sunflower (Helianthus annuus), photographi

Can I Grow Sunflower in Mississippi?

USDA Zones 7b-9b · Plant zone range 2-11

Yes — Strong Match

sunflower (zones 2-11) covers every zone Mississippi contains (7b-9b), so hardiness is not what limits it anywhere in the state.

Sunflower in Mississippi — the short answer

Sunflower in Mississippi: hardy in zones 2–11, full sun, against a state median of ~273 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
Mississippi zones
7b-9b
USDA PHZM 2023
Frost window
Feb 17 - Mar 3 – Nov 21 - Nov 30
NOAA RCC ACIS 1991-2020, 28°F
Shortest county season
232 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.

Score your parcel · free

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 Mississippi site runs ~273 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.

We read public map data for this spot — soil, climate, flood, and parcel records. How we handle your address.

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Mississippi is not one climate

A single Mississippi answer averages 82 counties whose growing seasons are 77 days apart — from 232 frost-free days in Tishomingo County to 309 in Harrison County. Which end of that your land sits nearer changes what sunflower can finish before the first hard freeze.

232 daysTishomingo County309 daysHarrison County

The middle half of 82 counties runs 262286 days, with a median of 272 days — a 77-day span end to end.

Measured across 82 Mississippi 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 Mississippi Fits Best

Even within Mississippi'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

Mississippi Has

  • USDA Zones: 7b-9b
  • Last Hard Freeze (28°F): Feb 17 - Mar 3
  • First Hard Freeze (28°F): Nov 21 - Nov 30
  • Annual Rainfall: 50-65 inches
  • Common Soils: Loess, Alluvial clay, Sandy loam

Plant Zone Range (zones 2-11)

2a
11b
3a (Cold)13b (Hot)

Preferred Soil pH

3.5 (Acidic)7.0 (Neutral)9.0 (Alkaline)
Highlighted range: pH 5.58.0

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 Mississippi

The frost window

Across Mississippi, the last spring hard freeze (28°F) clears between Feb 17 and Mar 3, and the first fall hard freeze lands between Nov 21 and Nov 30 (NOAA Regional Climate Centers ACIS, 1991-2020). Counting from the latest last freeze to the earliest first freeze, that's a 263-day window you can count on — up to 286 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 Mississippi's late-side last freeze of Mar 3 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 183 days to spare even in Mississippi's tightest freeze scenario — room for a later start or a second sowing.

Timing tuned to sub-state frost dates — Tishomingo 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 Mississippi site sees ~273 (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 ~5404 GDD (from PRISM 1991-2020 climate normals), so Mississippi'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 Mississippi's loess and alluvial clay — 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 Mississippi soil test result is a problem or just a number. Drainage matters: this plant wants well (dry spells). If your Mississippi 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 30.3% of Mississippi 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. Mississippi 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 Mississippi

Zone compatibility tells you about winter cold survival — but Mississippi growers also need to think about:

Extreme summer heat and humidity

Heavy alluvial clay in the Delta region

Frequent severe storms and flooding

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 Mississippi — wet is: with roughly 30.3% 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 Mississippi grower, not just sunflower — is covered on the Mississippi growing guide.

Timing shifts within Mississippi

Mississippi isn't one climate. In Tishomingo County, the last hard freeze (28°F) holds until about Mar 23 — 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 Tishomingo County — Mississippi’s shortest season at 232 frost-free days — clears that by 162 days, so season length isn’t the constraint anywhere in Mississippi. What varies is your own parcel.

Across Mississippi’s 82 counties the frost-free season runs from 232 days in Tishomingo County to 309 days in Harrison County — a spread of 77 days, which is why a single statewide planting date misleads. The median Mississippi county sees 273 frost-free days, leaving sunflower about 203 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 Mississippi's frost window — roughly 273 days, opening after the last 28°F freeze (Feb 17 - Mar 3) and closing at the first (Nov 21 - Nov 30), per NOAA Regional Climate Centers ACIS, 1991-2020.

Recommended Sunflower Varieties for Mississippi

Mississippi publishes no state variety trial for sunflower, so we won't invent a "best for Mississippi" list. Choose types rated to your USDA hardiness zone (7b-9b), and confirm winter survival and drainage against your own parcel.

Mississippi Cooperative Extension

For Mississippi-specific cultivar recommendations, planting calendars, and pest pressure for sunflower, the canonical source is Mississippi State University Extension Service. Their fact sheets carry the local trial data we can't generalize across 50 states.

Is Sunflower native to Mississippi?

Yes — the USDA PLANTS Database (accessed 2026-07-01) documents Sunflower as native to Mississippi. 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 Mississippi

When can I plant Sunflower in Mississippi?

Mississippi's last spring hard freeze (28°F) clears between Feb 17 and Mar 3, and the first fall hard freeze lands between Nov 21 and Nov 30 (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 Mississippi?

Yes — Sunflower matures in 80 days (Growable Ground Plant Database), and Mississippi's dependable hard-freeze-free window runs 263 days (NOAA Regional Climate Centers ACIS, 1991-2020), leaving 183 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 Mississippi?

Mississippi 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 Mississippi site have?

A typical Mississippi site sees ~273 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 Tishomingo, the freeze-free season runs shorter than the state average, so verify your own county's window.

Is Sunflower native to Mississippi?

Yes — the USDA PLANTS Database (accessed 2026-07-01) documents Sunflower as native to Mississippi. Planting it supports the pollinators and wildlife that evolved alongside it.

How should I amend the soil for Sunflower in Mississippi?

Sunflower prefers pH 5.5-8 and well (dry spells) drainage (FAO ECOCROP). That sits in the common-ground band across Mississippi 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 Mississippi?

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.

Free Report

Check your specific parcel in Mississippi

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 Mississippi sunflower averages can't show:

Your soil pHYour frost-free days — Mississippi averages 273Your sun & shade

We read public map data around Mississippi — soil, climate, flood, and parcel records. How we handle your address.

25+ data sources read at your address, not the Mississippi 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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