1 Scope
NOTE This standard governs the furnishing and installation of landscape plant material and the preparation of the soil in which it is planted. (1.1)
NOTE The work under this standard covers both the planting soil and the plant material it supports: (1.2)
- Soil preparation covers stripping, stockpiling, importing, testing, amending, placing, and finish grading of planting soil and the preparation of the subgrade beneath it.
- Plant material covers trees, shrubs, ground covers, vines, perennials, and turf established by sod or seed, including their handling, setting, backfilling, mulching, support, and establishment.
NOTE The work shall include all soil amendments, mulch, support hardware, and incidental materials required to complete the planting and to maintain it through the establishment period. (1.3)
NOTE This standard must be coordinated with the adjacent site work so that planting soil depth, underdrains, and bed drainage are not in conflict. Subgrade preparation, drainage, and finish grade in planting areas shall be reconciled with the site earthwork and storm drainage work, and soil preparation depths, subgrade scarification, and imported fill quality shall be reconciled with the earthwork so that planting soil is not placed over uncompacted or over-compacted subgrade. Permanent irrigation supplying the planting is specified separately; coordinate establishment watering with the irrigation work and resolve responsibility for water supply before the establishment period begins. (1.4)
1.5 Referenced Standards
NOTE The following standards are referenced in this document; the edition in effect at the time the plant material is purchased shall govern unless a specific edition is named. (1.6)
| Standard |
Title |
| ANSI Z60.2 |
American Standard for Nursery Stock |
| ANSI A300 |
Tree Care Standards |
| ISA Best Management Practices |
Planting (non-mandatory guidance accompanying ANSI A300) |
| ASTM D5268 |
Standard Specification for Topsoil Used for Landscaping and Construction Purposes |
| ASTM D5975 |
Standard Test Method for Determining the Stability of Compost by Measuring Oxygen Consumption |
| ASTM D1556 |
Standard Test Method for Density and Unit Weight of Soil In Place by the Sand-Cone Method |
| ASTM D4318 |
Standard Test Methods for Liquid Limit, Plastic Limit, and Plasticity Index of Soils |
| ASTM D7928 |
Standard Test Method for Particle-Size Distribution of Fine-Grained Soils by the Sedimentation (Hydrometer) Analysis |
| AASHTO M 147 |
Standard Specification for Materials for Aggregate and Soil-Aggregate Subbase, Base, and Surface Courses |
| USCC STA |
Seal of Testing Assurance Program (compost tested to TMECC protocols) |
2 Definitions
NOTE The following terms are used throughout this standard: (2.1)
- Root flare is the zone at the base of the trunk where the trunk widens into the structural roots; its top sets the reference for planting depth and for caliper measurement.
- Caliper is the diameter of the trunk measured at a defined height above the root flare and is the primary size class for shade and ornamental trees.
- Balled-and-burlapped (B&B) stock is nursery stock dug with an intact ball of native soil wrapped in burlap and, for larger sizes, supported by a wire basket.
- Container stock is nursery stock grown in a rigid container of a defined class; container class, not gallon volume alone, sets the minimum acceptable size under ANSI Z60.2.
- Bare-root stock is dormant deciduous stock dug without soil on the roots and is acceptable only during the dormant planting season.
- In-ground fabric bag stock is grown in a permeable fabric bag set in the field that air-prunes roots and is harvested with the bag.
- Establishment period is the defined interval after planting during which the plant is watered, monitored, and maintained until it is judged self-supporting.
- Planting soil is the topsoil or engineered blend, tested and amended as required, that is placed in planting beds, tree pits, and turf areas to support root growth.
- Subgrade is the prepared native soil surface beneath the planting soil; its compaction and drainage govern how the planting soil performs.
3 Submittals
3.1 Action Submittals
3.1.1The Contractor shall submit the following action submittals for review before delivery of the corresponding material:
- Plant material list keyed to the planting plan, identifying each species by botanical and common name, size class, caliper or height, root form, and quantity.
- Source nursery certifications stating the ANSI Z60.2 edition to which stock is graded and confirming freedom from quarantine pests.
- Topsoil and planting soil test reports per ASTM D5268, ASTM D7928, ASTM D4318, with pH, organic matter, soluble salts, and gradation.
- Compost maturity report per ASTM D5975 and, where required, USCC STA certification with TMECC results.
- Manufacturer or supplier data for mulch, staking hardware, anti-desiccant, and soil amendments.
- Soil amendment plan stating lime, sulfur, fertilizer, and compost rates derived from the soil test results.
- Samples of mulch, burlap, and staking tie material as requested by the reviewer.
☑ Plant material list keyed to plan
☑ Nursery certification with ANSI Z60.2 edition
☑ Topsoil / planting soil test report (ASTM D5268)
☑ Compost maturity report (ASTM D5975)
☑ Mulch, staking, and amendment product data
☑ Soil amendment plan with rates
☐ Material samples
NOTE Plant material substitutions shall not be made without the reviewer's written approval, and any approved substitution shall meet the size class and form of the originally specified material. (3.1.2)
3.2.1The Contractor shall submit the following informational submittals before starting the corresponding work:
- Accredited laboratory qualifications for soil and compost testing.
- Planting and soil installation schedule keyed to the planting seasons.
- Establishment-period maintenance plan stating watering frequency, volume, and responsibility.
- Source of imported topsoil with sampling location and chain of custody.
☑ Testing laboratory qualifications
☑ Planting and soil installation schedule
☑ Establishment maintenance plan
☑ Imported topsoil source documentation
3.3 Closeout Submittals
3.3.1The Contractor shall submit the following closeout submittals before final acceptance:
- Record drawings of as-planted locations where field-adjusted from the planting plan.
- Final soil test reports for installed planting soil.
- Maintenance and watering instructions for the owner covering the warranty period.
- Warranty documentation stating start date, duration, and replacement terms.
☑ As-planted record drawings
☐ Final installed soil test reports
☑ Owner maintenance and watering instructions
☑ Warranty documentation
4 Quality Assurance
NOTE Soil and compost testing shall be performed by a laboratory accredited for the referenced test methods, and test reports shall name the laboratory and the methods used. (4.1)
4.1.1Soil testing shall be performed by a laboratory accredited under an A2LA or equivalent program for the soil test methods specified.
4.1.2Soil sampling for acceptance testing shall be taken from the material as stockpiled or as delivered, not from the source bank, so that the tested material represents what will be placed.
4.1.3Imported topsoil shall be tested and approved before any of it is placed in planting areas.
NOTE Source quality of plant material shall be verified before delivery so that defective or undersized stock is rejected at the nursery rather than after installation. (4.2)
4.2.1Plant material shall be nursery-grown stock that has been transplanted or root-pruned within the period required by ANSI Z60.2 for its size class.
4.2.2The reviewer may inspect and tag plant material at the source nursery before digging, and tagged material shall not be substituted without approval.
4.2.3Plant material shall be true to the botanical name specified, and mislabeled stock shall be rejected.
NOTE Pre-installation conditions in planting areas shall be verified so that planting does not proceed over unsuitable subgrade or out of season. (4.3)
4.3.1The Contractor shall verify finish subgrade elevation and drainage in each planting area before placing planting soil, and shall report conditions that prevent compliant work.
4.3.2Planting shall be performed only within the planting season appropriate to the plant type and climate, except where the reviewer authorizes off-season planting with supplemental measures.
☑ Topsoil acceptance (ASTM D5268)
☑ Particle-size / gradation (ASTM D7928)
☐ Atterberg limits (ASTM D4318)
☐ In-place density (ASTM D1556)
☐ Compost stability (ASTM D5975)
☑ pH and soluble salts
☑ Organic matter content
5 Environmental and Service Conditions
NOTE The plant material specified shall be adapted to the project's climate zone and to the exposure, drainage, and soil conditions of its planting location. (5.1)
5.1.1Plant material shall be hardy to the project's USDA plant hardiness zone or colder.
5.1.2Plant material shall be acclimated to a growing region with conditions comparable to the project site, and stock grown in a markedly milder region shall not be substituted for hardy stock.
NOTE Seasonal high water table and subgrade permeability determine whether planting can drain freely and whether underdrains or soil replacement are required. (5.2)
5.2.1Subgrade permeability shall be verified by a percolation observation in representative tree pits before planting where the soil report indicates slow-draining soils.
5.2.2Where the seasonal high water table is within the depth set below of the bottom of the planting excavation, drainage accommodation shall be provided per the Drainage Accommodation section.
Zone 3
Zone 4
Zone 5
Zone 6
Zone 7
Zone 8
Zone 9
Per drawings
6 Planting Soil
NOTE Planting soil quality is the single largest determinant of long-term plant survival; soil that is too sandy drains and starves, while soil that is too high in clay holds water and excludes air. (6.1)
6.2 Imported Topsoil
6.2.1Imported topsoil shall conform to ASTM D5268 for gradation, organic matter, pH, and soluble salts and shall be free of deleterious material.
6.2.2Imported topsoil shall be a sandy loam to loam, free of subsoil, clay lumps larger than the size set below, stones, roots, and debris.
6.2.3Imported topsoil shall be free of noxious weed seed, herbicide residue, and contaminants at concentrations harmful to plant growth.
NOTE Specifying imported topsoil without ASTM D5268 gradation and organic-matter limits allows acceptance of sand-heavy fill or high-clay material unsuitable for plant growth; the gradation and organic-matter limits below are therefore mandatory acceptance criteria, not guidance. (6.2.4)
Sandy loam
Loam
Silt loam
Clay loam
57.5
5.56.57
Default: 6.5 pH
6.3 Sand, Silt, and Clay Fractions
6.3.1The sand fraction of the planting soil shall fall within the range set below as determined by ASTM D7928.
6.3.2The silt fraction of the planting soil shall fall within the range set below as determined by ASTM D7928.
6.3.3The clay fraction of the planting soil shall fall within the range set below as determined by ASTM D7928.
6.4 Soil Amendments
NOTE Soil amendment rates shall be derived from the project soil test results, not assumed; assumed rates either waste material or fail to correct the deficiency. (6.4.1)
6.4.2Compost used as a soil amendment shall be mature and stable as verified by ASTM D5975, and immature compost with high oxygen demand shall be rejected.
6.4.3Where required by the project, compost shall carry current USCC STA certification with TMECC test results.
6.4.4Lime or sulfur shall be applied at the rate required to bring the soil pH to the specified range based on the pre-work soil test, and the form of lime shall be selected per the test recommendation.
6.4.5Fertilizer shall be applied at the rate and analysis derived from the soil test, and slow-release nitrogen sources shall be used where rapid nitrogen release could damage new roots.
Very stable (mature)
Stable (mature)
Moderately stable
USCC STA certified
ASTM D5975 stability report only
Calcitic limestone
Dolomitic limestone
7 Subgrade Preparation
NOTE Compacted subgrade beneath planting soil is invisible after the work is done but stops roots and water as effectively as pavement; preparing the subgrade is as important as the planting soil placed over it. (7.1)
NOTE The subgrade shall be loosened so that roots and water can pass from the planting soil into the native soil rather than perch above a compacted layer. (7.2)
7.2.1Compacted subgrade in planting areas shall be scarified or ripped to the depth set below before planting soil is placed.
7.2.2The subgrade shall not be worked when it is frozen or saturated, because working wet soil destroys structure and worsens compaction.
7.2.3Compaction of the prepared subgrade shall not exceed the maximum density set below as verified by ASTM D1556, so that root penetration is not impeded.
NOTE Failing to test subgrade permeability before specifying planting risks discovering a high seasonal water table or compacted hardpan after bid, which forces costly change orders for underdrains or soil replacement; permeability verification is therefore required before placing planting soil. (7.2.4)
8090
Default: 85 % std. Proctor
8 Plant Material
NOTE Plant material shall be sound, healthy, vigorous, well-branched nursery stock free of disease, insect infestation, and mechanical injury, with a fully developed root system characteristic of the species. (8.1)
8.2.1Each plant shall be furnished in the root form specified for it: balled-and-burlapped, container, bare-root, or in-ground fabric bag.
8.2.2Bare-root stock shall be furnished and planted only during the dormant season.
8.2.3Container stock shall meet the container class specified per ANSI Z60.2; container class, not gallon volume alone, governs minimum acceptable size.
8.2.4Container stock shall not be root-bound, and stock with circling or kinked roots that cannot be corrected at planting shall be rejected.
Balled-and-burlapped (B&B)
Container-grown
In-ground fabric bag
Bare-root (dormant only)
8.3 Tree Size and Caliper
NOTE Caliper is measured at the height above the root flare set by ANSI Z60.2, and using the wrong measurement point is a common cause of acceptance disputes. (8.3.1)
8.3.2Tree caliper shall be measured 6 in. above the root flare for trees up to and including 4 in. caliper.
8.3.3Tree caliper shall be measured 12 in. above the root flare for trees larger than 4 in. caliper.
8.3.4Shade trees shall be furnished at the minimum caliper set below, and stock below that caliper shall be rejected.
8.3.5Multi-stem or clump trees shall meet the minimum aggregate caliper set below, measured per the method required by ANSI Z60.2 for clump stock.
8.3.6Tree height and spread shall be in normal proportion to the caliper for the species, and trees with sparse or one-sided canopies shall be rejected.
6 in. above root flare (trees up to 4 in. caliper)
12 in. above root flare (trees over 4 in. caliper)
8.4 Root Ball and Nursery Stock Sizing
8.4.1Root-ball diameter and depth for B&B stock shall conform to the diameter-to-caliper ratios in the ANSI Z60.2 tables for the caliper furnished.
8.4.2Root balls shall be firm, intact, and unbroken, and stock with cracked, loose, or air-pocketed balls shall be rejected.
8.4.3The wire basket and burlap on B&B stock shall be sound and shall hold the ball intact through handling and setting.
ANSI Z60.2 minimum ratio
ANSI Z60.2 minimum plus one size
8.5 Shrubs, Ground Covers, and Perennials
8.5.1Shrubs shall be furnished at the height or spread class specified and shall be well-branched from the base.
8.5.2Ground covers and perennials shall be furnished in the container size specified and shall be well-rooted but not root-bound.
8.5.3Plant spacing shown on the planting plan governs quantities; spacing is a layout dimension fixed by the drawings. ground cover spacing schedule 9 Plant Installation
NOTE How a plant is set in the ground in its first hour determines much of its survival; depth, backfill, and the handling of the root ball wrapping are the decisive details. (9.1)
9.2 Planting Depth
NOTE The top of the root flare shall be set at or slightly above finish grade, never below it; planting too deep is a leading cause of slow decline and trunk rot. (9.2.1)
9.2.2Each tree shall be set so that the top of the root flare is at finish grade or up to the tolerance set below above finish grade.
9.2.3The planting pit shall be excavated no deeper than the height of the root ball so that the ball rests on undisturbed or firmly tamped soil and does not settle.
9.2.4The planting pit shall be excavated to at least the width set below, measured as a multiple of the root-ball diameter, to loosen soil for lateral root growth.
1.53
Default: 2 × ball dia.
9.3 Root-Ball Wrapping and Basket Removal
NOTE Synthetic burlap does not decompose and will girdle roots; only natural jute burlap may remain in the pit, and synthetic wrapping shall be fully removed. (9.3.1)
9.3.2Synthetic or treated burlap shall be completely removed from the root ball before backfilling.
9.3.3The top third of natural jute burlap shall be cut away and folded down below grade after the ball is set and plumbed.
9.3.4The top of the wire basket shall be cut away to at least the depth set below after the ball is set, so that no basket wire remains within the upper root zone.
9.3.5All twine, rope, and tags shall be removed from the trunk and root flare before backfilling.
9.4 Backfill
NOTE In heavy clay subgrade, backfill amended with a high compost ratio creates a perched water table that drowns roots; current guidance favors unamended native soil backfill in most conditions. (9.4.1)
9.4.2Backfill shall be the unamended native soil excavated from the pit unless the soil report or the planting plan requires an amended backfill.
9.4.3Where amended backfill is specified, the compost shall not exceed the proportion set below by volume, so that a bathtub drainage condition is not created.
9.4.4Backfill shall be placed in lifts and lightly settled with water, not compacted, so that air pockets are eliminated without densifying the soil.
9.4.5Backfill shall not be mounded over the root ball or against the trunk.
Unamended native soil
Native soil with compost amendment
Imported planting soil
9.5 Anti-Desiccant
NOTE Wax-based anti-desiccants can clog the stomata of evergreens, so where an anti-desiccant is used it shall be a latex anti-transpirant type. (9.5.1)
9.5.2Where anti-desiccant is specified, it shall be applied to B&B broadleaf evergreens and conifers planted in fall or winter at the manufacturer's rate.
9.5.3Anti-desiccant shall not be applied when air temperatures are below 40°F.
Required for fall/winter evergreen planting
Permitted at Contractor option
Prohibited
10 Mulching
NOTE Mulch conserves soil moisture, moderates soil temperature, and suppresses weeds, but mulch piled against the trunk causes the rot it is meant to prevent. (10.1)
NOTE Mulch piled against the trunk in a volcano causes crown rot, bark decay, and structural root defects; a mulch-free zone at the trunk flare is therefore mandatory. (10.1.1)
10.1.2Mulch shall be placed over planting beds and tree rings to the depth set below, measured after settling.
10.1.3Mulch shall not exceed the maximum depth set below, because excessive mulch starves roots of oxygen and holds excess moisture against the stem.
10.1.4A mulch-free zone shall be maintained around each trunk or stem at the minimum setback set below; mulch shall never be placed against the trunk.
10.1.5Mulch shall be free of weed seed, sour odor, and contaminants, and shall be the type specified for the project.
Shredded hardwood bark
Double-ground wood chip
Pine fines
Pine straw
Stone / gravel
11 Tree Support
NOTE Staking restrains a tree until its roots anchor it, but a stake left too long girdles the trunk and prevents the trunk taper that builds strength; the removal date is as important as the installation. (11.1)
NOTE Leaving staking removal timing ambiguous results in stakes being left in place, girdling trees within two to three years; a mandatory removal date is therefore required, not optional. (11.1.1)
11.1.2Trees shall be staked or guyed only where required by exposure, caliper, or root form per ANSI A300; not every tree requires support.
11.1.3The support system shall be the type set below: two-stake, three-stake, or guy-wire per ANSI A300.
11.1.4Tree ties shall be broad flat webbing that will not cut into the bark; bare wire or wire in hose shall not be used in contact with the trunk.
11.1.5Ties shall be installed to allow the trunk to flex, not to hold it rigid, so that trunk taper develops.
11.1.6Staking and guying shall be removed no later than the schedule set below, and removal is the Contractor's responsibility through the establishment period.
None
Two-stake
Three-stake
Guy-wire (three-point)
Broad flat webbing strap
Arbor tie / belting
1224
1824
Default: 18 months
12 Pruning at Planting
NOTE Pruning at planting is limited to corrective cuts; removing too much canopy at planting starves the roots of the photosynthesis they need to re-establish. (12.1)
12.1.1Pruning at planting shall be limited to the removal of dead, broken, or crossing branches and to corrective structural cuts per ANSI A300.
12.1.2No more than 25% of the live canopy shall be removed in a single pruning season per ANSI A300.
12.1.3The leader shall not be cut, and the natural form of the species shall be preserved.
13 Turf Establishment
NOTE Turf may be established by sod for immediate cover or by seed for lower cost; each has its own preparation, timing, and acceptance criteria. (13.1)
13.2 Sod
13.2.1Sod shall be the cultivar or blend specified, machine-cut to a uniform thickness, strongly rooted, and free of weeds and disease.
13.2.2Sod shall be installed within the time set below after harvest so that it does not dry out or heat in the stack.
13.2.3Sod shall be laid in staggered joints, rolled to ensure contact with the soil, and watered immediately after installation.
Sod
Seed
Sod at high-visibility areas, seed elsewhere
Kentucky bluegrass blend
Tall fescue blend
Perennial ryegrass blend
Bermuda
Zoysia
St. Augustine
13.3 Seed
13.3.1Seed shall be the species and variety mix specified, tested for purity and germination, and free of noxious weed seed.
13.3.2Seed shall be applied at the rate set below in pounds of pure live seed (PLS) per 1000 SF.
13.3.3Seeded areas shall be protected and kept moist until uniform germination is achieved across the area.
210
46
Default: 5 lb PLS / 1000 SF
14 Drainage Accommodation
NOTE In poorly drained soils a planting pit becomes a sump that holds water around the roots; drainage accommodation moves that water away before it drowns the plant. (14.1)
14.1.1Where subgrade permeability or seasonal high water table requires it, drainage shall be provided for tree pits by the method set below.
14.1.2Perforated drain pipe placed in the pit bottom shall be routed to a positive outlet coordinated with the site storm drainage work. tree pit underdrain outlet NOTE Drainage accommodation in planting areas shall be coordinated with the storm drainage and earthwork so that planting underdrains discharge to an accepting system. (14.1.3)
14.1.4In paved areas, tree root volume shall be provided by structural soil or soil cells sized to the volume set below per tree, coordinated with the paving and utility work.
None (free-draining soil)
Perforated underdrain to outlet
Gravel sump in pit bottom
Structural soil / soil cells (paved areas)
Open-graded crushed stone
AASHTO M 147 graded aggregate
3001000
6001000
Default: 600 cu ft
15 Coordination with Utilities
NOTE A root ball reaching well below grade can strike a shallow utility that was never shown in plan view; locating utilities before digging prevents both damage and re-staking of trees. (15.1)
15.1.1Underground utilities shall be located and marked before any planting pit is excavated.
15.1.2Tree locations shall be adjusted in the field to maintain clearance from located utilities, and conflicts that cannot be resolved by minor adjustment shall be reported before excavation.
16 Establishment and Maintenance
NOTE The establishment period is the bridge between planting and a self-supporting plant; a gap in who waters during that period is where new plantings die. (16.1)
NOTE Failing to define when the establishment period starts produces disputes, because contractors and owners read the start date differently; the start event is therefore stated explicitly below. (16.1.1)
16.1.2The establishment period shall begin at the milestone set below and shall continue for the duration set below.
16.1.3The party responsible for establishment watering shall be the party set below, and where the owner's irrigation is the only water supply, the coordination of supply shall be resolved before the establishment period begins.
16.1.4Establishment watering shall be provided at the frequency and volume required to keep the root zone moist but not saturated, scaled to plant size and weather.
NOTE Distinguishing establishment watering from routine maintenance watering avoids a coverage gap when the owner's irrigation is the only supply; the responsibility split is therefore stated, not assumed. (16.1.5)
16.1.6The Contractor shall keep planting areas weeded, mulch maintained, and supports adjusted throughout the establishment period.
Date of planting
Substantial Completion
Owner acceptance of planting
12
Default: 1 growing seasons
Contractor
Owner
Contractor through establishment, then Owner
17 Warranty
NOTE The warranty puts the survival risk of new plantings on the party that selected, handled, and planted them, but only if its start date, survival threshold, and replacement terms are stated unambiguously. (17.1)
NOTE Omitting warranty language on re-planted stock leaves replacements with no warranty when the spec is silent; a warranty cycle on replacement material is therefore stated below. (17.1.1)
17.1.2Plant material shall be warranted for the duration set below, beginning at the milestone set below.
17.1.3Plant material shall be considered acceptable at the end of the warranty period if it meets the minimum survival and condition threshold set below, with no dieback exceeding 25% of the canopy.
17.1.4Plants that are dead, declining, or below the survival threshold at the end of the warranty period shall be replaced at no cost with material of the originally specified species and size.
17.1.5Replacement plants shall carry an additional warranty cycle of at least the duration set below from the date of replacement.
17.1.6Warranty replacement shall include all incidental soil preparation, mulch, and support required to install the replacement plant.
1224
1224
Default: 12 months
Substantial Completion
End of establishment period
Owner acceptance of planting
18 Delivery, Storage, and Handling
NOTE Plant material is alive and perishable; most planting losses that trace back to handling happen between the nursery and the pit, not after planting. (18.1)
18.1.1Plant material shall be protected from drying wind and sun during transport, and exposed root balls shall be covered.
18.1.2Plant material shall be handled by the root ball or container, never by the trunk or stems, so that the root ball is not loosened.
18.1.3Plant material that cannot be planted on the day of delivery shall be heeled in or stored with the root balls protected and kept moist.
18.1.4Bare-root stock shall be kept moist and protected from freezing and drying at all times until planted.
18.1.5Topsoil and amendments shall be stored so that they do not become contaminated, waterlogged, or mixed with subsoil or debris.