Conditional — Some Areas
Surinam grass (zones 10-13) reaches only part of Texas (6b-10b): zone 10 are in range, so where you are in the state decides it.
Surinam Grass in Texas — the short answer
Surinam Grass in Texas: hardy in zones 10–13, full sun, against a state median of ~274 frost-free days.
- Plant zones
- 10-13
- Manual horticultural correction (source not retained); NC State Extension and Missouri Botanical Garden, with the remaining rows from other published sources or Growable Ground compilation
- Texas zones
- 6b-10b
- USDA PHZM 2023
- Frost window
- Feb 10 - Mar 12 – Nov 18 - Dec 4
- NOAA RCC ACIS 1991-2020, 28°F
- Shortest county season
- 197 days
- NOAA Regional Climate Centers ACIS, 1991-2020, county 28°F killing freeze
- Days to maturity
- 90 days
- Growable Ground Plant Database
Plant data: Growable Ground Plant Database, compiled from FAO ECOCROP, USDA PLANTS and university Extension sources — per-field provenance varies and is published with the dataset.
Your yard isn't the whole zone.
Texas spans zones 6b-10b, 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.
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Texas is not one climate
A single Texas answer averages 254 counties whose growing seasons are 146 days apart — from 197 frost-free days in Dallam County to 343 in Kenedy County. Which end of that your land sits nearer changes what surinam grass can finish before the first hard freeze.
The middle half of 254 counties runs 252–297 days, with a median of 274 days — a 146-day span end to end.
Measured across 254 Texas counties. NOAA Regional Climate Centers ACIS, 1991-2020, county 28°F killing freeze. Quartiles are order statistics — every figure shown is a value a real county recorded, not an interpolation. Your own site sits somewhere inside this range; a parcel report resolves where.
Where in Texas Fits Best
Surinam Grass is rated for zones 10–13 — a cold floor USDA puts at 30 to 40°F. Against Texas’s 254 counties that band holds in 5 of them, and the line runs at Cameron County (zone 10a), the coldest county still inside it.
Below the zone 10 floor
249 counties
- Dallam County · zone 6b
- Lipscomb County · zone 6b
- Armstrong County · zone 7a
3 of 249 shown
Winter cold is the limit here — the same plant works in a container that comes under cover.
County hardiness zones: USDA Plant Hardiness Zone Map (PHZM) 2023, per county. A zone is a 10°F band of average annual extreme minimum temperature, so the floor above is the band the plant's rating denotes, not a single measured kill point. Slope, shelter and cold-air drainage routinely move a site half a zone either way from its county figure — which is the part only your address resolves.
Even within Texas's zones 6b-10b, county microclimates differ enough to change what thrives. These counties carry the closest zone match for surinam grass (USDA PHZM 2023):
Zone Comparison
Surinam Grass Needs
- USDA Zones: 10-13
- Frost-Free Days: 90+
- Sun: Full Sun
- Mature size: 2 ft tall
- Drought tolerance: Medium
Texas Has
- USDA Zones: 6b-10b
- Last Hard Freeze (28°F): Feb 10 - Mar 12
- First Hard Freeze (28°F): Nov 18 - Dec 4
- Annual Rainfall: 8-56 inches
- Common Soils: Black clay (Blackland Prairie), Sandy loam, Caliche
Plant Zone Range (zones 10-13)
Preferred Soil pH
Plant data: Growable Ground Plant Database, compiled from FAO ECOCROP, USDA PLANTS, and university Extension sources — per-field provenance varies and is published with the dataset. State data: USDA ARS PHZM 2023, NOAA Climate Normals, NRCS SSURGO.
When to Plant Surinam Grass in Texas
The frost window
Across Texas, the last spring hard freeze (28°F) clears between Feb 10 and Mar 12, and the first fall hard freeze lands between Nov 18 and Dec 4 (NOAA Regional Climate Centers ACIS, 1991-2020). Counting from the latest last freeze to the earliest first freeze, that's a 251-day window you can count on — up to 297 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.
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 — Texas'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 (Growable Ground Plant Database), counting from the last hard freeze it ripens with 161 days to spare even in Texas's tightest freeze scenario — room for a later start or a second sowing.
Frost window: NOAA Climate Normals 1991-2020. Plant timing fields: Growable Ground Plant Database — frost-free days from FAO ECOCROP, days to harvest from university Extension production guides, and growing-degree-day and chill-hour minimums that are compilation estimates rather than published figures. 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 survives winter in part of Texas, not across all of it. Whether the season is long enough — and warm enough — is a different question.
Frost-free days
Surinam Grass wants 90+ frost-free days; a typical Texas site sees ~274 (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 ~5834 GDD (from PRISM 1991-2020 climate normals), so Texas'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 Texas's black clay (blackland prairie) and sandy loam — 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 Texas soil test result is a problem or just a number. Drainage matters: this plant wants well (dry spells). If your Texas site is heavier clay or sits in a low spot, raised beds or amendment with compost solve it.
Plant pH requirements: FAO ECOCROP and USDA PLANTS, with the remaining rows from other published sources or Growable Ground compilation. Drainage: FAO ECOCROP, with the remaining rows from other published sources or Growable Ground compilation. Texas soil profile from USDA NRCS SSURGO. Site-specific verification: a 30-minute soil test from your local Extension lab.
What Else to Consider for Surinam Grass in Texas
Zone compatibility tells you about winter cold survival — but Texas growers also need to think about:
Extreme heat (100F+ days) stresses many crops from June through September
Rainfall varies dramatically — 8 inches in west TX to 56 inches in east TX
Heavy black clay (Blackland Prairie) is difficult to work and drains poorly
Flash drought conditions can develop rapidly even in wet years
What to actually do about these — and the constraints that apply to every Texas grower, not just surinam grass — is covered on the Texas growing guide.
Timing shifts within Texas
Surinam Grass needs about 90 days of frost-free season to complete its cycle. Even Dallam County — Texas’s shortest season at 197 frost-free days — clears that by 107 days, so season length isn’t the constraint anywhere in Texas. What varies is your own parcel.
Across Texas’s 254 counties the frost-free season runs from 197 days in Dallam County to 343 days in Kenedy County — a spread of 146 days, which is why a single statewide planting date misleads. The median Texas county sees 274 frost-free days, leaving surinam grass about 184 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.
Texas Cooperative Extension
For Texas-specific cultivar recommendations, planting calendars, and pest pressure for surinam grass, the canonical source is Texas A&M AgriLife Extension Service. Their fact sheets carry the local trial data we can't generalize across 50 states.
Common Questions About Growing Surinam Grass in Texas
When can I plant Surinam Grass in Texas?
Texas's last spring hard freeze (28°F) clears between Feb 10 and Mar 12, and the first fall hard freeze lands between Nov 18 and Dec 4 (NOAA Regional Climate Centers ACIS, 1991-2020). Time outdoor planting to after the last hard freeze for your specific site — a further two to three weeks for anything tender — and count back from those dates for transplant scheduling.
Can Surinam Grass mature before first frost in Texas?
Yes — Surinam Grass matures in 90 days (Growable Ground Plant Database), and Texas's dependable hard-freeze-free window runs 251 days (NOAA Regional Climate Centers ACIS, 1991-2020), leaving 161 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 Texas?
Texas spans USDA hardiness zones 6b-10b (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 Texas site have?
A typical Texas site sees ~274 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.
How should I amend the soil for Surinam Grass in Texas?
Surinam Grass prefers pH 4.5-6.5 and well (dry spells) drainage (FAO ECOCROP). That sits in the common-ground band across Texas 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 Texas?
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 Texas
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 Texas surinam grass averages can't show:
We read public map data around Texas — soil, climate, flood, and parcel records. How we handle your address.
25+ data sources read at your address, not the Texas surinam grass average
Explore More
Growing guides for surinam grass
Explore Texas county by county
Texas carries 254 counties with their own USDA zone — a sample of the growing pages for surinam grass there:
Where else surinam grass grows
Surinam Grass's zone band crosses state lines — these are the states closest to Texas in winter climate where it also has a page, plus the far ends of its range. Each one re-answers the question with that state's own record.
More to grow in Texas
Texas has a growing page for 1,041 plants — a rotating sample of the rest of the shelf.
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