Pierce County, WA Tree Protection: Parkway Planting (2026)
Key Facts
- Spacing standard
- 1 tree per 30 lineal feet of road frontage
- Alternative small-lot rule
- 1 canopy tree if lot under 60 feet wide
- Alternative mid-lot rule
- 2 canopy trees if lot 60-100 feet wide
- Minimum mature height
- 20 feet at maturity
- Root barrier trigger
- Required within 5 feet of pavement/curb/sidewalk
- Setback if kept off ROW
- Within 15 linear feet of right-of-way
Summary
Unincorporated Pierce County requires street trees along both sides of urban roads under PCC 18J.15.050, spaced at one tree per 30 lineal feet of frontage. Developers pick between right-of-way planting or an alternative per-lot canopy-tree count, with root barriers required near pavement and curbs.
A. Applicability. Street trees shall be installed along both sides of all urban roads in urban areas only. Flexibility may be allowed when requirements for low impact development (LID) best management practices (BMPs) preclude street trees on both sides of a road. ... C. Standards. ... 2. Street trees shall be installed along each side of streets at a rate of 1 per 30 lineal feet of roadway, excluding intersections. Clustering is permitted to allow for driveways. Spacing shall be the minimum required by the selected species pursuant to the street tree plan, but in no case shall spacing be greater than 30 feet for individual trees or 100 feet between clusters. ... 4. Placement. Street trees shall be placed within the public or private road right-of-way unless there is a safety reason not to as determined by the County Engineer. In that event, the street tree requirement shall be met by placing trees on private property within 15 linear feet of the road right-of-way. 5. Minimum mature height shall be 20 feet.
Official source re-checked September 8, 2026: no newer edition of the code had been published (publisher’s edition: current through Ordinance 2026-515, and legislation passed through May 26, 2026).
Full Breakdown
050 governs parkway (street) tree planting for new development in unincorporated Pierce County. Street trees are required along both sides of all urban roads in urban areas; the County allows flexibility only when low impact development stormwater best management practices preclude trees on both sides. 2) sets spacing at one tree per 30 lineal feet of roadway, excluding intersections, with clustering permitted around driveways; individual tree spacing cannot exceed 30 feet, and cluster spacing cannot exceed 100 feet. 3), lots under 60 feet wide must install at least one large-canopy street tree, lots 60 to 100 feet wide must install at least two, and corner lots must meet those rates on each road frontage; the Director sets rates for lots over 100 feet wide or shared common areas.
Placement defaults to the public or private road right-of-way; if the County Engineer finds a safety reason to keep trees out of the right-of-way, they must instead go on private property within 15 linear feet of it. 100. Any tree planted within 5 feet of pavement edge, curbing, sidewalk, or required parking must carry a root control barrier of galvanized metal or plastic extending at least two feet below grade. In the Employment Corridor, Neighborhood Corridor, Towne Center, and Urban Corridor zones, potted or containerized trees are allowed as an alternative under subsection D.
9) by installing all trees before final plat approval, bonding a financial guarantee before final plat, or, for single-family and two-family homes, showing trees on the site plan with installation required before building permit final inspection.
Violations & Fines
Enforcement runs through the plat and building permit process rather than standalone citations: the Planning and Public Works Department will not grant final plat approval or a building permit final inspection until required street trees are installed or a financial guarantee is posted. Missing root control barriers or undersized/wrong-species plantings can trigger a corrective plan requirement before final sign-off, since compliance with PCC 18J.15.050 is a condition of project completion.
Frequently Asked Questions
Do all Pierce County subdivisions have to plant street trees?
How far apart do street trees need to be in Pierce County?
Can Pierce County require a root barrier around a street tree?
When must street trees be installed before a project can close out?
Sources & Official References
Other rules in Pierce County
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