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'Fine Line® Improved' buckthorn

Rhamnus frangula (accepted: Frangula alnus) · Rhamnaceae · all Rhamnus records · syn. Rhamnus frangula

Your local evidence lens

Separate evidence questions, never one approval badge

Set a ZIP to compare this record with state distribution, native range, USDA hardiness, and invasive records.

A genus split is not a placement verdict. Set a ZIP to read the local documented split.

1. Fire evidence and conditions

Fire evidence
Fire-resistant — location does not change the cited classification.
Fire-performance conditions
1 condition stated in cited fire-evidence rows.
Fire ecology context
No section-reviewed fire-ecology context is normalized.
Placement evidence
4 source placement records; source schemes remain separate.
Evidence regions
British Columbia; OR/WA/ID; Ohio / Midwest; Oregon (Willamette Valley); eastern US; eastern WA; north-eastern and mid-Atlantic United States; southern Idaho / Intermountain
Maintenance
No sourced horticultural maintenance assertion is normalized; fire-test conditions do not supply maintenance advice.
Typed publication scope: 6 scopes across 6 cited fire sources
  • Combustion characteristics of north-eastern USA vegetation tested in the cone calorimeter · Official scoped edition
    • Northeastern and mid-Atlantic study sites (ME, MD, MA, NY, VA footprint); partial normalized coverage · 2007-08-20

      The authors collected foliage and twigs across study sites in Maine, Maryland, Massachusetts, New York, and Virginia, then conditioned and tested the samples in a cone calorimeter. FireApproved publishes 37 exact source owners only as multi-state laboratory context. The source does not establish that every taxon was sampled in every named state, whole-plant behavior, landscape suitability, or state planting guidance.

  • Fire Resistance of Plants Master Database · Official scoped edition
    • 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.

  • Firewise Landscaping (OSU Extension Bulletin 921) · Official scoped edition
    • OH; partial normalized coverage · 2006-03-01

      Ohio State University Extension Bulletin 921 is an Ohio publication that describes Ohio fire seasons and landscape conditions and labels nativity to Ohio. FireApproved publishes 352 exact source-owning plant records from its eight rated tables. This historical publication scope does not assert current extension endorsement or that a listed plant suits every Ohio site.

  • Fire-resistant Landscape Plants for the Willamette Valley (EM 9103) · Official scoped edition
    • 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.

  • Fire-Resistant Plants for Home Landscapes (PNW 590) · Official scoped edition
    • ID, OR, WA; partial normalized coverage · 2023-10-01

      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.

  • Fire-Resistant Plants for Eastern Washington · Official scoped edition
    • 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 CO, CT, IA, ID, IL, IN, KY, MA, MD, ME, MI, MN, NC, NE, NH, NJ, NY, OH, OR, PA, RI, TN, VT, WA, WI, WV, WY.
Native range
No current cited or legacy state native range is normalized.
Introduced / established
No introduced or established row is normalized; that does not prove native status.
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
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.

'Fine Line® Improved' buckthorn (Rhamnus frangula)
Photo: no rights reserved (CC0), via iNaturalist. Species-typical, not necessarily this cultivar.
Form
shrub
USDA hardiness
Applicable source statements overlap but have different boundaries; compare each source
Mature height
~12 ft
Water need
moderate
Grows in
CO, CT, IA, ID, IL, IN, KY, MA +19
Rated in
British Columbia; OR/WA/ID; Ohio / Midwest; Oregon (Willamette Valley) +4
Family
Rhamnaceae
Evidence
8 cited sources

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.

Conditions in the fire evidence

These describe tested or rated plant material. They are not horticultural maintenance instructions.

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.

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.

Recommends (6)

Mid-scale / conditional (2)

Same genus in the directory · the Rhamnus group page

Last verified 2026-08-23. JSON (CC BY 4.0)

Profiles: USDA PLANTS · GBIF · iNaturalist · Wikidata · ITIS

Rhamnus frangula ('Fine Line® Improved' buckthorn). FireApproved. https://fireapproved.com/plants/rhamnus-frangula/. Last verified 2026-08-23.