Tree Planting, Establishment, and Species Selection
This domain tests species selection and planting practice from site analysis through establishment, with emphasis on details that determine whether a tree survives its first three years.
Core rules
- Right tree, right place: assess soil volume, texture, pH, drainage, compaction, overhead and underground conflicts, salt, and sun before choosing a species.
- Select for climate adaptation, pest resistance, non-invasiveness, and diversity at species, genus, and family level; a cultivar list tied to the local species list reduces monoculture risk.
- Nursery stock should meet ANSI Z60.1. Reject stock with circling roots, a buried root flare, or a trunk wound.
- The planting hole is two to three times the root ball width and no deeper than the root ball; the root flare sits at or slightly above grade.
- Remove the wire basket, burlap, and ties from the trunk; backfill with excavated soil; do not amend unless drainage requires it.
- Mulch 2 to 4 inches deep, kept off the trunk. Stake only when necessary and remove within one to two growing seasons.
Worked example
A 4 ft by 4 ft pit in compacted clay, 8 ft from overhead conductors. The site rules out a large-maturing shade tree. The plan: a small-maturing species or cultivar, bare-root 1.5-inch caliper stock, a planting hole 3 ft wide, root flare at grade, and expanded soil volume using structural soil under adjacent pavement, since a 4 ft pit supplies far less than the roughly 300 cubic feet a small tree needs to reach maturity. Establishment watering continues for two to three years.
Traps
Planting at the nursery depth rather than at the root flare. Amending backfill as a default. Leaving stakes and ties for years. Volcano mulch. Assuming a larger caliper establishes faster; it usually transplants harder.