Colorado State University Extension and the Colorado State Forest Service publish Fact Sheet 6.305 for Colorado's WUI and varied ecosystems. FireApproved exposes all 114 exact source owners at Colorado publication scope while retaining score, elevation, water, and Idaho-carrier lineage. Publication scope is not suitability for every Colorado site or zone.
Marin County (CA footprint); partial normalized coverage · 2019-01-01
The publication is explicitly limited to plants common to Marin County. FireApproved publishes 104 exact owners as Marin regional context while retaining its placement, spacing, irrigation, and maintenance boundary. It is not statewide California guidance or parcel suitability.
Southern Idaho (ID footprint); partial normalized coverage · 2013-11-08
The official database labels itself "For Southern Idaho" and describes Idaho residents at the urban-rangeland interface. FireApproved publishes 419 existing plant owners that cite its scored rows. This bounded Southern Idaho scope is regional context, not statewide coverage or a conclusion that the score transfers unchanged to every Idaho site.
King County's current wildfire page links this list for the Puget Sound Basin. FireApproved publishes 82 exact source owners as basin context, not statewide Washington guidance or a site-specific recommendation.
The UC Forest Products Laboratory says the guide covers properties of common California landscaping plants and was prepared for California fire agencies. FireApproved publishes 130 exact owners at historical California publication scope. The report is a 1997 compilation, not a current endorsement, site rating, or independent test of every row.
Michigan State University Extension Bulletin E2948 is explicitly a list of wildfire-resistant landscape plants for Michigan and includes a Michigan-native field. FireApproved publishes 221 exact GBIF owners from 226 represented source rows and holds 15 complex or non-exact rows. This dated publication scope is not a current site-suitability determination.
The April 2022 MontGuide explicitly presents fire-resistant species adapted to Montana. FireApproved publishes 92 exact plant records from the source while retaining excluded genus, family, and unresolved rows; the guide itself says not every listed species grows in every part of the state.
Willamette Valley (OR footprint); partial normalized coverage · 2015-02-01
OSU Extension says EM 9103 highlights fire-resistant plants that thrive under Willamette Valley growing conditions. FireApproved publishes 172 exact owners only as valley context. The guide shares the PNW 590 lineage and is not a second independent vote or statewide site clearance.
The October 2023 joint Pacific Northwest Extension publication explicitly names Oregon, Washington, and Idaho and publishes more than 150 plant profiles. FireApproved has normalized 155 exact plant records from the source; publication scope does not assert that every listed plant suits every site within the three states.
University of Nevada Cooperative Extension compiled plants suited to Nevada climate zones and reported favorably by at least two upstream firewise lists. FireApproved publishes 126 exact source owners at Nevada publication scope. The source explicitly makes no independent flammability determination, so these rows remain corroborative.
Utah State University Extension states that this fact sheet selects examples for Utah landscapes and that they require proper placement and maintenance. FireApproved publishes 83 exact source owners at Utah publication scope. The table is not a site-specific planting clearance.
Eastern Washington (WA footprint); partial normalized coverage
Washington DNR publishes the guide for Eastern Washington and says it compiles plants from other Firewise documents that are likely to thrive there. FireApproved publishes 46 exact owners only as eastern Washington context. The rows are corroborative, not empirical or statewide.
2. Why this plant is relevant here
State distribution
Documented in AK, CA, CO, ID, OR, PA, WA.
Native range
Current cited native range in AK, CA, CO, OR, WA.
Introduced / established
No introduced or established row is normalized; that does not prove native status.
USDA hardiness
4 applicable cited hardiness statements overlap but have different boundaries; compare each complete source row.
3. Legal, ecological, and broader status
Legal-list status
Set a location for an exact legal-list result; source silence is not clearance.
Seed-list status
Set a location to compare the separate state noxious-weed seed layer.
Reported invasive here
No ecological invasive report is normalized; that does not prove noninvasiveness.
Broader regional context
Aggregate AK, HI, and L48 evidence is shown only as regional context, never as an exact-state finding.
Federal context
Federal designations remain separate from state legal-list results.
How to read this page
The status above is computed from the cited rows below: independent recommendations can support a fire-resistant result, an avoid row can produce keep-away, and disagreement stays visible as conflict. Placement notes preserve each source’s own scheme rather than translating unlike rules into one scale. This is evidence about a plant, not permission to plant it in every part of the defensible space; Zone 0 remains noncombustible.
Applicable source statements overlap but have different boundaries; compare each source
Mature height
~0.9 ft
Water need
moderate
Current cited native range
AK, CA, CO, OR, WA
Grows in
AK, CA, CO, ID, OR, PA, WA
Rated in
British Columbia; California; Colorado / Rocky Mountain Front Range; Marin County, California +11
Family
Plumbaginaceae
Evidence
15 cited sources
Native and introduced range evidence
These are exact U.S. botanical-area records from the cited range source. Native and
introduced describe biogeographic relationship, not fire performance or planting approval.
Doubtful and extinct rows stay visible but do not count as current presence.
The lossless worldwide derivative is retained once in the research corpus; object pages repeat only exact U.S. areas needed by the local lens. The JSON twin carries the same page assertions.
Plant hardiness evidence
These values describe the plant source. Your ZIP zone comes from the separate 2023 USDA
Plant Hardiness Zone Map. Whole-zone values stay whole-zone, and a single unresolved value
is not treated as a tolerance range. Different source boundaries stay separate: overlapping
statements are compared independently, while only ranges with no shared zone are called a conflict.
Placement rules below use each source's own distances or named zones, tied to its rating.
They are not interchangeable with the directory's current Zone 0 guidance.
Fire Resistance of Plants Master Database: plantable at 30' from home [Idaho minimum planting distance] (with its recommendation)
FireSmart BC Plant Program: suitable for HIZ intermediate zone (10-30 m) [FireSmart BC Home Ignition Zone] (with its recommendation)
Fire-Resistant Plants for Oregon Home Landscapes: Oregon [osu-frn6-oregon-regions] (with its recommendation)
Fire-resistant Landscape Plants for the Willamette Valley: Sea Thrift profile (PDF page 87) [osu-em-9103-profile] (with its recommendation)
Ignition-Resistant Landscape Plants: suitable for defensible-space zones 1-2 (score 8+) [CSU defensible-space zone] (with its recommendation)
Defensible Space Landscaping in the Urban/Wildland Interf…: Chapter 4, Landscape Vegetation Database [ucfpl-1997] (with its recommendation)
The evidence
Grouped by what each source concluded. Primary evidence rated the plant itself
(a lab, field program, or original curation); corroboration compiled or
republished another source's rating and resolves to its root lineage.
“Fire-Resistant Plant Materials for Oregon”
· condition: green
Armeria maritima (Sea thrift) is listed under “Perennials 18 inches or taller”. The guide says most listed plants require some irrigation during Oregon's dry summer months and must be maintained in a healthy condition.
“Choose the right perennial plants for your fire-resistant landscape”
· original source
The Sea thrift profile prints Armeria maritima. The gallery points to PNW 590 for complete details.
Ignition-Resistant Landscape Plants (Fact Sheet 6.305) — Colorado State University Extension / Colorado State Forest Service (Wildfire Mitigation Series) · 2025 · original sourcePrimary evidenceField programlineage: idaho-tree resolves to Fire Resistance of Plants Master Database
“ignitability score 8 of 10”
· score 8 (idaho-0-10)
CSU 6.305 table lists Armeria maritima (sea thrift) with the preserved ignitability score.