Conditional — Some Areas
cogon grass (zones 8-13) reaches only part of Virginia (5b-8b): zone 8 are in range, so where you are in the state decides it.
Your yard isn't the whole zone.
Virginia spans zones 5b-8b, but your yard sits in exactly one — and slope, tree cover, and cold-air pockets nudge it further. Enter your address and we'll score cogon grass against your parcel's actual hardiness, soil, and sun.
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Zone Comparison
Cogon Grass Needs
- USDA Zones: 8-13
- Frost-Free Days: 90+
- Sun: Full Sun
- Mature size: 4 ft tall
- Drought tolerance: High
Virginia Has
- USDA Zones: 5b-8b
- Last Hard Freeze (28°F): Mar 22 - Apr 2
- First Hard Freeze (28°F): Nov 2 - Nov 17
- Annual Rainfall: 36-50 inches
- Common Soils: Red clay (Piedmont), Silt loam, Sandy loam (Tidewater)
Plant Zone Range (zones 8-13)
Preferred Soil pH
Plant data: USDA PLANTS Database / Growable Ground plant catalog. State data: USDA ARS PHZM 2023, NOAA Climate Normals, NRCS SSURGO.
When to Plant Cogon Grass in Virginia
The frost window
Across Virginia, the last spring hard freeze (28°F) clears between Mar 22 and Apr 2, and the first fall hard freeze lands between Nov 2 and Nov 17 (NOAA Regional Climate Centers ACIS, 1991-2020). Counting from the latest last freeze to the earliest first freeze, that's a 214-day window you can count on — up to 240 days on a mild site in a kind year. That marks the hard freeze, not the last light frost, so tender transplants usually wait another 2-3 weeks.
Winter standing
Virginia runs as cold as USDA zone 5, and no sourced winter-hardiness floor is on record for cogon grass, so this page does not state whether it overwinters here — and gives no fall establishment date on the strength of a guess. Whether cogon grass is a permanent planting or a replant-every-spring crop for you turns on your own zone within Virginia; check its hardiness range against that before treating it as long-lived ground.
Frost window: NOAA Climate Normals 1991-2020. Plant timing fields: USDA PLANTS Database. Your site's own frost dates can run earlier or later than the state range — a parcel report pins them down.
Growing Season Fit
The zone check says cogon grass survives winter in part of Virginia, not across all of it. Whether the season is long enough — and warm enough — is a different question.
Frost-free days
Cogon Grass wants 90+ frost-free days; a typical Virginia site sees ~224 (NOAA Regional Climate Centers ACIS, 1991-2020). That leaves comfortable headroom for succession planting.
Growing degree days
Cogon Grass needs ~2000 GDD (base 50°F) to ripen. The state median runs ~3662 GDD (from PRISM 1991-2020 climate normals), so Virginia's typical season clears that easily.
GDD and chill-hour figures are computed from PRISM 1991-2020 monthly climate normals; frost-free days from NOAA Regional Climate Centers ACIS, 1991-2020. Each is the state median across its counties (P25/P75 span the within-state spread). Hardiness-zone range is USDA PHZM 2023.
Soil + Drainage Fit
Cogon Grass tolerates a wide pH range (pH 4-7.5) — 3.5 units, acid ground through alkaline — so soil acidity is rarely what limits it in Virginia. A soil test is still worth having, but for what else it tells you about this site, not to clear this plant. It will grow across that whole span, but it does best between pH 4.5 and 6 — worth knowing before you decide whether a Virginia soil test result is a problem or just a number. Drainage matters: this plant wants poorly (saturated >50% of year), well (dry spells). If your Virginia site is heavier clay or sits in a low spot, raised beds or amendment with compost solve it.
Plant pH and drainage requirements from USDA PLANTS Database. Virginia soil profile from USDA NRCS SSURGO. Site-specific verification: a 30-minute soil test from your local Extension lab.
Cogon Grass in Virginia — Quick Answer
- Verdict: Conditional — Some Areas
- Plant Zones: 8-13 (USDA PLANTS Database)
- State Zones: 5b-8b (USDA ARS PHZM 2023)
- Growing Season: 28°F hard freezes about Mar 22 - Apr 2 to Nov 2 - Nov 17 (NOAA Regional Climate Centers ACIS, 1991-2020)
- Days to Maturity: 120 days
What Else to Consider for Cogon Grass in Virginia
Zone compatibility tells you about winter cold survival — but Virginia growers also need to think about:
Heavy Piedmont red clay requires amendment
Humidity and heat in summer promote disease
Deer pressure is heavy in suburban and rural areas
What to actually do about these — and the constraints that apply to every Virginia grower, not just cogon grass — is covered on the Virginia growing guide.
Timing shifts within Virginia
Cogon Grass needs about 90 days of frost-free season to complete its cycle. Even Highland County — Virginia’s shortest season at 176 frost-free days — clears that by 86 days, so season length isn’t the constraint anywhere in Virginia. What varies is your own parcel.
Across Virginia’s 133 counties the frost-free season runs from 176 days in Highland County to 289 days in Hampton County — a spread of 113 days, which is why a single statewide planting date misleads. The median Virginia county sees 224 frost-free days, leaving cogon grass about 134 days of slack on a typical parcel — room for a second sowing where the season runs long.
County last-freeze dates and frost-free day counts: NOAA Regional Climate Centers ACIS (1991-2020), county 28°F freeze (earlier than the folk 32°F "last frost"). Cogon Grass's 90-day requirement: USDA PLANTS / Growable Ground plant database (minimum frost-free days). A parcel report resolves your address's own frost dates.
Where in Virginia Fits Best
Even within Virginia's zones 5b-8b, county microclimates differ enough to change what thrives. These counties carry the closest zone match for cogon grass (USDA PHZM 2023):
Virginia Cooperative Extension
For Virginia-specific cultivar recommendations, planting calendars, and pest pressure for cogon grass, the canonical source is Virginia Cooperative Extension. Their fact sheets carry the local trial data we can't generalize across 50 states.
Is Cogon Grass native to Virginia?
No — the USDA PLANTS Database lists Cogon Grass as introduced rather than native in the Lower 48, so it is not part of Virginia's native flora. It grows here as a garden plant; pairing it with a few Virginia natives keeps local pollinators fed too.
Looking for plants that belong here? The Virginia growing guide lists USDA-documented natives for the state.
Native-range data: USDA PLANTS Database state-distribution records, accessed 2026-07-01.
Common Questions About Growing Cogon Grass in Virginia
When can I plant Cogon Grass in Virginia?
Virginia's last spring hard freeze (28°F) clears between Mar 22 and Apr 2, and the first fall hard freeze lands between Nov 2 and Nov 17 (NOAA Regional Climate Centers ACIS, 1991-2020). No sourced winter-hardiness floor is on record for Cogon Grass, so this page does not state whether it overwinters in Virginia and publishes no fall establishment date for it — check its hardiness range against your own zone before treating it as a permanent planting.
What hardiness zone is Cogon Grass grown in across Virginia?
Virginia spans USDA hardiness zones 5b-8b (USDA ARS PHZM 2023). Cogon Grass carries a range of zones 8-13, so the overlap zones are where outdoor growing is most reliable.
How many frost-free days does a typical Virginia site have?
A typical Virginia site sees ~224 frost-free days per year (derived from NOAA Regional Climate Centers ACIS, 1991-2020). Cogon Grass needs 90+ frost-free days, so check whether your local microclimate runs above or below the state average before settling on a planting date.
Is Cogon Grass native to Virginia?
No — the USDA PLANTS Database lists Cogon Grass as introduced rather than native in the Lower 48, so it is not part of Virginia's native flora. It grows here as a garden plant; pairing it with a few Virginia natives keeps local pollinators fed too.
How should I amend the soil for Cogon Grass in Virginia?
Cogon Grass tolerates pH 4-7.5 and poorly (saturated >50% of year), well (dry spells) drainage (FAO ECOCROP). That is a 3.5-unit span, acid ground through alkaline, so pH is rarely what limits this plant on a Virginia site — amend for drainage and organic matter first.
Will Cogon Grass actually grow on my specific land in Virginia?
State-level zone + climate data is a sketch. A Growable Ground parcel report scores cogon grass against your address's exact soil pH, drainage, sun, and frost-date data drawn from USDA SSURGO, NOAA, and PRISM — not state averages.
Check your specific parcel in Virginia
State-level data is a sketch. Your Growable Ground report scores cogon grass against your parcel's exact soil, sun, drainage, and frost data — not zone averages.
Three things about your lot that Virginia cogon grass averages can't show:
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