Enter your ZIP to see whether this is legal to plant in your state, and whether it survives your winter.
Yes, white alder is rated fire resistant, though the support comes mostly from compiled guidance rather than scientific fire trials.
Five published recommendations point in the same favorable direction. Montana State University Extension includes white alder among fire-resistant plants adapted to Montana, while Nevada forestry and extension guidance assigns it a low fire-hazard rating. Another Nevada extension compilation includes the tree because at least two western sources reported it as fire resistant or favorably rated. California compilations agree: the University of California Forest Products Laboratory found recommendations in five references, and the Diablo Firesafe Council reports favorable ratings in five cited references.
The agreement is useful, but its basis matters. The Lake Tahoe guidance calls its ratings rough estimates and says they were not derived from scientific trials. The California Forest Products Laboratory likewise warns that many underlying plant lists lacked a scientific basis and used terms that were not clearly defined. Several institutions therefore agree on the practical classification, but much of that agreement traces back to expert and compiled lists rather than direct experiments on white alder.
White alder is a high-water tree in the birch family, reaching about 65 feet at maturity. Its fire-resistant classification is a reasonable guide for plant selection, not a promise that the tree cannot burn. The sound reading is favorable but measured: white alder belongs among fire-resistant choices, with limited primary evidence behind that label.
Form
tree
Mature height
~65 ft
Water need
high
Rated in
California; Lake Tahoe Basin, Nevada and California; Montana / Northern Rockies; Nevada / Great Basin +1
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.
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.
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.
Nevada Division of Forestry and University of Nevada Cooperative Extension publish Bulletin 06-01 for the Lake Tahoe Basin and vicinity. FireApproved publishes 83 exact rated owners as basin context across Nevada and California. Rough estimates are not statewide or site ratings.
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.
2. Why this plant is relevant here
State distribution
Documented in CA, ID, MT, NV, OR, WA.
Native range
Current cited native range in CA, ID, MT, OR, WA.
Introduced / established
USDA hardiness
Documented minimum 4b; no upper limit is documented.
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 69923, 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: 70 ft minimum planting distance on flat terrain [Idaho minimum planting distance] (mid-scale rating)
Home Landscaping Guide for Lake Tahoe and Vicinity: Fire Hazard column: low [tahoe-guide-2006] (with its recommendation)
Defensible Space Landscaping in the Urban/Wildland Interf…: Chapter 4, Landscape Vegetation Database [ucfpl-1997] (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.
Table 1's Fire Hazard column prints “low” for this taxon. The guide calls the rating a rough estimate of potential flammability, not a result of scientific trials. Its footnote says plants that turn brown often become high fire hazards and tells readers to mow grasses and forbs when they begin to turn brown.
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 9,11,17,25,53)”
The Diablo Firesafe Council Guide to Plants lists Alnus rhombifolia (White alder) as tree, deciduous, in Table 1: plants with a favorable fire performance rating in 3 or more references. The guide cites 5 of its 57 numbered references for this row (9,11,17,25,53). 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.
