Enter your ZIP to see whether this is legal to plant in your state, and whether it survives your winter.
Yes, purple cistus is rated fire resistant, though the primary evidence supporting that verdict is limited.
Six findings favor the shrub. A joint extension source from Oregon State, Washington State, and the University of Idaho lists it as fire resistant. Oregon State also profiles Cistus x purpureus for fire-resistant landscaping in the Willamette Valley and includes Cistus purpureus in a Pacific Northwest educational gallery. The ACT Government marks it “Fire Retardant: Yes.” In California, the Diablo Firesafe Council places it among plants receiving favorable fire-performance ratings in at least three references.
The agreement comes mostly from expert selections and compiled lists, rather than a single shared test. FireSmart BC approves purple cistus as fire resistant but flags it as needing more research. The Diablo Firesafe Council also says that ranking terms in its underlying references were mostly undefined. Those qualifications leave uncertainty behind an otherwise consistent fire-resistant rating.
Purple cistus is a shrub in the Cistaceae family, with a stated range of USDA zones 7a to 10b. For a homeowner choosing plants, the evidence supports treating it as a fire-resistant option while recognizing that FireSmart BC still calls for further study.
Form
shrub
Rated in
Australian Capital Territory, Australia; British Columbia; California; OR/WA/ID +3
On this lot
1. Fire evidence and conditions
Fire evidence
Fire-resistant — location does not change the cited classification.
The guide presents itself as fire performance ratings for common landscape plants in a fire-prone California setting. FireApproved publishes 104 exact owners as republished California context. It is not an independent rating, a current endorsement, 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.
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.
2. Why this plant is relevant here
State distribution
Documented in ID, OR, WA.
Native range
Introduced / established
USDA hardiness
Documented range 7–10.
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.
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.
7–10 explicit range · whole zone precision · source stated
Source taxon: Cistus purpureus · exact match.
Source location: Orchid rockrose profile, USDA hardiness zones field.
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 60' from home [Idaho minimum planting distance] (mid-scale rating)
Fire-resistant Landscape Plants for the Willamette Valley: Orchid Rockrose profile (PDF page 140) [osu-em-9103-profile] (with its recommendation)
Canberra Plant Selector: filtered result page 17 [canberra-selector] (with its recommendation)
Fire Performance of Common Plants: Table 1 (favorable in 3 or more references) [diablo-guide-to-plants-three-reference-vote] (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.
The live Canberra Plant Selector marks “Cistus x purpureus” as “Fire Retardant: Yes.”
Fire Performance of Common Plants (Guide to Plants) — Diablo Firesafe Council · live page captured 2026-08-29 · original sourceCorroborationMirrorlineage: ucfpl-berkeley resolves to Defensible Space Landscaping in the Urban/Wildland Interface: A Compilation of Fire Performance Ratings of Residential Landscape Plants
“Table 1: favorable fire performance rating in 3 or more references (refs 25,30,53)”
The Diablo Firesafe Council Guide to Plants lists Cistus purpureus (Orchid rockrose, Purple rockrose) as shrub, evergreen, in Table 1: plants with a favorable fire performance rating in 3 or more references. The guide cites 3 of its 57 numbered references for this row (25,30,53). The guide states the ranking terms in its underlying references were mostly undefined and makes no attempt to rank within the list, and that fire performance is compromised without maintenance.
