Enter your ZIP to see whether this is legal to plant in your state, and whether it survives your winter.
Old man's whiskers is rated fire resistant, with regional planting support and matching Idaho and Colorado scores.
The scientific name Geum triflorum connects old man's whiskers with prairie smoke in the planting guides. The Pacific Northwest extension publication recommends it as prairie smoke. FireSmart BC prints both common names and places the species in its intermediate zone, providing a location qualification alongside its favorable selection.
Idaho's database assigns prairie smoke a fire-resistance score of eight. Colorado also prints eight, using a methodology it attributes to Idaho. This agreement follows a shared assessment approach rather than establishing that two separate burn experiments produced the same result.
Colorado's scale identifies ten as the least ignitable end, so eight is favorable without being its maximum score. The source also calls for maintenance, including water and control of dead-material accumulation. Use the regional guidance to compare prairie smoke with other planting choices, retaining FireSmart's zone advice and the upkeep that accompanies Colorado's numerical assessment.
Form
perennial
Mature height
~1.5 ft
Water need
moderate
Rated in
British Columbia; Colorado / Rocky Mountain Front Range; Fremont County, Wyoming; OR/WA/ID +3
On this lot
1. Fire evidence and conditions
Fire evidence
Fire-resistant — location does not change the cited classification.
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.
Dovetail applies the UF/IFAS flammability key to northeastern Minnesota natives and publishes placement for 38 exact source owners. FireApproved exposes those rows only as northeastern Minnesota regional context and preserves the 3-to-30-foot versus beyond-30-foot source placement.
Fremont County (WY footprint); partial normalized coverage · 2011-02-25
The source identifies itself as the Fremont County Firewise Plant List. FireApproved publishes its 92 exact source owners as Fremont County regional context. No methodology, current county endorsement, statewide Wyoming scope, or site-specific suitability is inferred.
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.
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.
2. Why this plant is relevant here
State distribution
Documented in AZ, CA, CO, IA, ID, IL, MI, MN, MT, ND, NM, NV, NY, OR, SD, UT, WA, WI, WY.
Native range
Current cited native range in AZ, CA, CO, IA, ID, IL, MI, MN, MT, ND, NM, NV, NY, OR, SD, UT, WA, WI, WY.
Introduced / established
USDA hardiness
3 applicable cited hardiness statements overlap but have different boundaries; compare each complete source row.
3. Legal, ecological, and broader status
Legal-list status
Seed-list status
Reported invasive here
Broader regional context
Federal context
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.
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.
Source location: PlantCharacteristics record 89830, Temperature, Minimum (°F).
Where its sources say to plant it
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)
Landscaping for Wildfire Defensible Space in Northeastern…: plantable 3-30 ft from a building [Dovetail Partners 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)
Ignition-Resistant Landscape Plants: suitable for defensible-space zones 1-2 (score 8+) [CSU defensible-space zone] (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.
“Choose the right perennial plants for your fire-resistant landscape”
· original source
The Prairie smoke profile prints Geum triflorum. 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 Geum triflorum (prairie smoke) with the preserved ignitability score.
“Fremont County Firewise Plant List — Geum triflorum — Prairie Smoke”
Listed in the source's Ground Covers section; the page describes its listed Firewise plants as generally low-growing, low-debris, and relatively moist.
