Norman, OK Invasive Plant Rules: Tree-of-Heaven Removal (2026)

Appendix D of the Norman Code of Ordinances divides landscaping species into two sections. Section A lists species that 'DO NOT MEET the required cultural characteristics suitable for Norman's climate and soil composition,' and Ailanthus altissima, Tree-of-Heaven, is one of only two trees on that list carrying the code's own flag: 'Invasive species. Will survive any condition.' The listing sits inside the height-and-spread table for Section A, where Tree-of-Heaven is recorded at a mature height of 30 to 60 feet and a spread of 30 to 40 feet.

The list matters because of Residential Code Section R328.1, added to Chapter 6 for building permits issued after May 12, 2008: within urban residential plats, a new single-family or two-family lot must plant at least one tree (two on lots over 10,000 square feet, one per frontage on corner lots), and 'trees must be selected from the plant list in section B of appendix D.' Section B is the 'DO MEET' list of climate-suited, largely Oklahoma Proven species. Because Tree-of-Heaven sits in Section A, not B, it cannot be the tree a builder plants to satisfy R328.1, regardless of the species' well-known tolerance for poor soil, drought, and disturbed ground, the very trait the code cites as the problem.

The exclusion runs only to the mandatory new-construction planting; the code does not direct removal of Tree-of-Heaven already established on a lot, and the planted trees required under R328.1 must carry species identification tags until the certificate of occupancy is issued.