Flagstaff, AZ Landscaping Rules: Native Plants (2026)

Flagstaff Zoning Code § 10-50.60.060, Hydrozones, divides every landscape plan into up to three water-use zones, and Hydrozone 3, the native zone, is the code's dedicated allowance for native and naturalized planting. Under Table 10-50.60.060.A, Hydrozones, and its endnote, a site qualifies for Hydrozone 3 only when a minimum of 80 percent of the plant selection is native plants, with the remaining share allowed to be naturalized plants and vegetation; the section text adds that native vegetation preserved on-site during construction also counts toward the zone. Because Hydrozone 3 plants have the greatest drought tolerance of the three zones, the code says they require little, if any, supplemental water once established except in times of drought, and a permanent or temporary irrigation system in that zone is permitted but not mandatory.

This native-plant allowance works together with the rest of Division 10-50.60. Plant selection still has to come from the City of Flagstaff Landscape Plant List in Appendix 3, and the landscape plan submitted for concept and preliminary review has to identify which hydrozone applies to each planting area. A site can mix a small, more heavily watered Hydrozone 1 oasis near a building entrance with a Hydrozone 3 native zone on the rest of the lot, but turf and non-drought-tolerant plants are confined to the oasis and cannot be counted toward the native zone's 80 percent native-plant threshold.