 8.0, or where soluble salts exceed 750 ppm. Soil modifications may be made before seeding, at the time of seeding, or at any time after seeding, as long as the function of the temporary seeding is not reduced by adverse soil conditions. If soil pH is below pH 4.5, see Table A, below, and add the amount of limestone necessary to raise soil pH to 4.5 to 8.0. If soil pH is above pH 8.0, see Table B, below, and add the amount of sulfur necessary to lower the soil pH to 4.5 to 8.0. A soil acidity of pH 6.5 is ideal. If soluble salts exceed 750 ppm, see Table C, below, and add the amount of gypsum necessary to reduce soluble salts below 750 ppm.

Table A
Pounds of Limestone to Add per 1000 ft2
To Raise Soil pH to 6.5

Soil Texture Class

Original pH  Sand  Loam Clay
4.8 85 140 200
5.0 75  125 175
5.2 65 110 150
5.4 55 95 125
5.6 45 80 100
5.8 35 65 80
6.0 25 50 60
6.2 15 35 40
6.4 5 15 20

Note: Table A shall be used only for limestone which meets the specifications Section 4.3

Table B
Pounds of Elemental Sulfur to Add per 1000 ft2
To Reduce Soil pH to 6.5

Soil Texture

Original pH Sandy Soil  Clay Soil
7.5 10-15 20-25
8.0 25-35 35-50
8.5 35-50 40-50

Note: Table B shall be used only for elemental sulfur which meets the specifications of Section 4.4

Table C
Pounds of Gypsum to Add per 1000 ft2
To Reduce Soluble Salts to Recommended Levels

Original Salts Level

 Pounds Gypsum

millisiemens  parts per million (ppm)  per 1000 ft2
8 2500 320
7 1800 230
6 1250 160
5 700 80
4.5

550

40


Note: Table C shall only be used for finely ground gypsum which meets the Specifications of Section 4.5

8.2b Soil Preparation

The soil of temporary seeding areas shall be loosened to a minimum average depth of 2.0 inches in sites where the slope is shallower than 3:1. In sites where the slope is 3:1 or steeper, the soil shall be loosened to a depth of 0.5 to 1.0 inch. The soil shall be loosened with rototillers, disk harrows, chisel plows, rippers, bulldozers, or other soil preparation equipment which shall leave the soil with an irregular open surface. Bulldozers which are used to loosen the soil surface shall leave the surface with an open irregular surface, and with track ridges which run parallel to the slope.

8.3 Fertilizer

8.3a General

When soil tests have been performed, as specified in Section 8.2a, temporary seeding sites shall receive fertilizer at rates which are in accordance with recommendations made by the University of Maryland Soil Testing Laboratory, or another accredited soil test laboratory which performed the soil tests.

8.3b Starter Fertilizer

In the absence of soil tests, and without regard to any established nutrient requirements, a starter fertilizer may be applied to the temporary seeding site, so that not more than 1.0 pound of nitrogen (N) per 1000 ft2 (45 pounds N per acre), and 2.0 pounds of phosphorus (P2O5) per 1000 ft2 (90 pounds P2O5 per acre), and 2.0 pounds of potassium (K2O) per 1000 ft2 (90 pounds K2O per acre), which may be applied up to 10 days before seeding, at the time of seeding, or up to 5 days after seeding.

8.4 Seed Mixtures

8.4a Species For Temporary Seeding

The following species shall be used in temporary seedings, as appropriate, according to Table G.

Cool Season Grasses: Barley, Cereal Rye, Oats, Wheat, Annual Ryegrass
Warm Season Grasses: Foxtail Millet, Weeping lovegrass

8.4b Temporary Seeding Rates, Depths, and Seeding Dates

Table G, below, shows specifications for temporary seed mixes and their use.

Table G
Temporary Seed Rate, Seed Depth, Hardiness Zone, and Seeding Dates

Species Minimum Seed Rate

Seed Depth

USDA Zone

Seeding Times

Bu./A. Lb./A. Lb./1000 ft2 (inches)
Barley 2.0 96 2.20 1.0-2.0 7a and 7b 2/1 - 4/30 and 8/15 - 10/15
6b 3/1 - 4/30 and 8/15 - 10/15
6a and 5b 3/15 - 5/31 and 8/1 - 10/31
Oats 3.0 96 2.20 1.0-2.0 7a and 7b 2/1 - 4/30 and
6b 3/1 - 4/30 and
6a and 5b 3/15 - 5/31 and
Rye 2.0 112 2.57 1.0-2.0 7a and 7b 2/1 - 4/30 and 8/15 - 11/30
6b 3/1 - 4/30 and 8/15 - 11/15
6a and 5b 3/15 - 5/31 and 8/1 - 10/31
Wheat 2.0 120 2.75 1.0-2.0 7a and 7b 2/1 - 4/30 and 8/15 - 11/30
6b 3/1 - 4/30 and 8/15 - 11/15
6a and 5b 3/15 - 5/31 and 8/1 - 10/31
Barley or 142.5 3.27 0.75-1.25 7a and 7b 2/1 - 10/15
Rye and 7.5 0.17 6b 3/1 - 10/15
Foxtail Millet 6a and 5b 3/15 - 10/31
Weeping 4 0.09 0.25-0.50 7a and 7b 5/1 - 8/14
Lovegrass or 6b 5/1 - 8/14
Lehmann Lovegrass 6a and 5b 6/1 - 7/31
Annual 50 1.15 0.25-0.50 7a and 7b 2/1 - 4/30 and 8/15 - 11/1
Ryegrass 6b 3/1 - 4/30 and 8/15 - 11/1
6a and 5b 3/15 - 5/31 and 8/1 - 8/15
Foxtail Millet 10 0.23 0.25-0.50 7a and 7b 5/1 - 8/14
6b 5/1 - 8/14
6a and 5b 6/1 - 7/31

 

8.5 Seeding Methods

8.5a Choice of Seeding Methods

Seed and/or mulch for temporary groundcover seedings shall be applied with cultipacker seeders, spreaders, drills, or hydraulic seeders which ensure uniform distribution and coverage at specified rates. The seeding contractor shall select one of the methods described in Section 8.5b (hydraulic seeding), or 8.5c (dry seeding) for all temporary groundcover seedings.

8.5b Hydraulic Seeding

.1. Definition. Hydraulic seeding methods shall be defined to include the distribution of seed through a pump under pressure with equipment that continuously agitates the seed in a suspension (slurry) of water. In addition to seed and water, the hydraulic seeding slurry may also include limestone and/or fertilizer and/or hydraulic mulch. Hydraulic mulch products shall be composed of wood fiber, wood cellulose fiber, or a combination of these materials (wood fiber + wood cellulose fiber hydraulic mulch).

.2. Fertilizer and limestone. When fertilizer and/or limestone is included in the hydraulic seeding slurry with seed, the maximum combined weight of fertilizer and limestone included in the hydraulic seeding slurry shall not exceed 150 pounds per 100 gallons of water. When fertilizer is applied with seed in the hydraulic seeding slurry, the amount of soluble nitrogen fertilizer (actual N) included shall not exceed 90 pounds per acre. Also, the amount of phosphorus (as P2O5) shall not exceed 180 pounds per acre, and the amount of potassium (as K2O) shall not exceed 180 pounds per acre. Limestone included with seed in the hydraulic seeding slurry shall be applied at a maximum rate of 2,200 pounds of limestone per acre. Pulverized or pelletized limestone shall be the only limestone used for this application: neither granulated limestone, nor burnt lime, nor hydrated lime shall be used for hydraulic seeding. When soil test results recommend the application of more than 2,200 lbs. of limestone per acre, or more than 90 lbs. of soluble nitrogen per acre, or more than 180 lbs. of phosphorus per acre, or more than 180 lbs. of potassium per acre, the required amounts of these materials which are in excess of these limits shall be applied with appropriate spreader equipment in one or more separate operations (see Section 8.5c).

8.5c Dry Seeding

.1. Definition. Dry seeding methods shall include the use of cultipacker spreaders, drop seeders, broadcast spreaders, slot seeders, or other types of seeders and spreaders which do not include water when they distribute seed. The seed distributed by dry seeding methods shall be uniformly spread and incorporated into the soil to an average depth of 1/8 -1/4 inch below the soil surface. Areas which receive seed by dry seeding methods shall be rolled with a weighted roller after seeding, so that the seed is pressed firmly into the soil.

.2. Fertilizer and limestone. Fertilizer and limestone shall be applied according to soil tests and recommendations of the U.M. soil testing Laboratory, or other soil test lab, or a starter fertilizer may be applied according to Section 8.3. Applications of limestone which exceed 50 lbs. per 1000 ft2 (2,200 lbs. per acre) shall be incorporated into the soil before seeding operations are begun, as specified in Section 4.2; limestone applications which are less than these maximum amounts may be applied at any time before seeding, at the time of seeding, or up to five (5) days after the completion of seeding operations.

8.6 Seed Mulches

8.6a Seed Mulch Categories

Seed mulches for temporary groundcover seedings shall consist of straw or hay, wood fiber, wood cellulose fiber, or wood fiber + wood cellulose fiber. Erosion control matting products shall not be used for temporary seedings, unless specified otherwise.

8.6b Straw, Hay, Wood Fiber, Wood Cellulose Fiber Products

The composition of straw and hay used as seed mulch for temporary groundcover seeding shall conform to the definitions of Section 7.2e and 7.2f. Straw and hay used for temporary groundcover seeding shall be free of the seeds, rhizomes, or other viable parts of these weeds:

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

Straw and hay shall be applied according to the provisions of Section 7.4c.1., and be anchored, as appropriate, according to the provisions of Section 7.4c.2.-.7. Mulch nettings shall not be used for temporary groundcover seedings Wood fiber, wood cellulose fiber, and wood fiber + wood cellulose fiber hydraulic mulch products shall conform to the definitions of Section 7.2a-c, and be applied according to the provisions of Section 7.4a-b.

8.7 Site Protection, Damage Repair, and Reseeding

8.7a Site Protection

It shall be the responsibility of the seeding contractor to install signs, flagging, etc. at the perimeter of all temporary groundcover seeding sites immediately after their completion, 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 temporary groundcover seeding site that is damaged by the entrance of such traffic when the site has been appropriately designated with signs, flagging, etc. its perimeter (see Disclaimer, Section 8.10).

8.7b Repairs to Damaged Areas

.1. General. It shall be the responsibility of the seeding contractor to apply effective temporary seeding and erosion control mulch materials, and to ensure that such 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 incursion of unwanted grass seed.

.2. Repairs to temporary groundcover seeding sites. In the event of heavy rain, wind, or other natural event that causes damage to the temporary groundcover seeding 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 regrading, reseeding, and remulching, so that the temporary groundcover seeding site is restored to a condition acceptable according to the specifications of Section 8.

.3. Repairs to nearby areas. In the event of heavy rain, etc. that causes damage to the temporary groundcover seeding site, as described in Section 8.7b.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 repairs to the temporary groundcover seeding site, or to any nearby areas, when there is evidence that the failure of the seeding 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 temporary groundcover seeding 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 temporary groundcover seeding site and nearby areas.

8.8 Clean Up

Grading stakes, stones, trash, and other debris which may hinder maintenance or future soil preparation and seeding of the temporary groundcover seeding site shall be removed from the site when seeding operations are completed. Soil, straw, hay, hydraulic fiber mulch, fertilizer, compost, limestone, elemental sulfur, gypsum, and other debris shall be removed from paved areas soon as possible after spreading and seeding operations are completed. Clean up operations shall be completed before acceptance is given.

8.9 Acceptance

8.9 a Acceptance of Materials

The seeding contractor shall inform all affected parties of the composition of the seed mixes, seed blends, fertilizer, compost, limestone, elemental sulfur, gypsum, and seed mulch materials which are intended for application at the temporary groundcover seeding 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 spreading or seeding operations are begun. Labels and other material identification pertaining to the materials which are applied shall be retained by the seeding contractor for a minimum of 90 days after the completion of spreading and seeding operations.

8.9b 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 temporary groundcover seeding site upon the satisfactory completion of each Subsection of Section 8. The temporary groundcover seeding 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 8 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.

8.10 Disclaimer

8.10a Damage

The seeding contractor shall not be financially or otherwise held liable to repair damages incurred to the temporary groundcover seeding 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, remulch, repair or otherwise amend the seeding site as a result of the use of topsoil, fertilizer, soil amendments, seed, 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 products, when they are applied by the seeding contractor in good faith, in accordance with their label or description.

8.10b Hazards

It shall be recognized that the temporary groundcover seeding 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 temporary groundcover seeding 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.

8.11 Guarantee

8.11a General Guarantee

The seeding contractor shall guarantee that all seed mixtures, seed mulches, fertilizer, compost limestone, elemental sulfur, gypsum, and application methods used at the seeding site shall be selected and used under the supervision of the seeding contractor according to the specifications of Section 4, Section 7, and Section 8, unless specified otherwise, and that those materials and methods shall be appropriate for the site and the intended use of the site.

8.11b Term and Limitations of Guarantee

Because the seeding contractor shall have no responsibility for providing irrigation or other post-seeding care to the temporary groundcover seeding site, and because temporary groundcover seeding is often undertaken at times outside those specified in Table G in Section 8.4, the seeding contractor shall not guarantee the development of living groundcover at the temporary seeding site within any timeframe, unless specified otherwise.

8.11c Special Guarantees

The seeding contractor shall guarantee that appropriate efforts shall be taken to control soil erosion and the loss of seed and mulch materials which are applied by the seeding contractor according to the specifications of Section 8. 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 temporary groundcover seeding; however, the seeding contractor shall not be obliged to identify, or report upon, or render any inadequacies fit to perform any particular purpose.

8.12 Payment

The seeding contractor shall give notification upon the completion of Section 8; the temporary groundcover seeding 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 8, and may seek appropriate legal remedies.