Yes — Strong Match
Swiss chard (zones 2-11) covers every zone Mississippi contains (7b-9b), so hardiness is not what limits it anywhere in the state.
Swiss Chard in Mississippi — the short answer
Swiss Chard in Mississippi: hardy in zones 2–11, part 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
- 55 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.
Mississippi spans zones 7b-9b, 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 swiss chard 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.
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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 swiss chard can finish before the first hard freeze.
The middle half of 82 counties runs 262–286 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 swiss chard (USDA PHZM 2023):
Zone Comparison
Swiss Chard Needs
- USDA Zones: 2-11
- Frost-Free Days: 160+
- Sun: Part Sun
- Mature size: 1.5 ft tall
- Picking window: ~90 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)
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 Swiss Chard 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
Swiss Chard 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
Swiss Chard is direct-sown where it grows rather than started under cover, so there is no seed-tray head start to bank — Mississippi'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 55 days to maturity (Growable Ground Plant Database), counting from the last hard freeze it ripens with 208 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 swiss chard survives winter here. Whether the season is long enough — and warm enough — is a different question.
Frost-free days
Swiss Chard wants 160+ 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
Swiss Chard needs ~700 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
Swiss Chard likes near-neutral soil (pH 5.5-7.5). 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 — 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
Whether swiss chard is safe to eat from Mississippi soil is a block-by-block question, not a town-wide one — 20,263 documented contamination sites mean levels spike on some parcels and not the one next door. Swiss Chard roots to about 19 inches, so it is the top 19 inches under your address that decide what it takes up, so only a test on your address settles it.
Check your parcel → Source: USDA NRCS SSURGO + EPA/state contamination databases.
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.
Before you plant swiss chard for food
Anything you grow to eat takes up what is in the ground it grows in, so what is on record near you is worth knowing before swiss chard goes in. What follows is Mississippi’s documented federal record at state scale — a screening signal, not a soil test, and not a statement about any one lot.
Safe to Grow Here?
What the federal record shows across Mississippi — and how to grow with it.
We checked the federal record across Mississippi — 20,263 documented sites across 8 of the 9 source types we track.
The most significant on record: 118 Superfund sites. Sites tracked in EPA's Superfund program — from assessment-stage CERCLIS entries to confirmed National Priorities List cleanup sites.
Mississippi carries one of the heavier federal records we track — and that's not a verdict on your yard. Proximity to a documented site is information, not a diagnosis: nothing here says any particular parcel is affected. It does earn one concrete step — before food beds go in the ground, a professional soil test tells you exactly what you're working with, and raised beds with clean imported soil grow well almost anywhere in the meantime.
Sources Checked
across Mississippi
Severity Distribution
across Mississippi
Highest-Severity Sites
A note from Gnorman
What an experienced grower watches for around here
In and around Mississippi, PFAS runs higher than the national average — 211 sites across Mississippi. Knowing it is half the work — and it's nothing a thoughtful grower can't plan for.
PFAS: PFAS (per- and polyfluoroalkyl substances) are called "forever chemicals" because they do not biodegrade.
Test irrigation water source — this is the primary pathway for PFAS to reach garden crops.
Sources: EPA, USGS — 1.8M documented sites tracked nationwide across 9 federal source types.
What Else to Consider for Swiss Chard 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 swiss chard here specifically
Swiss Chard grows its edible leaves in the soil itself, so on any of Mississippi's 20,263 documented contamination sites it can carry up lead you'd then eat.
Keep swiss chard in raised beds of screened clean soil and confirm your parcel's lead level before the first crop. How to handle it →
What to actually do about these — and the constraints that apply to every Mississippi grower, not just swiss chard — 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 swiss chard to your county's window, not the statewide date.
Swiss Chard needs about 160 days of frost-free season to complete its cycle. Even Tishomingo County — Mississippi’s shortest season at 232 frost-free days — clears that by 72 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 swiss chard about 113 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"). Swiss Chard's 160-day requirement: USDA PLANTS / Growable Ground plant database (minimum frost-free days). A parcel report resolves your address's own frost dates.
Mississippi Cooperative Extension
For Mississippi-specific cultivar recommendations, planting calendars, and pest pressure for swiss chard, the canonical source is Mississippi State University Extension Service. Their fact sheets carry the local trial data we can't generalize across 50 states.
Common Questions About Growing Swiss Chard in Mississippi
When can I plant Swiss Chard 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). Swiss Chard 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 Swiss Chard mature before first frost in Mississippi?
Yes — Swiss Chard matures in 55 days (Growable Ground Plant Database), and Mississippi's dependable hard-freeze-free window runs 263 days (NOAA Regional Climate Centers ACIS, 1991-2020), leaving 208 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 Swiss Chard grown in across Mississippi?
Mississippi spans USDA hardiness zones 7b-9b (USDA ARS PHZM 2023). Swiss Chard 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). Swiss Chard needs 160+ 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.
How should I amend the soil for Swiss Chard in Mississippi?
Swiss Chard prefers pH 5.5-7.5 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 Swiss Chard actually grow on my specific land in Mississippi?
State-level zone + climate data is a sketch. A Growable Ground parcel report scores swiss chard 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 Mississippi
State-level data is a sketch. Your Growable Ground report scores swiss chard against your parcel's exact soil, sun, drainage, and frost data — not zone averages.
Three things about your lot that Mississippi swiss chard averages can't show:
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 swiss chard average
Explore More
Growing guides for swiss chard
Explore Mississippi county by county
Mississippi carries 82 counties with their own USDA zone — a sample of the growing pages for swiss chard there:
Where else swiss chard grows
Swiss Chard's zone band crosses state lines — these are the states closest to Mississippi 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 Mississippi
Mississippi has a growing page for 1,034 plants — a rotating sample of the rest of the shelf.
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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