Yes — Strong Match
sunflower (zones 2-11) covers every zone Louisiana contains (8b-10b), so hardiness is not what limits it anywhere in the state.
Sunflower in Louisiana — the short answer
Sunflower in Louisiana: hardy in zones 2–11, full sun, against a state median of ~298 frost-free days.
- Plant zones
- 2-11
- 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
- Louisiana zones
- 8b-10b
- USDA PHZM 2023
- Frost window
- Jan 30 - Feb 17 – Nov 30 - Dec 8
- NOAA RCC ACIS 1991-2020, 28°F
- Shortest county season
- 265 days
- NOAA Regional Climate Centers ACIS, 1991-2020, county 28°F killing freeze
- Days to maturity
- 80 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.
Sunflower is grown as an annual, so your winter zone isn't the deciding factor — your frost-free window is. A typical Louisiana site runs ~298 frost-free days, but that is a state median, not your yard: slope, trees, and low spots move the last-frost date across a single parcel. Enter your address and we'll score sunflower against your land's actual frost dates, sun, and soil.
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Louisiana is not one climate
A single Louisiana answer averages 64 counties whose growing seasons are 100 days apart — from 265 frost-free days in Claiborne County to 365 in Plaquemines County. Which end of that your land sits nearer changes what sunflower can finish before the first hard freeze.
The middle half of 64 counties runs 285–313 days, with a median of 298 days — a 100-day span end to end.
Measured across 64 Louisiana 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 Louisiana Fits Best
Even within Louisiana's zones 8b-10b, county microclimates differ enough to change what thrives. These counties carry the closest zone match for sunflower (USDA PHZM 2023):
Zone Comparison
Sunflower Needs
- USDA Zones: 2-11
- Frost-Free Days: 70+
- Sun: Full Sun
- Mature size: 8 ft tall
- Picking window: ~14 days of harvest
- Drought tolerance: Medium
Louisiana Has
- USDA Zones: 8b-10b
- Last Hard Freeze (28°F): Jan 30 - Feb 17
- First Hard Freeze (28°F): Nov 30 - Dec 8
- Annual Rainfall: 50-65 inches
- Common Soils: Alluvial clay, Muck, Sandy loam
Plant Zone Range (zones 2-11)
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 Sunflower in Louisiana
The frost window
Across Louisiana, the last spring hard freeze (28°F) clears between Jan 30 and Feb 17, and the first fall hard freeze lands between Nov 30 and Dec 8 (NOAA Regional Climate Centers ACIS, 1991-2020). Counting from the latest last freeze to the earliest first freeze, that's a 286-day window you can count on — up to 312 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
Sunflower is frost-tender — FAO ECOCROP puts its killing temperature at 32°F — 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. That is the point where cold damages growing tissue, not a winter-survival floor — an established perennial comes through far colder while dormant, which is what its hardiness zone tells you.
When to start the seed
Those dates are when sunflower goes out, not when it starts. It is sown under cover about 3 weeks ahead, so counting back from Louisiana's late-side last freeze of Feb 17 is what fixes your sowing date — and a yard that clears frost earlier than the state's late date starts earlier still.
Days to maturity vs. the window
At 80 days to maturity (Growable Ground Plant Database), counting from the last hard freeze it ripens with 206 days to spare even in Louisiana'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 sunflower survives winter here. Whether the season is long enough — and warm enough — is a different question.
Frost-free days
Sunflower wants 70+ frost-free days; a typical Louisiana site sees ~298 (NOAA Regional Climate Centers ACIS, 1991-2020). That leaves comfortable headroom for succession planting.
Growing degree days
Sunflower needs ~1500 GDD (base 50°F) to ripen. The state median runs ~6204 GDD (from PRISM 1991-2020 climate normals), so Louisiana'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
Sunflower likes near-neutral soil (pH 5.5-8). That's the common-ground band across Louisiana's alluvial clay and muck — a soil test confirms it for your site. It will grow across that whole span, but it does best between pH 6 and 7.5 — worth knowing before you decide whether a Louisiana soil test result is a problem or just a number. Drainage matters: this plant wants well (dry spells). If your Louisiana 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. Louisiana soil profile from USDA NRCS SSURGO. Site-specific verification: a 30-minute soil test from your local Extension lab.
What Else to Consider for Sunflower in Louisiana
Zone compatibility tells you about winter cold survival — but Louisiana growers also need to think about:
Extreme humidity and rainfall promote rot and fungal diseases
Poor drainage in delta and coastal areas
Hurricane damage risk from June through November
What to actually do about these — and the constraints that apply to every Louisiana grower, not just sunflower — is covered on the Louisiana growing guide.
Timing shifts within Louisiana
Sunflower needs about 70 days of frost-free season to complete its cycle. Even Claiborne County — Louisiana’s shortest season at 265 frost-free days — clears that by 195 days, so season length isn’t the constraint anywhere in Louisiana. What varies is your own parcel.
Across Louisiana’s 64 counties the frost-free season runs from 265 days in Claiborne County to 365 days in Plaquemines County — a spread of 100 days, which is why a single statewide planting date misleads. The median Louisiana county sees 298 frost-free days, leaving sunflower about 228 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"). Sunflower's 70-day requirement: USDA PLANTS / Growable Ground plant database (minimum frost-free days). A parcel report resolves your address's own frost dates.
Pollinator + Wildlife Value
Sunflower draws honeybees, native bees, and butterflies (high value, Growable Ground Plant Database). Planting it near vegetable beds can lift fruit set on neighboring crops. Outdoors, sunflower can only work that bloom inside Louisiana's frost window — roughly 298 days, opening after the last 28°F freeze (Jan 30 - Feb 17) and closing at the first (Nov 30 - Dec 8), per NOAA Regional Climate Centers ACIS, 1991-2020.
Louisiana Cooperative Extension
For Louisiana-specific cultivar recommendations, planting calendars, and pest pressure for sunflower, the canonical source is LSU AgCenter. Their fact sheets carry the local trial data we can't generalize across 50 states.
Is Sunflower native to Louisiana?
Yes — the USDA PLANTS Database (accessed 2026-07-01) documents Sunflower as native to Louisiana. Planting it supports the pollinators and wildlife that evolved alongside it.
Native-range data: USDA PLANTS Database state-distribution records, accessed 2026-07-01.
Common Questions About Growing Sunflower in Louisiana
When can I plant Sunflower in Louisiana?
Louisiana's last spring hard freeze (28°F) clears between Jan 30 and Feb 17, and the first fall hard freeze lands between Nov 30 and Dec 8 (NOAA Regional Climate Centers ACIS, 1991-2020). Sunflower is frost-tender — its killing temperature is 32°F (FAO ECOCROP — the point where cold damages growing tissue, not a winter-survival floor) — so wait two to three weeks past your site's last hard freeze, when light frost has also stopped, before planting out.
Can Sunflower mature before first frost in Louisiana?
Yes — Sunflower matures in 80 days (Growable Ground Plant Database), and Louisiana's dependable hard-freeze-free window runs 286 days (NOAA Regional Climate Centers ACIS, 1991-2020), leaving 206 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 Sunflower grown in across Louisiana?
Louisiana spans USDA hardiness zones 8b-10b (USDA ARS PHZM 2023). Sunflower carries a range of zones 2-11, so the overlap zones are where outdoor growing is most reliable.
How many frost-free days does a typical Louisiana site have?
A typical Louisiana site sees ~298 frost-free days per year (derived from NOAA Regional Climate Centers ACIS, 1991-2020). Sunflower needs 70+ frost-free days, so check whether your local microclimate runs above or below the state average before settling on a planting date.
Is Sunflower native to Louisiana?
Yes — the USDA PLANTS Database (accessed 2026-07-01) documents Sunflower as native to Louisiana. Planting it supports the pollinators and wildlife that evolved alongside it.
How should I amend the soil for Sunflower in Louisiana?
Sunflower prefers pH 5.5-8 and well (dry spells) drainage (FAO ECOCROP). That sits in the common-ground band across Louisiana soils — a 30-minute soil test from a local Extension lab confirms it for your specific site.
Will Sunflower actually grow on my specific land in Louisiana?
State-level zone + climate data is a sketch. A Growable Ground parcel report scores sunflower 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 Louisiana
State-level data is a sketch. Your Growable Ground report scores sunflower against your parcel's exact soil, sun, drainage, and frost data — not zone averages.
Three things about your lot that Louisiana sunflower averages can't show:
We read public map data around Louisiana — soil, climate, flood, and parcel records. How we handle your address.
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