cork oak

Quercus suber · Fagaceae · all Quercus records · Wikipedia

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Cork oak is highly flammable; a gardening guide’s recommendation does not overturn the warning to keep it away from structures.

Three of four sources that reach a verdict warn against cork oak. INRA’s Avignon tests gave it note 4 of 5 at the July-to-September maximum. A 2017 study in Landscape and Urban Planning called it extremely flammable after testing 200 live-leaf samples, which averaged 7.48 seconds to ignition and 13.96 seconds of flame. The European Scientific Journal likewise placed fresh material in its note 3 high-flammability class.

Girona’s provincial government and Catalonia’s fire service provide the dissenting judgment, rating cork oak “recommended.” Species-specific care is a condition of that recommendation. To judge garden suitability, the guide considers maintenance, fuel structure, origin, and invasiveness alongside fire research and fire-service experience. This is broader than measuring ignition alone, but the different methods do not establish why the judgments conflict.

Two other measurements leave that conflict unsettled. Tests of fresh and oven-dried shoots produced condition-dependent clusters without assigning cork oak a single class. A separate calorimeter observation found that live outer bark tested without drying took 89 seconds to begin flaming, but that value concerns one plant part under one test setup. For siting near a structure, the repeated high-flammability results carry more weight than the lone gardening recommendation.

Fire-resistant trees instead

Form: tree
Rated in: Catalonia, Spain; Córdoba, southern Spain; Global; Mediterranean France / Provence +2

On this lot

1. Fire evidence and conditions

Fire evidence: Highly flammable — location does not change the cited classification.
Fire-performance conditions: 1 condition stated in cited fire-evidence rows.
Fire ecology context
Placement evidence: 2 source placement records; source schemes remain separate.
Evidence regions: Catalonia, Spain; Córdoba, southern Spain; Global; Mediterranean France / Provence; Tlemcen Mountains, western Algeria; Tlemcen, western Algeria
Maintenance

2. Why this plant is relevant here

State distribution: Documented in HI, LA.
Native range
Introduced / established
USDA hardiness

3. Legal, ecological, and broader status

Legal-list status
Seed-list status
Reported invasive here: 2 ecological invasive reports.
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.

Conditions in the fire evidence

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

green: The ignition index based on flammability of vegetation improves planning in the WUI evidence row, The fire risk of the plant groupings with Cistus in the area of Tlemcen (Western Algeria) evidence row

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.

Guía de pirojardinería: suitable inside or outside the 25-metre maximum-risk zone [girona-2020-iuf-25m-suitability] (with its recommendation)
The fire risk of the plant groupings with Cistus in the a…: Table 1 [henaoui-2013-fresh-material-flammability] (with its avoid rating)

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.

Avoids (3)

Inflammabilités des espèces forestières méditerranéennes (Valette 1990) — INRA Station de Sylviculture méditerranéenne, Avignon (Revue Forestière Française XLII) · 1990 · original source Primary evidence Lab-tested lineage: inra-tree

“INRA inflammability note 4 of 5 (July-September maximum)” · score 4 (inra-0-5)

Monthly inflammability notes May-April: 0, 2, 4, 4, 3, 4, 4, 4, 4, 4, 4, 5 (epiradiator tests, INRA Avignon).

Source wording: “hautement inflammable”
The ignition index based on flammability of vegetation improves planning in the WUI — Landscape and Urban Planning (Molina, Martín, Rodríguez y Silva & Herrera) · 2017 · original source Primary evidence Lab-tested lineage: molina-uco-tree

“Extremely flammable (Valette 5)” · score 5 (valette-0-5-live-leaf) · condition: green

Table 2 reports 87.14% foliar moisture, 7.48 s mean time to ignition, and 13.96 s mean flame duration across 200 live-leaf samples.
The fire risk of the plant groupings with Cistus in the area of Tlemcen (Western Algeria) — European Scientific Journal · European Scientific Journal 9(29) · original source Primary evidence Lab-tested lineage: valette-1990

“High flammability — note 3” · score 3 (henaoui-2013-flammability-note-1-3) · condition: green · original source

Table 1 classifies Quercus suber at flammability note 3; the paper prints its stratum as Tree.

Mid-scale / conditional (1)

Flammability of some companion species in cork oak forests — Annals of Forest Science (Dehane, Hernando, Guijarro & Madrigal) · 2017 · original source Primary evidence Lab-tested lineage: inia-madrid-tree

“Measured in condition-dependent clusters; no overall directional class”

Fresh and oven-dried shoot flammability was measured; condition-dependent cluster changes were not collapsed into a low verdict.

Listed without a rating (86)

Corroboration (86 rows from 1 source)

FLAMITS: FLAMmability plant traiTS database — Dryad / Global Ecology and Biogeography · Dryad version 9 · original source Corroboration Trait database lineage: meta-aggregator

86 cited rows from this source; its identity, lineage and tier are stated once.
- Primary study Benhalima2020: Benhalima, Y., & Dehane, B. (2020). Characterization of flammability parameters of cork by the mass loss calorimeter technique. IOBC-WPRS Bulletin, 152, 22-25.
  
  Shared row context: plant part outer bark; fuel live; predrying no; device calorimeter; site Benhalima2020-1; sampling ND.
  - “time to flaming (s): 89”
    
    FLAMITS record 657; Ignitability measurement.
  - “flaming duration (s): 2006”
    
    FLAMITS record 658; Sustainability measurement.
  - Shared measurement context: Combustibility measurement.
    - “maximum energy flux (kW/m²): 208”
      
      FLAMITS record 659.
    - “calorific value (kcal/kg): 6742.35”
      
      FLAMITS record 660.
    - “mass loss rate (g/s): 0.02”
      
      FLAMITS record 661.
  - “burnt biomass (%): 66”
    
    FLAMITS record 662; Consumability measurement.
- Primary study Dehane2015: Dehane, B., Madrigal, J., Hernando, C., Bouhraoua, R., & Guijarro, M. (2015). New bench-scale protocols for characterizing bark flammability and fire resistance in trees: application to Algerian cork. Journal of Fire Sciences, 33, 202-217.
  
  Shared row context: plant part outer bark; fuel dead; predrying no; device calorimeter; site Dehane2015-1; sampling ND.
  - “time to flaming (s): 89”
    
    FLAMITS record 2284; Ignitability measurement.
  - “flaming duration (s): 2006”
    
    FLAMITS record 2285; Sustainability measurement.
  - Shared measurement context: Combustibility measurement.
    - “energy flux (kW/m²): 65”
      
      FLAMITS record 2286.
    - “mass loss rate (g/s): 0.02”
      
      FLAMITS record 2287.
    - “maximum energy flux (kW/m²): 208”
      
      FLAMITS record 2289.
  - “burnt biomass (%): 66”
    
    FLAMITS record 2288; Consumability measurement.
- Primary study Dehane2017: Dehane, B., Hernando, C., Guijarro, M., & Madrigal, J. (2017). Flammability of some companion species in cork oak (Quercus suber L.) forests. Annals of Forest Science, 74, 60.
  
  Shared row context: plant part leaves; fuel live; device calorimeter; site Dehane2017-1; sampling september.
  - “time to flaming (s): 6.7”
    
    FLAMITS record 2297; Ignitability measurement; predrying yes.
  - Shared measurement context: Combustibility measurement; predrying yes.
    - “calorific value (kcal/kg): 3045.28”
      
      FLAMITS record 2307.
    - “maximum energy flux (kW/m²): 251.12”
      
      FLAMITS record 2317.
  - “burnt biomass (%): 94”
    
    FLAMITS record 2327; Consumability measurement; predrying yes.
  - “time to flaming (s): 27”
    
    FLAMITS record 2337; Ignitability measurement; predrying no.
  - Shared measurement context: Combustibility measurement; predrying no.
    - “calorific value (kcal/kg): 341.07”
      
      FLAMITS record 2347.
    - “maximum energy flux (kW/m²): 102.07”
      
      FLAMITS record 2357.
  - “burnt biomass (%): 97.03”
    
    FLAMITS record 2367; Consumability measurement; predrying no.
- Primary study DeLillis2009: De Lillis, M., Bianco, P. M., & Loreto, F. (2009). The influence of leaf water content and isoprenoids on flammability of some Mediterranean woody species. International Journal of Wildland Fire, 18, 203-212.
  
  Shared row context: Ignitability measurement; plant part leaves; fuel live; predrying no; device epiradiator; site DeLillis2009-1; sampling june to september.
  - “temperature at flaming (°C): 482.39”
    
    FLAMITS record 2388.
  - “temperature at flaming (°C): 525.8”
    
    FLAMITS record 2389.
  - “temperature at flaming (°C): 515.82”
    
    FLAMITS record 2390.
  - “temperature at flaming (°C): 414.51”
    
    FLAMITS record 2391.
  - “temperature at smoke (°C): 117.7”
    
    FLAMITS record 2409.
  - “temperature at smoke (°C): 119.41”
    
    FLAMITS record 2410.
  - “temperature at smoke (°C): 111.29”
    
    FLAMITS record 2411.
  - “temperature at smoke (°C): 111.14”
    
    FLAMITS record 2412.
- Primary study Essaghi2017: Essaghi, S., Hachmi, M. H., Yessef, M., Dehhaoui, M., & El Amarty, F. (2017). Assessment of Flammability of Moroccan Forest Fuels: New Approach to Estimate the Flammability Index. Forests, 8, 443.
  
  Shared row context: Ignitability measurement; plant part twigs; fuel all; predrying no; device epiradiator; site Essaghi2017-4; sampling january.
  - “flammability value: 8.15”
    
    FLAMITS record 3315.
  - “flammability value: 14.9”
    
    FLAMITS record 3328.
- “calorific value (kcal/kg): 4922.61”
  
  FLAMITS record 3923; Combustibility measurement; plant part twigs; fuel live; predrying yes; device calorimeter; site Gillon1997-1; sampling june to september. Primary study Gillon1997: Gillon, D., Hernando, C., Valette, J.-C., & Joffre, R. (1997). Fast estimation of the calorific values of forest fuels by near infrared-reflectance spectroscopy. Canadian Journal of Forest Research, 27, 760-765.
- Primary study Hachmi2011: Hachmi, M. H., Sesbou, A., Benjelloun, H., El Handouz, N., & Bouanane, F. (2011). A Simple Technique to Estimate the Flammability Index of Moroccan Forest Fuels. Journal of Combustion, 2011, 1-11.
  
  Shared row context: plant part twigs; fuel live; predrying no; device epiradiator; site Hachmi2011-1; sampling ND.
  - Shared measurement context: Ignitability measurement.
    - “time to flaming (s): 2.4”
      
      FLAMITS record 4722.
    - “flammability value: 2.97”
      
      FLAMITS record 4789.
  - “flame height (cm): 22”
    
    FLAMITS record 4779; Combustibility measurement.
  - “burning duration (s): 13.6”
    
    FLAMITS record 4780; Sustainability measurement.
- Primary study Henaoui2013: Henaoui, S. E. -A., Bouazza, M., & Amara, M. (2013). The fire risk of the plant groupings with Cistus in the area of Tlemcen (Western Algeria). European Scientific Journal, 9, 84-103.
  
  Shared row context: plant part twigs; fuel live; predrying yes; device infrared burner; site Henaoui2013-1; sampling spring.
  - “flame height (cm): 34.48”
    
    FLAMITS record 4893; Combustibility measurement.
  - “time to flaming (s): 49.77”
    
    FLAMITS record 4931; Ignitability measurement.
  - “burning duration (s): 96.2”
    
    FLAMITS record 4969; Sustainability measurement.
- Primary study Martin1989: Martín, E., & Miguel, L. (1989). Inflamabilidad y energía de las especies de sotobosque
  
  Shared row context: plant part twigs; fuel live; predrying yes; device epiradiator; site Martin1989-1.
  - Shared measurement context: Ignitability measurement; sampling may.
    - “time to flaming (s): 32”
      
      FLAMITS record 7791.
    - “ignition frequency (%): 88”
      
      FLAMITS record 8186.
  - Shared measurement context: Ignitability measurement; sampling july.
    - “time to flaming (s): 20”
      
      FLAMITS record 7792.
    - “ignition frequency (%): 96”
      
      FLAMITS record 8187.
  - Shared measurement context: Ignitability measurement; sampling august.
    - “time to flaming (s): 26”
      
      FLAMITS record 7793.
    - “ignition frequency (%): 92”
      
      FLAMITS record 8188.
  - Shared measurement context: Ignitability measurement; sampling september.
    - “time to flaming (s): 14”
      
      FLAMITS record 7794.
    - “ignition frequency (%): 100”
      
      FLAMITS record 8189.
  - Shared measurement context: Ignitability measurement; sampling october.
    - “time to flaming (s): 17”
      
      FLAMITS record 7795.
    - “ignition frequency (%): 100”
      
      FLAMITS record 8190.
  - Shared measurement context: Ignitability measurement; sampling november.
    - “time to flaming (s): 20”
      
      FLAMITS record 7796.
    - “ignition frequency (%): 99”
      
      FLAMITS record 8191.
  - “calorific value (kcal/kg): 4887”
    
    FLAMITS record 7915; Combustibility measurement; sampling ND.
  - “flammability value: 4”
    
    FLAMITS record 7964; Ignitability measurement; sampling ND.
- Primary study Massari1998: Massari, G., & Leopaldi, A. (1998). Leaf flammability in Mediterranean species. Plant Biosystems - An International Journal Dealing with all Aspects of Plant Biology, 132, 29-38.
  
  Shared row context: plant part leaves; fuel live; predrying yes; device epiradiator; site Massari1998-1; sampling ND.
  - Shared measurement context: Ignitability measurement.
    - “time to flaming (s): 126”
      
      FLAMITS record 8968.
    - “time to smoke (s): 15”
      
      FLAMITS record 9002.
  - Shared measurement context: Combustibility measurement.
    - “maximum flame temperature (°C): 408”
      
      FLAMITS record 8985.
    - “maximum flame temperature (°C): 249”
      
      FLAMITS record 9019.
    - “maximum flame temperature (°C): 345”
      
      FLAMITS record 9051.
  - “smouldering duration (s): 82”
    
    FLAMITS record 9035; Sustainability measurement.
- Primary study Molina2017: Molina, J. R., Martín, T., Rodríguez Y Silva, F., & Herrera, M. Á. (2017). The ignition index based on flammability of vegetation improves planning in the wildland-urban interface: A case study in Southern Spain. Landscape and Urban Planning, 158, 129-138.
  
  Shared row context: plant part leaves; fuel live; predrying no; device epiradiator; site Molina2017-1; sampling summer.
  - Shared measurement context: Ignitability measurement.
    - “time to flaming (s): 7.48”
      
      FLAMITS record 9306.
    - “flammability value: 5”
      
      FLAMITS record 9342.
  - “flaming duration (s): 13.96”
    
    FLAMITS record 9324; Sustainability measurement.
- Primary study Molina2018: Molina, J. R., Prades, C., Lora, Á., & Silva, F. R. (2018). Quercus suber cork as a keystone trait for fire response: A flammability analysis using bench and field scales. Forest Ecology and Management, 429, 384-393.
  
  Shared row context: plant part outer bark; fuel dead; predrying no; device epiradiator; site Molina2018-1; sampling ND.
  - Shared measurement context: Combustibility measurement.
    - “maximum sample temperature (°C): 69.33”
      
      FLAMITS record 9344.
    - “maximum sample temperature (°C): 79”
      
      FLAMITS record 9345.
    - “maximum sample temperature (°C): 95.5”
      
      FLAMITS record 9346.
    - “maximum sample temperature (°C): 109.92”
      
      FLAMITS record 9347.
    - “maximum sample temperature (°C): 112.45”
      
      FLAMITS record 9348.
    - “maximum sample temperature (°C): 114.42”
      
      FLAMITS record 9349.
  - Shared measurement context: Consumability measurement.
    - “burnt biomass (%): 95.82”
      
      FLAMITS record 9350.
    - “burnt biomass (%): 91.79”
      
      FLAMITS record 9351.
    - “burnt biomass (%): 89.6”
      
      FLAMITS record 9352.
    - “burnt biomass (%): 84.92”
      
      FLAMITS record 9353.
    - “burnt biomass (%): 84.28”
      
      FLAMITS record 9354.
    - “burnt biomass (%): 80.47”
      
      FLAMITS record 9355.
- Primary study Valette1990: Valette, J.-C. (1990). Flammabilities of Mediterranean forest species. Effects on the combustibility of the forest communities inflammabilités des espèces forestières méditerranéennes. Conséquences sur la combustibilité des formations forestières. Revue forestière française, 42, 76-92.
  
  Shared row context: Ignitability measurement; plant part leaves; fuel live; predrying no; device epiradiator; site Valette1990-1; sampling june to september.
  - “flammability value: 3”
    
    FLAMITS record 13353.
  - “flammability value: 5”
    
    FLAMITS record 13354.
- Primary study Valette1992: Valette, J. C. (1992). Inflammabilities of Mediterranean species. In P. Balabanis, R. Eftichidir & R. Fantechi (Eds.), Forest fire risk and management: European school of climatology and natural hazard course. (pp. 51-64). Halkidiki, GR: General Directorate for Science, Research and Development of the European Commission.
  
  Shared row context: Ignitability measurement; plant part twigs; fuel live; predrying yes; device epiradiator; site Valette1992-1; sampling may to november.
  - “time to flaming (s): 14.77”
    
    FLAMITS record 13373.
  - “time to flaming (s): 12.34”
    
    FLAMITS record 13374.
  - “time to flaming (s): 6.52”
    
    FLAMITS record 13375.
  - “time to flaming (s): 4.73”
    
    FLAMITS record 13376.
  - “time to flaming (s): 3.23”
    
    FLAMITS record 13377.
  - “time to flaming (s): 2.25”
    
    FLAMITS record 13378.
- Primary study Benhalima2019: Benhalima, Y., & Dehane, B. (2019). Flammability of certain conifers and oak species of north west Algeria. Proceedings of the X International Scientific Agricultural Symposium Agrosym 2019. Jahorina.
  
  Shared row context: plant part twigs; fuel live; predrying no; device calorimeter; site Benhalima2019-1; sampling september 2017.
  - “time to flaming (s): 28.14”
    
    FLAMITS record 16773; Ignitability measurement.
  - Shared measurement context: Combustibility measurement.
    - “maximum energy flux (kW/m²): 89.88”
      
      FLAMITS record 16774.
    - “calorific value (kcal/kg): 1796.121145”
      
      FLAMITS record 16775.
  - “burnt biomass (%): 97.02”
    
    FLAMITS record 16776; Consumability measurement.
- “time to flaming (s): 61”
  
  FLAMITS record 18334; Ignitability measurement; plant part twigs; fuel live; predrying yes; device epiradiator; site Delabraze1974-1; sampling june to september 1974. Primary study Delabraze1974: Delabraze, P., & Valette, J. -C. (1974). Inflammabilitéet combustibilitéde la végétation forestière méditerranéenne. Revue Forestiere Française, 26, 171177.

Fire-resistant trees instead

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Quercus stellata

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Tilia americana

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black cherry
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Fire-resistant trees listed above

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

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

Quercus suber (Cork oak). FireApproved. https://fireapproved.com/plants/quercus-suber/. Last verified 2026-08-23.

1. Fire evidence and conditions

2. Why this plant is relevant here

3. Legal, ecological, and broader status

Conditions in the fire evidence

Where its sources say to plant it

The evidence

Recommends (1)

Avoids (3)

Mid-scale / conditional (1)

Related plants

Fire-resistant trees instead