Allegheny County, PA Tree Protection: Parkway Planting (2026)
Key Facts
- Section
- § 780-512.D
- Large tree caliper
- 2.5-3.0 in. DBH
- Small tree spacing
- 25 ft on center
- Applies to
- New subdivisions/land developments
Summary
Allegheny County requires street trees along both sides of new subdivision and land development streets, with minimum trunk calipers and spacing set by tree size under the county land-development code.
Street trees shall be provided along the entire length of the street right-of-way on both sides of the street if the street lies within the development.
(2) Street trees in residential subdivisions shall be located within five feet of the right-of-way and in nonresidential developments between the right-of-way and the building line. An easement shall be granted to the municipality for the purpose of maintaining the trees, and a restrictive covenant shall be placed in the deed for the property prohibiting removal of the trees by the property owner.
(3) Street trees shall be located so as not to interfere with the maintenance of utilities, required sight distances and visibility of street and traffic signs.
(4) The species chosen shall be appropriate to the location. Factors such as microclimate, soils, habit of growth, salt, air pollution and disease tolerance, proximity of sidewalks and overhead utility lines, and social conditions (likelihood of soil compaction, vandalism, damage by dogs, deer, etc.) shall be considered. Tree species shall be selected that do not have root structures that may damage adjacent sidewalks or utilities.
(5) Street trees shall have the following minimum calipers at the time of planting:
(a) Large trees, defined as those trees whose height will ultimately exceed 40 feet, shall have a minimum caliper of 2.5 inches to 3.0 inches DBH.
(b)
Official source re-checked September 7, 2026: no newer edition of the code had been published (publisher’s edition: rev 4857026; v12 updated 2024-06-04; through 06-04-2024).
Full Breakdown
Section 780-512.D requires street trees along the full right-of-way of streets within a covered subdivision or land development, sized and spaced by category: large trees (over 40 feet mature height) need 2.5-3.0 inch caliper, medium trees 2.0-2.5 inches, small trees 1.5-2.0 inches, with spacing tied to mature canopy spread. Applies where the county Department of Economic Development reviews the plan.
Violations & Fines
Street tree plantings that miss the required caliper or spacing standards must be revised before the Department of Economic Development grants final plan approval.
Frequently Asked Questions
Does Allegheny County set street tree size requirements?
Where must street trees be placed?
Sources & Official References
Other rules in Allegheny County
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