Soils are critical to the success of the planting and turf areas around the greenway.
While protection of existing topsoil is paramount during construction, soils will likely require preparation and remediation prior to the placement of plant material.
- Soil preparation should occur in all areas to be planted, including areas to be seeded with turfgrass.
- Turf, native seed, and planting areas will differ slightly in their requirements for soil preparation.
- Soils should be tested prior to amendment. Amendments should be based on soils laboratory test results and the plant material to be used.
- As a baseline minimum, areas should have existing, invasive plants removed prior to soil placement or preparation.
- Imported soils or soil amendments should be tilled into to the depths indicated below
- Imported topsoil should be of a soil texture/composition similar to that of the native soil in the area, typically a clay loam naturally formed soil from off-site sources.
- If organic matter is required, limit organic matter to 3% or less.
- pH range should be between 5.5 – 7.5.
- Ensure soil is free of extraneous material harmful to plant growth as well as large materials such as stone, clods, roots, clay lumps, and pockets of course sand exceeding 2” in any dimension.
- Do not apply planting soil or till if existing soil or subgrade is frozen, muddy, or excessively wet.
- When placing and mixing planting soil over exposed subgrade, apply and mix unamended soil and amendments in lifts not exceeding 8” in loose depth for material compacted by compaction equipment, and not more than 4” in loose depth for material compacted by hand operated tampers. Compact each blended lift of planting soil to 75 – 82 percent of maximum Standard Proctor density according to ASTM D 698 and tested in place.
- Grade planting soil to a smooth, uniform surface plane with loose, uniformly fine texture. Roll and rake, remove ridges, and fill depressions to meet finish grades.
IMPORTED TOPSOIL PREPARATION
EXISTING TOPSOIL PREPARATION