Specifying Soils for Complex Landscapes presentation outline Pine&Swallow ENVIRONMENTAL Soil Design Strategies Natural vs Blended Simple vs Complex Specifying Blended Soils components mix ratios vs use specification controls Teardrop Park horticultural strategy specifications Robert Pine, PE, MLA, ASLA
Blended Soils Specifying Soils for Complex Landscapes Natural Pine&Swallow Loam Dealer Limited Resource Mix of whatever came in that day Controlled performance, Sustainable Soil Design Strategies Natural vs Blended
Simple vs Complex Landscapes Specifying Soils for Complex Landscapes Pine&Swallow Soil Design Strategies Natural vs Blended TanglewoodTeardrop Park
Base Loam Blended Soil Compost Sand Specifying Soils for Complex Landscapes Pine&Swallow Specifying Blended Soils Components
Specifying Soils for Complex Landscapes Pine&Swallow Specifying Blended Soils Components Provides silt and clay particles stable organics cation exchange capacity natural soil biology As percentage in a blend increases nutrient and water holding capacities infiltration rate and aeration resistance to compaction Note: Good quality topsoil is required for appropriate gradation, organics and soil biology. Natural Topsoil
Specifying Soils for Complex Landscapes Pine&Swallow Specifying Blended Soils Components Provides structure macropore space As percentage in a blend increases aeration infiltration rate resistance to compaction water holding capacity nutrient holding capacity Note: Well graded sand reduces aeration, infiltration and resistance to compaction! Uniform Coarse Sand
Specifying Soils for Complex Landscapes Pine&Swallow Specifying Blended Soils Components Provides organic content micro-organisms As percentage in a blend increases water holding capacity soil biology resistance to compaction resistance to anaerobic conditions Note: Immature compost creates bad soil biology and increased vulnerability to anaerobic conditions. Mature Compost
Specifying Soils for Complex Landscapes Pine&Swallow Estimated Mix Ratio for each soil Grain Size Distribution Coefficient of Uniformity Organic Content Horticultural Requirements (CEC, pH, nutrients, etc.) Compaction Range Saturated Hydraulic Conductivity at maximum compaction Primary Mix Design Specifications Purpose define the soil blend control soil properties Specifying Blended Soils Specification Controls
Specifying Soils for Complex Landscapes Pine&Swallow Specifying Blended Soils Specification Controls Testing and confirmation of base materials: sand, loam, compost Testing to confirm mix ratios Batch production and testing prior to delivery for quality control Handling and Placement procedures Control of wet soils Primary Process Specifications Ensure quality control Protect soil quality Purpose
Teardrop Park Horticultural Strategy Specifying Soils for Complex Landscapes Pine&Swallow
Specifying Soils for Complex Landscapes Pine&Swallow Teardrop Park Specifications Soil Requirements Withstand heavy use High infiltration rate High Use Turf Specifications Mix Ratio *3S : 1.5L : 1C % passing 270 sieve11 -14% Uniformity ratio D 70 /D 20 < 4.5 Organic content4 - 5% Compaction % Hydraulic conductivity> 4 inches/hr * S = Sand L = Base Loam C = Compost
Specifying Soils for Complex Landscapes Pine&Swallow Teardrop Park Specifications Soil Requirements Withstand moderate use Moderate infiltration rate Reduced water requirements Passive Use Lawn (not used at Teardrop Park) Specifications Mix Ratio *2S : 1.5L : 1C % passing 270 sieve % Uniformity ratio D 70 /D 20 < 5.0 Organic content4 - 6% Compaction % Hydraulic conductivity> 3 inches/hr * S = Sand L = Base Loam C = Compost
Specifying Soils for Complex Landscapes Pine&Swallow Teardrop Park Specifications Soil Requirements: rooting zone for trees / shrubs free draining not vulnerable to anaerobics Horticultural Subsoil Specifications Mix Ratio *2S : 1L % passing 270 sieve % Uniformity ratio D 70 /D 20 < 6.0 Organic content2 - 3% Compaction % Hydraulic conductivity> 2 inches/hr * S = Sand L = Base Loam C = Compost
Specifying Soils for Complex Landscapes Pine&Swallow Teardrop Park Specifications Soil Requirements: recreate natural forest soil profile encouraging shallow feeder roots deep rooting in horticultural subsoil Trees with understory no ground cover Specifications Mix Ratio *2S : 1L : 3C % passing 270 sieve % Uniformity ratio D 70 /D 20 < 6.0 Organic content9 - 11% Compaction % Hydraulic conductivity> 3 inches/hr * S = Sand L = Base Loam C = Compost
Specifying Soils for Complex Landscapes Pine&Swallow Teardrop Park Specifications Soil Requirements: recreate natural forest soil profile suitable for ground cover plants Trees with understory with ground cover Specifications Mix Ratio *2S : 1L : 2C % passing 270 sieve % Uniformity ratio D 70 /D 20 < 6.0 Organic content6 - 9% Compaction % Hydraulic conductivity> 3 inches/hr * S = Sand L = Base Loam C = Compost
Specifying Soils for Complex Landscapes Pine&Swallow Teardrop Park Specifications Soil Requirements: saturated conditions support wetland plantings high water holding capacity Marsh Planting Soil Specifications Mix Ratio *1S : 2C % passing 270 sieve8 - 12% Uniformity ratio D 70 /D 20 < 4.5 Organic content % Compaction % Hydraulic conductivity> 4 inches/hr Note: Medium Sand not Coarse * S = Sand L = Base Loam C = Compost
Specifying Soils for Complex Landscapes Pine&Swallow Teardrop Park Specifications Soil Requirements: structural support for heavy boulders horticultural support for plantings Boulder Base Mix Specifications Mix Ratio: 1 part 1.5 to 2 inch crushed stone 1 part tree soil mix Placed beneath heavy boulders and compacted thoroughly
Specifying Soils for Complex Landscapes Pine&Swallow Teardrop Park Specifications Soil Requirements: provide long term stability protection from erosion tree horticultural support Steep slopes Specifications Mix Ratio: 2 to 4 oz fibers per cubic foot thoroughly mixed with planting soil Placed and compacted to normal compaction range for specified planting medium
Specifying Soils for Complex Landscapes Pine&Swallow Teardrop Park Specifications Soil Requirements: provide tree rooting volume provide support for pavement prevent settlements Trees in paved areas Specifications Mix Ratio *4S : 1L : 1C % passing 270 sieve7 - 9% Uniformity ratio D 70 /D 20 < 3 Organic content2 - 3% Compaction % Hydraulic conductivity> 6 inches/hr * S = Sand L = Base Loam C = Compost
Specifying Soils for Complex Landscapes recap Pine&Swallow ENVIRONMENTAL Soil Design Strategies Natural vs Blended Simple vs Complex Specifying Blended Soils components mix ratios vs use specification controls Teardrop Park horticultural strategy specifications Robert Pine, PE, ASLA