Unlikely — Zone Mismatch
Surinam grass (zones 10-13) does not overlap with North Carolina's zone range (6a-9a). Growing outdoors is unlikely without significant protection.
2 zones short — what would close it
Surinam Grass is hardy to zone 10, and the warmest ground in North Carolina is zone 8 — 2 zones short. Planted in open ground it will not survive a North Carolina winter. To grow it here, grow surinam grass under glass — a greenhouse is the only lift this wide the engine models.
A greenhouse is the lift this needs. How a greenhouse changes what you can grow →
Zone math from 10-13 (plant) against 6-8 (North Carolina). Lift modeled by crop_engine Sprint 20B effective_zone_modifier (+2 zones) via api/fast_sections.py Unlock Engine v2.
Your yard isn't the whole zone.
North Carolina spans zones 6a-9a, but your yard has its own microclimate — slope, trees, and low spots shift frost and sun across a single parcel. Enter your address and we'll score surinam grass against your land's actual soil, sun, and frost.
We read public map data for this spot — soil, climate, flood, and parcel records. How we handle your address.
No card required · your full report in seconds
Zone Comparison
Surinam Grass Needs
- USDA Zones: 10-13
- Frost-Free Days: 90+
- Sun: Full Sun
- Mature size: 2 ft tall
- Drought tolerance: Medium
North Carolina Has
- USDA Zones: 6a-9a
- Last Hard Freeze (28°F): Mar 11 - Mar 24
- First Hard Freeze (28°F): Nov 10 - Nov 25
- Annual Rainfall: 40-60 inches
- Common Soils: Red clay (Piedmont), Sandy loam (Coastal), Mountain loam
Plant Zone Range (zones 10-13)
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 Surinam Grass in North Carolina
The frost window
Across North Carolina, the last spring hard freeze (28°F) clears between Mar 11 and Mar 24, and the first fall hard freeze lands between Nov 10 and Nov 25 (NOAA Regional Climate Centers ACIS, 1991-2020). Counting from the latest last freeze to the earliest first freeze, that's a 231-day window you can count on — up to 259 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.
Frost tenderness
Surinam Grass is frost-tender — its listed minimum temperature is 66.2°F (USDA PLANTS Database) — so set plants out two to three weeks PAST your local last hard freeze, not on it and not on the state's earliest date. The 28°F marker above is when killing freezes stop, not when light frost does.
When to start the seed
Surinam Grass is direct-sown where it grows rather than started under cover, so there is no seed-tray head start to bank — North Carolina's dates above are the whole calendar for it. That makes the last-freeze date the binding constraint, and a warmer pocket of your own yard is worth more to this crop than it is to a transplanted one.
Days to maturity vs. the window
At 90 days to maturity (USDA PLANTS Database), counting from the last hard freeze it ripens with 141 days to spare even in North Carolina's tightest freeze scenario — room for a later start or a second sowing.
Timing tuned to sub-state frost dates — Swain County, not the statewide average.
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 surinam grass does not survive a North Carolina winter in the ground. The season figures below measure a different question — whether it could finish a season here at all — and they only bear on North Carolina under protection.
Frost-free days
Surinam Grass wants 90+ frost-free days; a typical North Carolina site sees ~245 (NOAA Regional Climate Centers ACIS, 1991-2020). That leaves comfortable headroom for succession planting.
Growing degree days
Surinam Grass needs ~3000 GDD (base 50°F) to ripen. The state median runs ~4537 GDD (from PRISM 1991-2020 climate normals), so North Carolina'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
Surinam Grass likes near-neutral soil (pH 4.5-6.5). That's the common-ground band across North Carolina's red clay (piedmont) and sandy loam (coastal) — a soil test confirms it for your site. It will grow across that whole span, but it does best between pH 5 and 6 — worth knowing before you decide whether a North Carolina soil test result is a problem or just a number. Drainage matters: this plant wants well (dry spells). If your North Carolina site is heavier clay or sits in a low spot, raised beds or amendment with compost solve it.
Your land, not the state average
SSURGO maps about 14.7% of North Carolina as poorly or somewhat-poorly drained, and the class flips parcel to parcel. Surinam Grass sits mid-range for drought tolerance, so either extreme can cost you — your soil map unit, not the state average, is the real answer.
Check your parcel → Source: USDA NRCS SSURGO.
Plant pH and drainage requirements from USDA PLANTS Database. North Carolina soil profile from USDA NRCS SSURGO. Site-specific verification: a 30-minute soil test from your local Extension lab.
Surinam Grass in North Carolina — Quick Answer
- Verdict: Unlikely — Zone Mismatch
- Plant Zones: 10-13 (USDA PLANTS Database)
- State Zones: 6a-9a (USDA ARS PHZM 2023)
- Growing Season: 28°F hard freezes about Mar 11 - Mar 24 to Nov 10 - Nov 25 (NOAA Regional Climate Centers ACIS, 1991-2020)
- Days to Maturity: 90 days
What Else to Consider for Surinam Grass in North Carolina
Zone compatibility tells you about winter cold survival — but North Carolina growers also need to think about:
Red Piedmont clay is hard to work and drains poorly
Humidity drives significant disease pressure
Hurricane risk on the coastal plain
Growing surinam grass here specifically
Surinam Grass needs sharp drainage and sends shallow roots hardy to about 66°F; in North Carolina, about 14.7% of soils are poorly-drained (SSURGO), and standing water is what actually kills it.
Build surinam grass up on a coarse, free-draining mound so its roots never sit in saturated soil. How to handle it →
What to actually do about these — and the constraints that apply to every North Carolina grower, not just surinam grass — is covered on the North Carolina growing guide.
Timing shifts within North Carolina
North Carolina isn't one climate. In Swain County, the last hard freeze (28°F) holds until about Apr 27 — roughly 41 days later than the recorded state median — so plant surinam grass to your county's window, not the statewide date.
Surinam Grass needs about 90 days of frost-free season to complete its cycle. Even Swain County — North Carolina’s shortest season at 178 frost-free days — clears that by 88 days, so season length isn’t the constraint anywhere in North Carolina. What varies is your own parcel.
Across North Carolina’s 100 counties the frost-free season runs from 178 days in Swain County to 303 days in Dare County — a spread of 125 days, which is why a single statewide planting date misleads. The median North Carolina county sees 245 frost-free days, leaving surinam grass about 155 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"). Surinam 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.
North Carolina Cooperative Extension
For North Carolina-specific cultivar recommendations, planting calendars, and pest pressure for surinam grass, the canonical source is NC State Extension. Their fact sheets carry the local trial data we can't generalize across 50 states.
Common Questions About Growing Surinam Grass in North Carolina
When can I plant Surinam Grass in North Carolina?
North Carolina's last spring hard freeze (28°F) clears between Mar 11 and Mar 24, and the first fall hard freeze lands between Nov 10 and Nov 25 (NOAA Regional Climate Centers ACIS, 1991-2020). Surinam Grass is frost-tender — its listed minimum temperature is 66.2°F (USDA PLANTS Database) — so wait two to three weeks past your site's last hard freeze, when light frost has also stopped, before planting out.
Can Surinam Grass mature before first frost in North Carolina?
Yes — Surinam Grass matures in 90 days (USDA PLANTS Database), and North Carolina's dependable hard-freeze-free window runs 231 days (NOAA Regional Climate Centers ACIS, 1991-2020), leaving 141 days of margin. Plant once the last hard freeze has passed — two to three weeks later for anything tender — and it ripens ahead of the first fall freeze.
What hardiness zone is Surinam Grass grown in across North Carolina?
North Carolina spans USDA hardiness zones 6a-9a (USDA ARS PHZM 2023). Surinam Grass carries a range of zones 10-13, so the overlap zones are where outdoor growing is most reliable.
How many frost-free days does a typical North Carolina site have?
A typical North Carolina site sees ~245 frost-free days per year (derived from NOAA Regional Climate Centers ACIS, 1991-2020). Surinam 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. In cooler counties like Swain, the freeze-free season runs shorter than the state average, so verify your own county's window.
How should I amend the soil for Surinam Grass in North Carolina?
Surinam Grass prefers pH 4.5-6.5 and well (dry spells) drainage (FAO ECOCROP). That sits in the common-ground band across North Carolina soils — a 30-minute soil test from a local Extension lab confirms it for your specific site.
Will Surinam Grass actually grow on my specific land in North Carolina?
State-level zone + climate data is a sketch. A Growable Ground parcel report scores surinam 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 North Carolina
State-level data is a sketch. Your Growable Ground report scores surinam grass against your parcel's exact soil, sun, drainage, and frost data — not zone averages.
Three things about your lot that North Carolina surinam grass averages can't show:
We read public map data around North Carolina — soil, climate, flood, and parcel records. How we handle your address.
25+ data sources read at your address, not the North Carolina surinam grass average
Explore More
Growing guides for surinam grass
Analysis by the Growable Ground research team, grounded in USDA PLANTS, USDA NRCS SSURGO, NOAA Climate Normals (1991-2020), and named Cooperative Extension sources. How we know →
Cite this dataset
Kirchick, M. (2026). Growable Ground Plant Database [Data set]. Zenodo. https://doi.org/10.5281/zenodo.21435643
Licensed CC BY-NC 4.0. DOI 10.5281/zenodo.21435643
Last updated: