Williamson County, TN Landscaping Rules: Native Plants (2026)

03: General Provisions of Article 15: Landscaping and Bufferyards governs every plant installed to satisfy the county's landscaping, bufferyard, streetscape, or parking-lot screening requirements. 03-1 minimum size requirements by plant type before they count toward compliance. Subsection (C), Native and Drought-Tolerant Vegetation, is the operative rule: at least 40 percent of all landscaping or bufferyard vegetation on a development must be native and/or drought-tolerant species, drawn from a list of acceptable plant materials the Community Development Department keeps and updates. 03-2, which caps how much of the total tree count on a site can be one species.

Subsection (E), Existing Vegetation, lets a developer count healthy, well-formed existing canopy trees, understory trees, and shrubs toward these requirements, provided the vegetation is fenced and protected before and during construction and kept in healthy condition afterward, so a wooded or already-native site does not have to plant over what it already has. Because these standards sit inside Article 15, they apply on top of, not instead of, the county's separate streetscape and bufferyard landscaping quantities, and are reviewed at site plan submission by the Community Development Department for unincorporated Williamson County parcels only.