Yes — Strong Match
sunflower (zones 2-11) covers every zone Alabama contains (7b-9b), so hardiness is not what limits it anywhere in the state.
Sunflower in Alabama — the short answer
Sunflower in Alabama: hardy in zones 2–11, full sun, against a state median of ~266 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
- Alabama zones
- 7b-9b
- USDA PHZM 2023
- Frost window
- Feb 24 - Mar 16 – Nov 15 - Nov 28
- NOAA RCC ACIS 1991-2020, 28°F
- Shortest county season
- 225 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 Alabama site runs ~266 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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Alabama is not one climate
A single Alabama answer averages 67 counties whose growing seasons are 72 days apart — from 225 frost-free days in Marion County to 297 in Mobile County. Which end of that your land sits nearer changes what sunflower can finish before the first hard freeze.
The middle half of 67 counties runs 244–277 days, with a median of 266 days — a 72-day span end to end.
Measured across 67 Alabama 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 Alabama Fits Best
Even within Alabama's zones 7b-9b, 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
Alabama Has
- USDA Zones: 7b-9b
- Last Hard Freeze (28°F): Feb 24 - Mar 16
- First Hard Freeze (28°F): Nov 15 - Nov 28
- Annual Rainfall: 50-65 inches
- Common Soils: Red clay, Sandy loam, Alluvial
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 Alabama
The frost window
Across Alabama, the last spring hard freeze (28°F) clears between Feb 24 and Mar 16, and the first fall hard freeze lands between Nov 15 and Nov 28 (NOAA Regional Climate Centers ACIS, 1991-2020). Counting from the latest last freeze to the earliest first freeze, that's a 244-day window you can count on — up to 277 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 Alabama's late-side last freeze of Mar 16 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 164 days to spare even in Alabama's tightest freeze scenario — room for a later start or a second sowing.
Timing tuned to sub-state frost dates — Marion County, not the statewide average.
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 Alabama site sees ~266 (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 ~5383 GDD (from PRISM 1991-2020 climate normals), so Alabama'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 Alabama's red clay and sandy loam — 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 Alabama soil test result is a problem or just a number. Drainage matters: this plant wants well (dry spells). If your Alabama 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 14.1% of Alabama as poorly or somewhat-poorly drained, and the class flips parcel to parcel. Sunflower 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 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. Alabama 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 Alabama
Zone compatibility tells you about winter cold survival — but Alabama growers also need to think about:
Heavy clay soils in the Piedmont region
High humidity promotes fungal diseases
Fire ants are a persistent garden pest
Growing sunflower here specifically
Sunflower rates to USDA zones 2–11 and takes frost damage on growing tissue around 32°F (FAO ECOCROP), but cold isn't the risk in Alabama — wet is: with roughly 14.1% of its soils poorly-drained (SSURGO), soggy ground rots the roots.
Give sunflower a raised bed or mounded row with coarse amendment so its roots never sit wet. How to handle it →
What to actually do about these — and the constraints that apply to every Alabama grower, not just sunflower — is covered on the Alabama growing guide.
Timing shifts within Alabama
Alabama isn't one climate. In Marion County, the last hard freeze (28°F) holds until about Mar 28 — roughly 26 days later than the recorded state median — so plant sunflower to your county's window, not the statewide date.
Sunflower needs about 70 days of frost-free season to complete its cycle. Even Marion County — Alabama’s shortest season at 225 frost-free days — clears that by 155 days, so season length isn’t the constraint anywhere in Alabama. What varies is your own parcel.
Across Alabama’s 67 counties the frost-free season runs from 225 days in Marion County to 297 days in Mobile County — a spread of 72 days, which is why a single statewide planting date misleads. The median Alabama county sees 266 frost-free days, leaving sunflower about 196 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 Alabama's frost window — roughly 266 days, opening after the last 28°F freeze (Feb 24 - Mar 16) and closing at the first (Nov 15 - Nov 28), per NOAA Regional Climate Centers ACIS, 1991-2020.
Recommended Sunflower Varieties for Alabama
Alabama publishes no state variety trial for sunflower, so we won't invent a "best for Alabama" list. Choose types rated to your USDA hardiness zone (7b-9b), and confirm winter survival and drainage against your own parcel.
Alabama Cooperative Extension
For Alabama-specific cultivar recommendations, planting calendars, and pest pressure for sunflower, the canonical source is Alabama Cooperative Extension System. Their fact sheets carry the local trial data we can't generalize across 50 states.
Is Sunflower native to Alabama?
Yes — the USDA PLANTS Database (accessed 2026-07-01) documents Sunflower as native to Alabama. 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 Alabama
When can I plant Sunflower in Alabama?
Alabama's last spring hard freeze (28°F) clears between Feb 24 and Mar 16, and the first fall hard freeze lands between Nov 15 and Nov 28 (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 Alabama?
Yes — Sunflower matures in 80 days (Growable Ground Plant Database), and Alabama's dependable hard-freeze-free window runs 244 days (NOAA Regional Climate Centers ACIS, 1991-2020), leaving 164 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 Alabama?
Alabama spans USDA hardiness zones 7b-9b (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 Alabama site have?
A typical Alabama site sees ~266 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. In cooler counties like Marion, the freeze-free season runs shorter than the state average, so verify your own county's window.
Is Sunflower native to Alabama?
Yes — the USDA PLANTS Database (accessed 2026-07-01) documents Sunflower as native to Alabama. Planting it supports the pollinators and wildlife that evolved alongside it.
How should I amend the soil for Sunflower in Alabama?
Sunflower prefers pH 5.5-8 and well (dry spells) drainage (FAO ECOCROP). That sits in the common-ground band across Alabama 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 Alabama?
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 Alabama
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 Alabama sunflower averages can't show:
We read public map data around Alabama — soil, climate, flood, and parcel records. How we handle your address.
25+ data sources read at your address, not the Alabama sunflower average
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
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