Topsoil Design Guidelines
Prior to topsoil application, the contractor scarify the soil areas where topsoil is to be applied to a depth of one foot (1′) and remove and haul off all construction debris before spreading the topsoil. No scarification or subsoiling should be done within the dripline of any existing tree. The first 4” of topsoil needs to be mixed into the scarified top layer of existing soil. Continue adding soil in 4” lifts until finish grade is established.
A minimum of four inches (4”) of topsoil is to be applied in all disturbed areas. A minimum of twelve inches (12”) of topsoil is to be applied in all landscape plant bed areas. Exceptional care should be taken when spreading topsoil around trees. Soil around existing trees should not exceed the grade which existed prior to construction. Grade lawn areas and beds to conform to finish grades and profiles indicated on drawings, assuring uninterrupted drainage pattern, free of hollows and pockets. In areas where subgrade is poorly drained, provide corrective drainage indicated on drawings. If these measures do not correct drainage notify Architect for his direction prior to further work.
- 3 parts sandy-loam topsoil with additive required to bring pH to 5.5-6.5 range.
- 1 part composted pine bark organic material
After the soils have been ripped, and before the required topsoil is spread, and final grades approved, clear the site of all surface trash and other objects that will hinder the installation and maintenance of the planted areas. The clean up includes plant bed areas, lawn areas, rights-of-way adjacent to the site, buffer areas, and lay down areas.
Surface Drainage of Planted Areas
The Contractor shall bear final responsibility for proper surface drainage of all areas within the project
Stabilization (grassing) of Disturbed Areas
Repair and seed all areas that are disturbed during construction. Till disturbed area to a depth of 6 inches. Incorporate 18-24-12 fertilizer at a rate of 10 lb. per 1000 square feet. Evenly distribute Turf Type fescue blend grass and perennial rye seed at a rate of 10 lb. per 1000 square feet. Lightly rake seeded areas, mulch with 1″ clean wheat straw, and water thoroughly. Areas that will be converted to plant beds can be stabilized using pine straw or organic mulch.