Seeding, Permanent
Definition
The establishment of perennial vegetative cover on disturbed areas.
Purpose
- Permanent seeding of grass provides stabilization to the soil by holding soil particles in place.
- Vegetation reduces sediments and runoff to downstream areas by slowing the velocity of runoff and permitting greater infiltration of the runoff.
- Vegetation also filters sediments, helps the soil absorb water, improves wildlife habitats, and enhances the aesthetics of a site.
Advantages
- Advantages of seeding over other means of establishing plants include the small initial establishment cost, the wide variety of grasses and legumes available, low labor requirement, and ease of establishment in difficult areas.
- Seeding is usually the most economical way to stabilize large areas.
- Well established grass and ground covers can give an aesthetically pleasing, finished look to a development.
- Once established, the vegetation will serve to prevent erosion and retard the velocity of runoff.
Disadvantages/Problems
- Disadvantages which must be dealt with are the potential for erosion during the establishment stage, a need to reseed areas that fail to establish, limited periods during the year suitable for seeding, and a need for water and appropriate climatic conditions during germination. Vegetation and mulch cannot prevent soil slippage and erosion if soil is not inherently stable.
- Coarse, high grasses that are not mowed can create a fire hazard in some locales. Very short mowed grass, however, provides less stability and sediment filtering capacity.
- Grass planted to the edge of a watercourse may encourage fertilizing and mowing near the water’s edge and increase nutrient and pesticide contamination.
- Depends initially on climate and weather for success.
- May require regular irrigation to establish and maintain.
Planning Considerations
- Selection of the right plant materials for the site, good seedbed preparation, timing, and conscientious maintenance are important. Whenever possible, native species of plants should be used for landscaping. These plants are already adapted to the locale and survivability should be higher than with "introduced" species.
- Native species are also less likely to require irrigation, which can be a large maintenance burden and is neither cost-effective nor ecologically sound.
- If non-native plant species are used, they should be tolerant of a large range of growing conditions, as low-maintenance as possible, and not invasive.
- Consider the microclimate within the development area. Low areas may be frost pockets and require hardier vegetation since cold air tends to sink and flow towards low spots. South-facing slopes may be more difficult to re-vegetate because they tend to be sunnier and drier.
- Divert as much surface water as possible from the area to be planted.
- Remove seepage water that would continue to have adverse effects on soil stability or the protecting vegetation. Subsurface drainage or other engineering practices may be needed. In this situation, a permit may be needed from the local Conservation Commission: check ahead of time to avoid construction delays.
- Provide protection from equipment, trampling and other destructive agents.
- Vegetation cannot be expected to supply an erosion control cover and prevent
- slippage on a soil that is not stable due to its texture, structure, water movement, or excessive slope.
Seeding Grasses and Legumes
Install needed surface runoff control measures such as gradient terraces, berms, dikes, level spreaders, waterways, and sediment basins prior to seeding or planting.
Seedbed Preparation
If infertile or coarse-textured subsoil will be exposed during land shaping, it is best to stock-pile topsoil and respread it over the finished slope at a minimum 2-to 6-inch depth and roll it to provide a firm seedbed. If construction fill operations have left soil exposed with a loose, rough, or irregular surface, smooth with blade and roll. Loosen the soil to a depth of 3-5 inches with suitable agricultural or construction equipment. Areas not to receive top soil shall be treated to firm the seedbed after incorporation of the lime and fertilizer so that it is depressed no more than 1/2 -1 inch when stepped on with a shoe. Areas to receive topsoil shall not be firmed until after topsoiling and lime and fertilizer is applied and incorporated, at which time it shall be treated to firm the seedbed as described above. This can be done by rolling or cultipacking.
Cool Season Grasses
Cool Season Grasses grow rapidly in the cool weather of spring and fall, and set seed in June and July. Cool season grasses become dormant when summer temperatures persist above 85 degrees and moisture is scarce.
Lime and Fertilizer
Apply lime and fertilizer according to soil test. In absence of a soil test, apply lime (a pH of 5.5 -6.0 is desired) at a rate of 2.5 tons per acre and 10-20-20 analysis fertilizer at a rate of 500 pounds per acre (40 %of N to be in an organic or slow release form). Incorporate lime and fertilizer into the top 2-3 inches of soil.
Seeding Dates
Seeding operations should be performed within one of the following periods:
- April 1 -May 31
- August 1 -September 10
Seeding Methods
Seeding should be performed by one of the following methods. Seed should be planted to a depth of 1/4 to 1/2 inches.
- Drill seedings,
- Broadcast and rolled, cultipacked or tracked with a small track piece of construction equipment,
- Hydroseeding, with subsequent tracking.
Mulch
Mulch the seedings with straw applied at the rate of 1/2 tons per acre. Anchor the mulch with erosion control netting or fabric on sloping areas.
Warm Season Grasses
Warm Season Grasses begin growth slowly in the spring, grow rapidly in the hot summer months and set seed in the fall. Many warm season grasses are sensitive to frost in the fall, and the top growth may die back. Growth begins from the plant base the following spring.
Lime and Fertilizer
Lime to attain a pH of at least 5.5.Apply a 0-10-10 analysis fertilizer at the rate of 600 lbs. /acre.
Incorporate both into the top 2-3 inches of soil. (30 lbs. Of slow release nitrogen should be applied after emergence of grass in the late spring.)
Seeding Dates
Seeding operations should be performed as an early spring seeding (April 1-May 15) with the use of cold treated seed.
Seeding Methods
Seeding should be performed by one of the following methods:
- Drill seedings (de-awned or de-bearded seed should be used unless the drill is equipped with special features to accept awned seed).
- Broadcast seeding with subsequent rolling, cultipacking or tracking the seeding with small track construction equipment. Tracking should be oriented up and down the slope.
- Hydroseeding with subsequent tracking. If wood fiber mulch is used, it should be applied as a separate operation after seeding and tracking to assure good seed to soil contact.
Mulch
Mulch the seedings with straw applied at the rate of 1/2 tons per acre. Anchor the mulch with erosion control netting or fabric on sloping areas.
Seed Mixtures for Permanent Cover
Recommended mixtures for permanent seeding are provided on the following pages. Select plant species which are suited to the site conditions and planned use. Soil moisture conditions, often the major limiting site factor, are usually classified as follows:
- Dry - Sands and gravels to sandy loams. No effective moisture supply from seepage or a high water table.
- Moist - Well drained to moderately well drained sandy loams, loams, and finer; or coarser textured material with moderate influence on root zone from seepage or a high water table.
- Wet - All textures with a water table at or very near the soil surface, or with enduring seepage. When other factors strongly influence site conditions, the plants selected must also be tolerant of these conditions.
| Permanent Seeding Mixtures |
| Seed, Pounds per: |
| Mix | Site | Seed Mixture | Acre | 1,000 sf | Remarks |
| 1 | Dry | Little Bluestem or Broomsedge | 10 | 0.25 | Use Warm Season planting procedure.
Roadsides |
| | Tumble Lovegrass* | 1 | 0.10 | Sand and Gravel Stabilization |
| | Switchgrass | 10 | 0.25 | Clover requires Inoculation with nitrogen-fixing bacteria |
| | Bush Clover* | 2 | 0.10 | |
| | Red Top | 1 | 0.10 | Rates for this mix are for PLS. |
| 2 | Dry | Deertongue | 15 | 0.35 | Use Warm Season planting procedures. |
| | Broomsedge | 10 | 0.25 | Acid sites/Mine spoil |
| | Bush Clover* | 2 | 0.10 | Clover requires Inoculation with nitrogen-fixing bacteria |
| | Red Top | 1 | 0.10 | Rates for this mix are for PLS. |
| 3 | Dry | Big Bluestem | 10 | 0.25 | Use Warm Season planting procedures. |
| | Indian Grass | 10 | 0.25 | Eastern Prairie appearance |
| | Switchgrass | 10 | 0.25 | Sand and Gravel pits. |
| | Little Bluestem | 10 | 0.25 | Golf Course Wild Area |
| | Red Top or | 1 | 0.10 | Sanitary Landfill Cover seeding |
| | Perennial Ryegrass | 10 | 0.25 | Wildlife Areas |
| | | | | OK to substitute Poverty Dropseed in place of Red Top/Ryegrass. |
| | | | | Rates for this mix are for PLS. |
| 4 | Dry | Flat Pea | 25 | 0.60 | Use Cool Season planting procedures |
| | Red Top | 2 | 0.10 | Utility Right-of-Ways (tends to suppress woody growth) |
| | Perennial Ryegrass | 15 | 0.35 | |
| 5 | Dry | Little Bluestem | 5 | 0.10 | Use Warm Season planting procedures. |
| | Switchgrass | 10 | 0.25 | Coastal sites |
| | Beach Pea* | 20 | 0.45 | Rates for or Bluestem and Switchgrass are for PLS |
| | Perennial Ryegrass | 10 | 0.25 | |
| 6 | Dry-Moist | Red Fescue | 10 | 0.25 | Use Cool Season planting procedure. |
| | Canada Bluegrass | 10 | 0.25 | Provides quick cover but is non-aggressive; will tend to allow Indigenous plant colonization. |
| | Perennial Ryegrass | 10 | 0.25 | General erosion control on variety of sites, including forest roads. skid trails and landings. |
| | Red Top | 1 | 0.10 | |
| 7 | Dry-Moist | Switchgrass | 10 | 0.25 | Use Warm Season planting procedure. |
| | Virginia Wild Rye | 5 | 0.10 | Coastal plain / flood plain |
| | Big Bluestem | 15 | 0.35 | Rates for Bluestem and Switchgrass are for PLS |
| | Red Top | 1 | 0.10 | |
| 8 | Moist Wet | Creeping Bentgrass | 5 | 0.10 | Use Cool Season planting procedure. |
| | Fringed Bromegrass | 5 | 0.10 | Pond Banks |
| | Fowl Meadowgrass | 5 | 0.10 | Waterways/ditch banks |
| | Bluejoint Reedgrass or Rice Cutgrass | 2 | 0.10 | |
| | Perennial Ryegrass | 10 | 0.25 | |
| 9 | Moist Wet | Red Fescue | 5 | 0.10 | Salt Tolerant |
| | Creeping Bentgrass | 2 | 0.10 | Fescue and Bentgrass provide low growing appearance, while Switchgrass provides tall cover for wildlife. |
| | Switchgrass | 8 | 0.20 | |
| | Perennial Ryegrass | 10 | 0.25 | |
| 10 | Moist Wet | Red Fescue | 5 | 0.10 | Use Cool Season planting procedure. |
| | Creeping Bentgrass | 5 | 0.10 | Trefoil requires inoculation with nitrogen fixing bacteria. |
| | Virginia Wild Rye | 8 | 0.20 | |
| | Wood Reed Grass* | 1 | 0.10 | Suitable for forest access roads, skid trails and other partial shade situations. |
| | Showy Tick Trefoil* | 1 | 0.10 | |
| 11 | Moist Wet | Creeping Bentgrass | 5 | 0.10 | Use Cool Season planting procedure. |
| | Bluejoint Reedgrass | 1 | 0.10 | Suitable for waterways, pond or ditch banks. |
| | Virginia Wild Rye | 3 | 0.10 | Trefoil requires inoculation with nitrogen fixing bacteria. |
| | Fowl Meadowgrass | 10 | 0.25 | |
| | Showy Tick Trefoil* | 1 | 0.10 | |
| | Red Top | 1 | 0.10 | |
| 12 | Wet | Bluejoint Reedgrass | 1 | 0.10 | Use Cool Season planting procedure. |
| | Canada Manna Grass | 1 | 0.10 | OK to seed in saturated soil conditios, but not in standing water. |
| | Rice Cut Grass | 1 | 0.10 | |
| | Creeping Bent Grass | 5 | 0.10 | Suitable as stabilization seeding for created wetland. |
| | Fowl Meadow Grass | 5 | 0.10 | All species in this mix are native to Massachusetts. |
| 13 | Dry-Moist | American Beachgrass | 18" centers | 18" centers | Vegetative planting with dormant culms, 3-5 culms per planting |
| 14 | Inter-Tidal | Smooth Cordgrass | 12-18" | 12-18" | Vegetative planting with transplants |
| | Saltmeadow Cordgrass | centers | centers | |
Notes
* Species such as Tumble Lovegrass, Fringed Bromegrass, Wood Reedgrass, Bush Clover and Beach Pea, while known to be commercially available from specific seed suppliers, may not always be available from your particular seed suppliers. The local Natural Resources Conservation Service office may be able to help with a source of supply. In the event a particular species listed in a mix can not be obtained, however, it may be possible to substitute another species.
Seed mixtures by courtesy of Natural Resources Conservation Service, Amherst, MA.
(PLS) Pure Live Seed
Warm Season grass seed is sold and planted on the basis of pure live seed. An adjustment is made to the bulk rate of the seed to compensate for inert material and non-viable seed. Percent of pure live seed is calculated by multiplying the percent purity by the percent germination;
(%purity)x (%germination)=percent PLS.
For example, if the seeding rate calls for 10 lbs. /acre PLS and the seed lot has a purity of 70%and germination of 75%,the PLS factor is:
(.70 x .75)=.53
10 lbs. divided by .53 =approx.19 lbs.
Therefore, 19 lbs. of seed from the particular lot will need to be applied to obtain 10 lbs. of pure live seed.
Special Note
Tall Fescue, Reed Canary Grass, Crownvetch and Birdsfoot Trefoil are no longer recommended for general erosion control use in Massachusetts due to the invasive characteristics of each. If these species are used, it is recommended that the ecosystem of the site be analyzed for the effects species invasiveness may impose. The mixes listed in the above mixtures include either species native to Massachusetts or non-native species that are not perceived to be invasive, as per the Massachusetts Native Plant Advisory Committee.
Wetlands Seed Mixtures
For newly created wetlands, a wetlands specialist should design plantings to provide the best chance of success. Do not use introduced, invasive plants like reed canarygrass (Phalaris arundinacea) or purple loosestrife (Lythrum salicaria). Using plants such as these will cause many more problems than they will solve.
The following grasses all thrive in wetland situations:
- Fresh Water Cordgrass (Spartina pectinata)
- Marsh/Creeping Bentgrass (Agrostis stolonifera,var.Palustric)
- Broomsedge (Andropogon virginicus)
- Fringed Bromegrass (Bromus ciliatus)
- Blue Joint Reed Grass (Calamagrostis cavedensis)
- Fowl Meadow Grass (Glyceria striata)
- Riverbank Wild Rye (Elymus riparius)
- Rice Cutgrass (Leersia or yzoides)
- Stout Wood Reed (Cinna arundinacea)
- Canada Manna Grass (Glyceria canadensis)
A sample wetlands seed mix developed by The New England Environmental Wetland Plant Nursery is shown on the following page.
Wetland Seed Mixture
The New England Environmental Wetland Plant Nursery has developed a seed mixture which is specifically designed to be used in wetland replication projects and stormwater detention basins. It is composed of seeds from a variety of indigenous wetland species. Establishing a native wetland plant understory in these areas provides quick erosion control, wildlife food and cover, and helps to reduce the establishment of undesirable invasive species such as Phragmites and purple loosestrife (Lythrum salicaria).The species have been selected to represent varying degrees of drought tolerance, and will establish themselves based upon microtopography and the resulting variation in soil moisture.
Common Name
(Scientific Name) | % in Mix | Comments |
Lurid Sedge
(Carex lurida) | 30 | A low ground cover that tolerates mesic sites in addition to saturated areasl prolific seeder in second growing season. |
Fowl Meadow Grass
(Glyceria Canadensis) | 25 | Prolific seed producer that is a valuable wildlife food source. |
Fringed Sedge
(Carex crinita) | 10 | A medium to large sedge that tolerates saturated areas; good seed producer. |
Joe-Pye Weed
(Eupatoriadelphus maculatus) | 10 | Flowering plant that is valuable for wildlife cover. Grows to 4 feet. |
Brook Sedge
(Carex spp., Ovales group) | 10 | Tolerates a wide range of hydrologic conditions. |
Woolgrass
(Scirpus cyperinus) | 5 | Tolerates fluctuating hydrology |
Boneset
(Eupatorium perforliatum) | 5 | Flowering Plant that is valuable for wildlife cover. Grows to 3 feet. |
Tussock Sedge
(Carex stricta) | <5 | Grows in elevated hummocks on wet sites, may grow rhizomonously on drier sites. |
Blue Vervain
(Verbena hastata) | <5 | A native plant that bears attractive, blue flowers. |
| The recommended application rate is one pound per 5,000 square feet when used as an understory cover. This rate should be increased to one pound per 2,500 square feet for detention basins and other sites which require a very dense cover. For best results, a late fall application is recommended. This mix is not recommended for standing water |
Maintenance
- Inspect seeded areas for failure and make necessary repairs and reseed immediately. Conduct or follow-up survey after one year and replace failed plants where necessary.
- If vegetative cover is inadequate to prevent rill erosion, overseed and fertilize in accordance with soil test results.
- If a stand has less than 40% cover, reevaluate choice of plant materials and quantities of lime and fertilizer. Re-establish the stand following seedbed preparation and seeding recommendations, omitting lime and fertilizer in the absence of soil test results. If the season prevents resowing, mulch or jute netting is an effective temporary cover.
- Seeded areas should be fertilized during the second growing season. Lime and fertilize thereafter at periodic intervals, as needed.
References
North Carolina Department of Environment, Health, and Natural Resources, Erosion and Sediment Control Field Manual , Raleigh, NC, February 1991.
Personal communication, Richard J. DeVergilio, USDA, Natural Resources Conservation Service, Amherst, MA. U.S. Environmental Protection Agency, Storm Water Management For Construction Activities, EPA-832-R-92-005, Washington, DC, September,1992.
Washington State Department of Ecology, Stormwater Management Manual for the Puget Sound Basin , Olympia, WA, February,1992.