Enter your ZIP to see whether this is legal to plant in your state, and whether it survives your winter.
Redtop has a measured heat value, but that measurement does not establish that it is fire resistant.
The FLAMITS database, published through Dryad / Global Ecology and Biogeography, reports a calorific value of 4,152.34 kilocalories per kilogram for dead stems that were dried before being burned in a calorimeter.
Calorific value measures how much heat fuel releases when burned. It does not, by itself, tell you how easily the plant catches fire or how quickly fire would spread through a planting. The preparation matters: this was a measurement of dried stem material, so it cannot be read as a test of a living grass under garden conditions. FLAMITS preserves those experimental details and does not apply a common threshold that turns unlike measurements into a resistant or flammable rating.
Redtop, Agrostis gigantea, is a grass in the Poaceae family with high water needs and hardiness to USDA zone 3a. At maturity, it reaches about two feet. Those traits describe its growing needs and size; they do not settle its response to fire. For a homeowner choosing vegetation, the calorimeter result is useful information about the fuel, but insufficient grounds to choose redtop for fire resistance.
Form
grass
Mature height
~2 ft
Water need
high
Rated in
Global
On this lot
1. Fire evidence and conditions
Fire evidence
Mixed evidence — location does not change the cited classification.
Fire-performance conditions
Fire ecology context
Placement evidence
Evidence regions
Global
Maintenance
2. Why this plant is relevant here
State distribution
Documented in AK, AL, AR, AZ, CA, CO, CT, DC, DE, GA, IA, ID, IL, IN, KS, KY, LA, MA, MD, ME, MI, MN, MO, MS, MT, ND, NE, NH, NJ, NM, NV, NY, OH, OK, OR, PA, RI, SC, TN, TX, UT, VA, VT, WA, WI, WV, WY.
Native range
Introduced / established
48 sourced range or established records. This is not an invasive warning.
USDA hardiness
Documented minimum 3a; no upper limit is documented.
3. Legal, ecological, and broader status
Legal-list status
Seed-list status
Reported invasive here
1 ecological invasive report.
Broader regional context
Federal context
Plant-specific state seed-list reviews (4)
These source-bound receipts answer only the July 2026 state noxious-weed seed-list question.
This answers only whether the plant identity appears in the July 2026 state noxious-weed seed sheet. It does not establish non-seed plant legal status, ecological-invasive status, nursery-sale rules, or unrestricted use.
NH · Seed-list name scope unresolved. An exact source taxon is governed by “Undesirable Grass Seeds” or an applicable source note, so the qualified row is held instead of publishing an unconditional result. Held source row: usda-ams-state-noxious-weed-seed-2026:NH:038. Governing seed section: Undesirable Grass Seeds; normalized seed-kind scope: lawn and turf seed; applicable note rows usda-ams-state-noxious-weed-seed-2026:NH:029, usda-ams-state-noxious-weed-seed-2026:NH:041, usda-ams-state-noxious-weed-seed-2026:NH:043, usda-ams-state-noxious-weed-seed-2026:NH:045.Official USDA seed requirements.Normalized source record.
PA · Seed-list name scope unresolved. An exact source taxon is governed by “Restricted (Undesirable Grass Seeds) in lawn and turf seeds” or an applicable source note, so the qualified row is held instead of publishing an unconditional result. Held source row: usda-ams-state-noxious-weed-seed-2026:PA:050. Governing seed section: Restricted (Undesirable Grass Seeds) in lawn and turf seeds; normalized seed-kind scope: lawn and turf seed; applicable note rows usda-ams-state-noxious-weed-seed-2026:PA:053, usda-ams-state-noxious-weed-seed-2026:PA:054, usda-ams-state-noxious-weed-seed-2026:PA:055.Official USDA seed requirements.Normalized source record.
VA · Seed-list name scope unresolved. An exact source taxon is governed by “Restricted - Lawn and turf seed only” or an applicable source note, so the qualified row is held instead of publishing an unconditional result. Held source row: usda-ams-state-noxious-weed-seed-2026:VA:037. Governing seed section: Restricted - Lawn and turf seed only; normalized seed-kind scope: lawn and turf seed; applicable note rows usda-ams-state-noxious-weed-seed-2026:VA:014, usda-ams-state-noxious-weed-seed-2026:VA:040, usda-ams-state-noxious-weed-seed-2026:VA:041.Official USDA seed requirements.Normalized source record.
WV · Seed-list name scope unresolved. An exact source taxon is governed by “Restricted Noxious-weed Seed in Lawn and Turf Seed and Mixture” or an applicable source note, so the qualified row is held instead of publishing an unconditional result. Held source row: usda-ams-state-noxious-weed-seed-2026:WV:070. Governing seed section: Restricted Noxious-weed Seed in Lawn and Turf Seed and Mixture; normalized seed-kind scope: lawn and turf seed; applicable note rows usda-ams-state-noxious-weed-seed-2026:WV:079, usda-ams-state-noxious-weed-seed-2026:WV:080, usda-ams-state-noxious-weed-seed-2026:WV:081.Official USDA seed requirements.Normalized source record.
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 20136, Temperature, Minimum (°F).
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 without a rating (2)Corroboration (2 rows from 1 source)
2 cited rows from this source; its identity, lineage and tier are stated once.
Primary study Hogenbirk1995: Hogenbirk, J.C., & Sarrazin-Delay, C.L. (1995). Using fuel characteristics to estimate plant ignitability for fire hazard reduction. Water Air Soil Pollut, 82, 161170.
Shared row context: Combustibility measurement; plant part stems; predrying yes; device calorimeter; site Hogenbirk1995-1; sampling june.
