Weld County, CO Landscaping Rules: Native Plants (2026)

Division 6 of Chapter 23, Article V establishes the I-25 Overlay District, an area mapped in Appendix 23-H that layers extra design standards onto any development there requiring Site Plan Review, Use by Special Review, a Special Review Permit for a major public utility facility, or a zoning permit. 2 is the native-species directive: designers must use a variety of species and strive to maximize the use of native species, turning to regionally adapted, noninvasive plants only when a native species will not suit the intended use or appearance, with Appendix 23-I supplying a partial list of plants native or adapted to the Front Range.

The same subsection A names four species barred outright from any I-25 Overlay landscape plan: cotton-bearing cottonwood, Siberian elm, Chinese elm and Tree of Heaven, plus any listed noxious weed. Subsection A also folds in xeriscape water-conservation principles, drought-tolerant turf selection over bluegrass, mulch, soil improvement and efficient irrigation design, and requires the applicant's Landscape Plan to be submitted to the Department of Planning Services and to show that existing trees of four-inch caliper or larger, or clustered groups of three or more smaller trees, are preserved wherever feasible during construction.

The requirement is a development-review standard, not a homeowner mandate: it attaches when a project inside the mapped I-25 Overlay District goes through one of the listed County approval processes.