Enter your ZIP to see whether this is legal to plant in your state, and whether it survives your winter.
Yes, lilacbush is consistently listed as fire resistant, though its support comes mainly from expert and agency plant lists.
Six assessments reach the same conclusion. Oregon State, Washington State and University of Idaho extension services recommend Aubrieta deltoidea for fire-resistant landscaping, as do Washington’s Department of Natural Resources, FireSmart BC, and agencies in Maryland, New Jersey and West Virginia.
That agreement spans the Pacific Northwest, British Columbia and three eastern states, so it is more than a single local recommendation. Still, most sources use a yes-or-no plant list rather than a comparative test. The eastern agencies describe their listed plants as relatively resistant and better able to resist wildfire ignition, but provide no plant-specific method. FireSmart BC approves lilacbush while also flagging it as needing more research. The fair reading is fire resistant, but supported by limited primary evidence.
Lilacbush is a groundcover in the Brassicaceae family and is introduced in California. The joint Pacific Northwest extension guide places it in USDA zones 4a through 8b, while an Oregon State profile prints zones 4 through 9. These sources support choosing it as a fire-resistant groundcover, but FireSmart BC’s caution is reason not to treat the label as settled experimental proof.
Form
groundcover
Rated in
British Columbia; Maryland, New Jersey, and West Virginia; OR/WA/ID; Oregon (Willamette Valley) +2
On this lot
1. Fire evidence and conditions
Fire evidence
Fire-resistant — location does not change the cited classification.
British Columbia; Maryland, New Jersey, and West Virginia; OR/WA/ID; Oregon (Willamette Valley); Pacific Northwest (Oregon / Washington / Idaho); eastern WA
Maintenance
Typed publication scope: 6 scopes across 4 cited fire sources
Maryland Forest Service says the list contains plants that can be grown in Maryland and identifies Maryland natives. FireApproved publishes 169 exact source owners from the 180 printed rows; an unrepresentable form and duplicate-owner rows are not broadened. The list calls itself non-comprehensive and does not establish suitability for every Maryland site.
NJ; partial normalized coverage
New Jersey DEP publishes a state edition saying the listed plants can be grown in New Jersey and are relatively resistant to fire. Its same 180 printed taxon occurrences map to the 169 conservative owners already normalized for the template family. The list is non-comprehensive and does not establish suitability for every New Jersey site or override the Pinelands Commission's separate placement and fuel-break rules.
WV; partial normalized coverage · 2026-08-26
West Virginia Division of Forestry publishes a state edition saying the listed plants can be grown in West Virginia and are relatively resistant to fire. Its same 180 printed taxon occurrences map to the 169 conservative owners already normalized for the template family. The list is non-comprehensive and provides no comparative or site-specific rating.
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.
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 CA, ID, MO, OR, UT, WA.
Native range
Introduced / established
2 sourced range or established records. This is not an invasive warning.
USDA hardiness
2 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.
4–8 explicit range · whole zone precision · source stated
Source taxon: Aubrieta deltoidea · exact match.
Source location: False rock cress 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-resistant Landscape Plants for the Willamette Valley: Rock Cress profile (PDF page 20) [osu-em-9103-profile] (with its recommendation)
Fire-resistant plant profile galleries: False rock cress — Aubrieta deltoidea [osu-2023-groundcovers-gallery] (with its recommendation)
Firewise Landscaping Plants: Herbaceous Annuals and Perennials [Maryland Firewise plant-form tables] (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.
Listed as Aubrietia deltoidea (False Rock Cress). The source says listed species exhibit stronger resistance to ignition by wildfires. Source comments: Prefers full sun
