212.01 212-1 SECTION 212 SEEDING, FERTILIZER, SOIL CONDITIONER, AND SODDING DESCRIPTION
212.01 This work consists of soil preparation, application of fertilizer , soil conditioners, or
both, and furnishing and placing seed and sod. The work shall be per the Contract and accepted horticultural practices. MATERIALS
212.02 Seed, Soil Conditioners, Fertilizers, and Sod.
a.Seed. All seed shall be furnished in bags or containers clearly labeled to show the name and address of the supplier , the seed name, the lot number , net weight, origin, the percent of weed seed content, the guaranteed percentage of purity and germination, pounds of pure live seed (PLS) of each seed species, and the total pounds of PLS in the container. All seeds shall be free from noxious weed seeds per current state and local lists and as indicated in Section 213. The Contractor shall furnish to the Engineer a signed statement certifying that the seed is from a lot that has been tested by a recognized laboratory for seed testing within thirteen months before the date of seeding. The Engineer may obtain seed samples from the seed equipment, furnished bags, or containers to test seed for species identification, purity, and germination. Seed tested and found to be less than 10 percent of the labeled certifi ed PLS and different than the specified species will not be accepted. Seed that has become wet, moldy, or damaged in transit or in storage will not be accepted. Seed types and amount of PLS required per acre shall be provided per the Contract. Seed and seed labels shall conform to all current State and Federal regulations and will be subject to the testing provisions of the Association of Official Seed Analysis. Computations for quantity of seed required on the project shall include the percent of purity and percent of germination. The formula used for determining the quantity of PLS shall be: Bulk Pounds of Seed Species • ( Percent Purity • Percent Germination) = Pounds of PLS
b.Soil Conditioners and Fertilizer.
1.Fertilizer: Fertilizer (plant nutrients) shall conform to the applicable State fertilizer laws. It shall be uniform in composition, dry, and free flowing, and shall be delivered to the site in the original, unopened containers, each bearing the manufacturer's guaranteed analysis. Fertilizer that becomes caked or damaged will not be accepted. 212.02 212-2 2. Soil Conditioner: Soil conditioner shall consist of compost, biological nutrient, biological culture or humic acid-based material. Humic acid-based material (Humate) shall include the following:
A.A pH of 3 to 5.
B.Maximum 20 percent inert ingredient.
C.Minimum 80 percent organic matter with 40 percent minimum humic acid. Compost shall be weed –free, organic compost derived from a variety of feed stocks including agricultural, biosolids, forestry, food, leaf and yard trimmings, manure, tree wood with no substances toxic to plants. Material shall be aerobically composted in a facility permitted by the Colorado Department of Public Health and Environment (CDPHE) to produce or sell compost per House Bill (HB) 1181. The Contractor shall submit a copy of this permit to the Engineer for approval and the project records. The compos t shall be tested per the U.S. Composting Council’s Test Methods for Examining of Composting and Compost (TMECC ) manual. The compost manufacturer shall be a participating member of in the U.S. Composting Council’s Seal of Testing Assurance Program (STA). The Contractor shall provide a participation certificate and test data on a Compost Technical Data Sheet. 212.02 212-3 Compost shall have the following physical properties: Table 212-1 COMPOST PHYSICAL PROPERTIES Compost Parameters Reported as Requirement Test Method pH pH units 6.0 – 8.5 TMECC 04.11 -A Soluble Salts (Electrical Conductivity) dS m-1 or mmhos cm- 1 Maximum 10 dS/m TMECC 04.10- A Moisture Content %, wet weight basis 30 – 60% TMECC 03.09 -A Organic Matter Content %, dry weight basis 30 – 65% TMECC 05.07- A Particle Size ( sieve sizes) %, dry weight basis for each sieve fraction Passing 1 inch – 100% 1/2 inch – 95% TMECC 02.02- B Man-made Inert Contamination %, dry weight basis < 1% TMECC 03.08- A Stability (Respirometry) mg CO2- C per g TS per day mg CO2- C per g OM per day 8 or below TMECC 05.08- B Select Pathogens (PASS/FAIL) Limits: Salmonella <3 MPN/4grams of TS, or Coliform Bacteria <1000 MPN/gram Pass TMECC 07.01- B Fecal Coliforms, or
07.02 Salmonella
Trace Metals (PASS/FAIL) Limits (mg kg -1, dw basis): As 41, Cd 39, Cu 1500, Pb 300, Hg 17, Ni 420, Se 100, Zn 2800 Pass TMECC 04.06 Maturity (Bioassay) Percent Emergence %, (average) > 80% TMECC 05.05 -A Relative Seedling Vigor %, (average) > 80% Table 212 -1 Notes: The Contractor shall provide a CTR per subsection 106.13 confirming the material has been tested per TMECC. 212.03 212-4 (c) Sod. Sod shall be nursery grown and 99 percent weed free. Species shall be as shown on the plans. Other sod types may be used only if approved in writing by the Engineer. The one percent allowable weeds shall not include any undesirable perennial or annual grasses, or plants defined as noxious by current State statute. Soil thickness of sod cuts shall not be less than 3/4 inch nor more than 1 inch. Sod shall be cut in uniform strips with minimum dimensions of 18 inches in width and 48 inches in length. The Contractor shall submit a sample of the sod proposed for use, which shall serve as a standard. Any sod furnished, whether in place or not, that is not up to the standard of the sample may be rejected. Sod that was cut more than 24 hours before installation shall not be used. Each load of sod shall be accompanied by a certificate from the grower stating the type of sod and the date and time of cutting. CONSTRUCTION REQUIREMENTS
212.03 Seeding Seasons. Seeding in areas that are not irrigated shall be restricted
according to the following timetable and requirements . Table 212- 2 SEEDING SEASON TIMETABLE AND REQUIREMENTS Areas other than the Western Slope Zone Spring Seeding Fall Seeding Below 6000 feet Spring thaw to June 1 September 15 until consistent ground freeze 6000 to 7000 feet Spring thaw to June 1 September 1 until consistent ground freeze 7000 to 8000 feet Spring thaw to July 15 August 1 until consistent ground freeze Above 8000 feet Spring thaw to consistent ground freeze Western Slope Zone Spring Seeding Fall Seeding Below 6000 feet Spring thaw to May 1 August 1 until consistent ground freeze 6000 to 7000 feet Spring thaw to June 1 September 1 until consistent ground freeze 212.04 212-5 (1) “Spring thaw ” shall be defined as the earliest date in a new calendar year that seed can be buried 1/2 inch into the surface soil (topsoil) thru normal drill seeding methods.
2.“Consistent ground freeze ” shall be defined as that time during the fall months that the surface soil (topsoil), due to freeze conditi ons, prevents burying the seed 1/2 inch thru normal drill seeding operations. Seed shall not be sown, drilled, or planted when the surface soil or topsoil is in a frozen or crusted state. Seeding accomplished outside the time periods listed above will be allowed only when ordered by the Engineer or when the Contractor's request is approved in writing. When requested by the Contractor, the Contractor must agree to perform the following work at no cost to the Department: reseed, remulch, and repair areas that fail to produce species indicated in the Contract. When seeding is ordered by the Engineer outside the time periods listed above, the cost of additional material will be paid for by the Department. The Contractor will not be responsible for failure of the seeded area to produce species indicated in the Con tract due to reasons beyond the control of the Contractor. The seeding, the soil conditioning, and the fertilizing application rate shall be as specified. The Engineer may establish test sections for adjusting the seeding and the fertilizing equipment to assure the specified rate. The Engineer may order equipment readjustment at any time. Seed, soil conditioner and fertilizer shall not be applied during inclement weather including rain and high winds, or when soil is frozen or soil moisture is too high to evenly incorporate seed, soil conditioner or fertilizer.
212.04 Lawn Grass Seeding . Lawn grass seeding shall be accomplished in the seeding seasons
described in subsection 212.03.
a.Soil Preparation . Preparatory to seeding lawn grass, irregularities in the ground surface, except the saucers for trees and shrubs, shall be removed. Measures shall be taken to prevent the formation of low places and pockets where water will stand. Immediately before seeding, the ground surface shall be tilled or hand worked into an even and loose seedbed to a depth of 4 inches, free of clods, sticks, stones, debris, concrete, and asphalt in excess of 2 inches in any dimension and brought to the desired line and grade.
b.Fertilizing and Soil Conditioning . The first application of fertilizer, soil conditioner, or both shall be incorporated into the soil before seeding, and shall consist of a soil conditioner, commercial fertilizer, or both as designated in the Contract. Fertilizer called for on the plans shall be worked into the top 4 inches of soil at the rate specified in the contract. Biological nutrient, c ulture or humic acid -based material called for on the plans shall be applied in a uniform application onto the soil service. Organic amendments shall be applied uniformly over the soil surface and incorporated into the top 6 inches of soil. The second application of fertilizer shall consist of a fertilizer having an available nutrient analysis of 20 -10-5 applied at the rate of 100 lbs. per acre. It shall be uniformly broadcast over the seeded area three weeks after germination or emergence. T he area shall then be thoroughly soaked with water to a depth of 1 inch. Fertilizer shall not be applied when the application will damage the new lawn. 212.05 212-6 (c) Seeding . After the surface is raked and rolled, the seed shall be drilled or br oadcast and raked into the top 1/4 inch of soil. Seeding shall be accomplished by mechanical landscape type drills. Broadcast type seeders or hydraulic seeding will be permitted only on small areas not accessible to drills. Seed shall not be drilled or broadcast during windy weather or whe n the ground is frozen or untillable. All loose exposed rock larger than 2 inches shall be removed from slopes that are to be seeded by drilling. Hydraulic seeding equipment shall include a pump capable of being operated at 100 gallons per minute and at 100 pounds per square inch pressure, unless otherwise directed. The equipment shall have a nozzle adaptable to hydraulic seeding requirements. Storage tanks shall have a means of estimating the volume used or remaining in the tank.
212.05 Sodding .
a.Soil Preparation . Preparatory to sodding, the ground shall be tilled or hand worked into an even and loose sod bed to a depth of 4 inches, and irregularities in the ground surface shall be removed. Sticks, stones, debris, clods, asphalt, concrete, and other material more than 2 inches in any dimension shall be removed. Any depressions or variances from a smooth grade shall be corrected. Areas to be sodded shall be smooth before any sodding is done.
b.Sodding . The sod shall be laid by staggering joints with all edges touching. On slopes, the sod shall run approximately parallel to the slope contours. Where the sod abuts a drop inlet, the subgrade shall be adjusted so that the sod shall be 1 1/2 inch below the top of the inlet. Within one hour after the sod is laid and fertilized it shall be watered. After watering the sod shall be permitted to dry to the point where it is still wet enough for effective rolling. It shall then be rolled in two directions with a lawn roller weighin g at least 150 pounds.
c.Fertilizing and Soil Conditioning . Before laying sod, the 4 inches of subsoil underlying the sod shall be treated by tilling in fertilizer , soil conditioner, or both. The rate of application shall be as designated in the Contract. Fertilizer called for on the plans shall be worked into the top 4 inches of soil at the rate specified in the contract. Biological nutrient, culture or humic acid -based material called for on the plans shall be applied uniformly onto the soil surface. Organic amendments sha ll be applied uniformly over the soil surface and incorporated into the top 6 inches of soil. After laying, the sod shall be fertilized with a fertilizer having an available nutrient analysis of 20 -10-5 at the rate of 200 pounds per acre. Fertilizer shall not be applied when the application will damage the sod.
212.06 Native Seeding . Areas that are unirrigated shall be seeded per subsection 212.03.
a.Soil Preparation . Slopes flatter than 2:1, shall be tilled into an even and loose seed bed 4 inches deep. Slopes 2:1 or steeper shall be left in a roughened condition. Slopes shall be free of clods, sticks, stones, debris, concrete, and asphalt in excess of 4 inches in a ny dimension and brought to the desired line and grade.
b.Fertilizing and Soil Conditioning . Before seeding, fertilizer, soil conditioner, or both shall be applied. The fertilizer and soil conditioner type and rate of application shall be as designated in the Contract. Fertilizer called for on the plans shall be worked into the top 4 inches of soil at the rate specified in the contract. Biological nutrient, culture or humic 212.07 212-7 acid-based material called for on the plans shall be applied in a uniform application onto the soil service. Organic amendments shall be applied uniformly over the soil surface and incorporated into the top 6 inches of soil. No measurable quantity of organic amendment shall be present on the surface after incorporation.
c.Seeding . Seeding shall be accomplished within 24 hours of tilling or scarifying to make special seed bed preparation unnecessary. The seeding application rate shall be as designated in the Contract. All slopes flatter than 2:1 shall be seeded by mechanical power drawn drills followed by packer wheels or drag chains. Mechanical power drawn drills shall have depth bands set to maintai n a planting depth of at least 1/4 inch and shall be set to space the rows not more than 7 inches apart. Seed that is extremel y small shall be sowed from a separate hopper adjusted to the proper rate of application. If strips greater than 7 inches between the rows have been left unplanted or other areas skipped, the Engineer will require additional seeding at the Contractor's expense. When requested by the Contractor and approved by the Engineer, seeding may be accomplished by broadcast or hydraulic type seeders at twice the rate specified in the Contract at no additional cost to the project. All seed sown by broadcast -type seeders shall be "raked in" or covered with soil to a depth of at least 1/4 inch. Broadcasting seed will be permitted only on small areas not accessible to machine methods. Hydraulic seeding equipment and accessories shall conform to the equipment and accessories described in subsection 212.04(c). Seeded areas damaged due to circumstances beyond the Contractor's control shall be repaired and reseeded as ordered. Payment for this corrective work, when ordered, shall be at the contract prices. Multiple seeding operations shall be anticipated as portions of job are completed to take advantage of growing conditions and to comply with Section 208 and subsection 212.03. METHOD OF MEASUREMENT
212.07 The quantities of lawn seeding and native seeding will not be measured but shall be the
quantities designated in the Contract, except that measurements will be made for revisions requested by the Engineer, or for discrepancies of plus or minus five percent of the total quantity designated in the Contract. The quantity of lawn seeding shall include soil preparation, water, fertilizer , and seed, completed, and accepted. The quantity of native seeding shall include soil preparation, fertilizer, soil conditio ner, and seed applied, completed, and accepted. The quantity of sod to be measured will be the actual number of square feet, including soil preparation, water, fertilizer , and sod, completed, and accepted. When soil conditioner is measured and paid for separately, it will be measured by the actual number of acres where soil conditioner is applied and will be paid for as Soil Conditioning. The Contractor shall furnish the Engineer with seed certifications and analysis, fertilizer analysis, and bag weight tickers before placing any seed or fertilizer. Any seed or fertilizer placed by the Contractor without the Engineer’s approval will not be paid for. Measurement for acres will be by slope distances. 212.08 212-8 BASIS OF PAYMENT
212.08 The accepted quantities of lawn seeding, native seeding, soil conditioning, and sod
will be paid for at the contract unit price for each of the pay items listed below that appear in the bid schedule. Payment will be made under: Pay Item Pay Unit Seeding (Lawn) Acre Seeding (Native) Acre Sod Square Foot Soil Conditioning Acre Soil preparation, water, seed, fertilizer, and soil conditioner, incorporated into the seeding sodding or soil conditioning will not be paid for separately but shall be included in the work. Adjusting or readjusting seeding or fertilizing equipment will not be paid for separately but shall be included in the work. 213.01 213-1 SECTION 213 MULCHING DESCRIPTION
213.01 This work consists of mulching the seeded areas, furnishing and placing wood chip
mulch in the planting beds and plant saucers, furnishing and applying hydromulch with tackifier on roadway ditches and slopes, furnishing and placing tackifier on mulch or soil on roadway ditches or slopes, an d furnishing and installing metal landscape border for the separation of planting beds, per the Contract or as directed. Mulching may be accomplished by the crimping method using straw or hay, by the hydraulic method using wood cellulose fiber mulch, or by other approved methods with approved materials. When a specific mulching method is required, it will be designated in the Contract. This work includes furnishing and applying spray -on mulch blanket or bonded fiber matrix on top of rock cuts and slopes after seeding or as temporary stabilization as shown on the plans or as directed by the Engineer. MATERIALS
213.02 Materials shall conform to the following requirements.
a.Mulching . Materials for mulching shall consist of Certified Weed Free field or marsh hay or straw of oats, barley, wheat, rye, or triticale certified under the Colorado Department of Agriculture Weed Free Forage Certification Program and inspected as regulated by the Weed Free Forage Act, Title 35, Article 27.5, CRS. Each certified weed free mulch bale shall be identified by one of the following:
1.One of the ties binding the bale shall consist of blue and orange twine, or
2.The bale shall have a regional Forage Certification Program tag indicating the Regional Forage Certification Program Number. Mulch shall be inspected for and Regionally Certified as weed free based on the Regionally Designated Noxious Weed and Undesirable Plant List for Colorado, Wyoming, Montana, Nebraska, Utah, Idaho, Kansas, and South Dakota. The Contractor shall not unload certified weed free mulch bales or remove their identifying twine, wire, or tags until the Engineer has inspected and accepted them. The Contracto r shall provide a transit certificate that has been filled out and signed by the grower and by the Department of Agriculture inspector. The Contractor may obtain a current list of Colorado Weed Free Forage Crop Producers who have completed certification by contacting the Colorado Department of Agriculture, Division of Plant Industry. Straw or hay in a stage of decomposition (discolored, brittle, rotten, or moldy) or old, dry mulch that breaks in the crimping process will not be accepted. The type and application rate of mulch material shall be as designated in the Contract.
Source: Colorado Standard Specifications for Road and Bridge Construction, 2023 Edition. Pages 271–278 of 943.