Ada County, ID Landscaping Rules: Native Plants (2026)
Key Facts
- Governing section
- Ada County Code 8-3-7
- Turf cap
- Bluegrass/high-water plants max 50% of area
- Applies to
- Projects needing master site plan review
- Exempt
- Rural base district permitted/accessory uses
- Tree removal offset
- 1-3 replacement trees by caliper size
- Compliance deadline
- Next planting season after occupancy
- Default penalty
- Up to $1,000 fine/6 months or $100 infraction
Summary
Ada County's zoning code caps traditional bluegrass lawn at 50% of any landscape area and directs developers toward native, low-water plant material on projects that require master site plan review. The standard sits in Ada County Code section 8-3-7 and applies countywide outside the exempt rural base districts.
7. All landscaping shall be designed to be waterwise per the suggested plant list provided by Ada County.
a. The use of native and low-water and native plant material is highly encouraged.
b. Plants shall be grouped into hydrozones based on similar water needs to minimize the unnecessary use of water plants with low water needs.
c. High water-use plant material such as bluegrass lawn shall comprise no more than fifty percent (50%) of any landscape area.
Official source re-checked September 7, 2026: no newer edition of the code had been published (publisher’s edition: 2026 S-15: Code current through: Ord. 1018, passed 3-24-2026).
Full Breakdown
Ada County Code section 8-3-7 (Landscaping) governs how much of a developed site can be planted in thirsty turf versus native or drought-tolerant material. " A landscape and screening plan showing the plant list, quantities and mature growth at 75% size must be submitted as part of the master site plan under 8-3-7(C)(1), and within an area of impact that plan must be prepared by a licensed landscape design professional. Section 8-3-7(D)(2) also protects existing native vegetation: it must be retained wherever possible, and existing stands can be credited in lieu of new plantings if they meet the section's intent.
Removed trees six inches in caliper or larger trigger mandatory replacement under Table 8-3-7-1: a 6"-12" tree needs one 3" replacement, a 12"-24" tree needs two, and anything 24" or larger needs three replacement trees. The section does not apply to every parcel: subsection 8-3-7(B)(2) exempts all principally permitted and accessory uses in the rural base districts listed in the Section 8-2-23 use table, though the Board can impose or modify these standards on a conditional use in those districts through the Chapter 6 conditional use process.
Compliance is checked at certificate of occupancy, and installation must be finished by the start of the next planting season for that species, with the Director able to grant one additional planting season for circumstances beyond the applicant's control.
Violations & Fines
Ada County Code section 8-3-7 does not carry its own penalty clause, so a violation falls under the code's general penalty at section 1-4-1: a fine of up to $1,000 and/or up to six months imprisonment for a straight misdemeanor, or a $100 fine with no jail time if Development Services cites the failure as an infraction. Section 1-4-2 treats an unmet landscaping duty as continuing, meaning each day the required plant material, replacement trees, or 50% turf cap remains out of compliance can count as a separate offense.
Frequently Asked Questions
Can I landscape a new Ada County development entirely with native plants?
Does the 50% turf cap apply to my existing rural home?
Do I need a landscape architect for a native-plant plan in Ada County?
What happens if I remove a large native tree during construction?
Sources & Official References
Other rules in Ada County
Compare Ada County to another location·View the Idaho landscaping rules overview
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