Calvin, Louisiana, sits in USDA hardiness zone 8b — enough range to grow cool-season vegetables, hardy fruit, and warm-season crops that mature before the first hard frost.
Growers here do well with cabbage, fig, california poppy, and collard greens — with the usual caveat that any single yard's soil, sun, and drainage cast the deciding vote.
Even in Calvin, no two yards are alike.
A low spot, a south-facing slope, or a stand of trees moves the frost date and sun across a single Calvin lot. Enter your address and we'll score 1,086 plants against your land's actual soil, sun, and frost.
We read public map data around Calvin — soil, climate, flood, and parcel records. How we handle your address.
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Calvin — the short answer
Calvin, Louisiana: USDA zone 8b, about 281 days between hard freezes, across 1K acres of town.
- USDA zone
- 8b
- USDA PHZM 2023
- Last hard freeze (28°F)
- Feb 19
- Winn Parish normal — NOAA 1991–2020, nearest to this town
- First hard freeze (28°F)
- Nov 27
- Winn Parish normal — NOAA 1991–2020, nearest to this town
- Days between freezes
- ~281
- Winn Parish normal — NOAA 1991–2020, nearest to this town
- Town area
- 1K acres
- US Census TIGER/Line 2025
Every figure names the dataset it came from. No 30-year normal resolves at this town’s own centroid, so the hard-freeze dates are Winn Parish’s — the closest measured record, labelled as such rather than passed off as local.
Hardiness Zone Range
Zone 8b is Calvin's average, not your lot's — a low corner or a tree line moves it. Against Calvin's 281-day season, see what your own ground reads.
Soil varies lot by lot — soil types explained.
What this means for growing in Calvin
Each reading below is measured for Calvin itself — here is what it means for a garden here, and the move an experienced grower makes about it.
Season length
From county recordsCalvin runs about 281 days between hard freezes (read from Winn Parish, the closest normal to Calvin) — close to year-round growing.
Frost is rarely the limit here; winter plantings are as real as summer ones, and the harder question is which crops shrug off the summer heat.
Grow cool-season crops through the mild winter, and choose heat-tolerant varieties for the summer beds.
NOAA 1991–2020 Climate Normals
Winter hardiness
MeasuredCalvin sits in USDA hardiness zone 8b.
The zone sets which perennials, shrubs, and fruit trees live through an average winter here — a plant rated for a colder zone is a safe bet, one rated warmer needs winter protection or gets treated as an annual.
Match perennials and fruit to the zone before you buy, so nothing you plant is a gamble against the cold.
USDA PHZM 2023
The kind of country Calvin is in
Calvin sits in the South Central Plains — EPA Level III, inside the wider Eastern Temperate Forests. That is read at Calvin's own centroid rather than borrowed from Winn Parish.
What Grows in Calvin
Every plant below cleared Calvin's own zone 8b and its 281-day season. Each card opens that plant's Louisiana profile. How we score.
Is it too late to plant in Calvin?
For most of the year, no — what changes is which crops still fit the days remaining. Cool-season crops can go in from around Jan 22; tender transplants wait until two to three weeks after the last 28°F hard freeze, which lands near Feb 19 (NOAA 1991–2020 climate normals); and from midsummer, planting counts back from the first fall freeze around Nov 27 — long-season crops need about 90 days of runway, quick greens only 30. And with a calendar this mild, the honest answer is that planting barely stops — winter opens seasons colder regions never see.
What's on the federal record near Calvin
Closest first, within ~10 miles of Calvin. Listing isn't leaking, and distance isn't exposure.
- Calvin Food CenterUnderground Storage Tanks · 1300 ft
- General StoreUnderground Storage Tanks · 1300 ft
- Corner Grocery & MarketUnderground Storage Tanks · 1300 ft
- W-143Nitrate · 1500 ft
- W-14Nitrate · 2200 ft
- W-127Nitrate · 2200 ft
- Garrett GroceryUnderground Storage Tanks · 2200 ft
- Diamond C Enterprises IncUnderground Storage Tanks · 2200 ft
- W-81Nitrate · 1.1 mi
- WINN CORRECTIONAL CENTERBrownfields · 2.4 mi
- W-147Nitrate · 2.8 mi
- W-76Nitrate · 4.4 mi
6 more sites are on the record inside the same radius. See them on the map
Measured from Calvin's center, not your beds. Run your own address for what's upwind of you specifically.
Environmental Intelligence
The counts behind that headline — every source type on the record near Calvin.
Sources Checked
within ~10 miles of Calvin
Severity Distribution
within ~10 miles of Calvin
Highest-Severity Sites
A note from Gnorman
What an experienced grower watches for around here
In and around Calvin, Nitrate runs higher than the national average — 74 sites within ~10 miles of Calvin. Knowing it is half the work — and it's nothing a thoughtful grower can't plan for.
Nitrate: Nitrate contamination primarily comes from agricultural fertilizer runoff and failing septic systems.
Test well water for nitrate if you rely on a private well for irrigation (EPA standard: 10 mg/L).
Check your specific parcel in Calvin
Get exact proximity distances to contamination sources for your specific parcel — plus soil, sun, drainage, and 1,086 plant recommendations.
25+ data sources read at your address, not the Calvin average
Your land is one point inside Calvin
Everything above resolves to Calvin as a whole — one PHZM band, read across 1K acres, with hard-freeze dates borrowed from Winn Parish’s record because no 30-year normal resolves at this town’s own centroid. Your parcel is one point inside that footprint. Slope, tree cover, a low spot that pools cold air, and what is in the soil are all resolved at the address, and none of them are visible at town scale. That is the honest boundary of this page, and the reason the next step is a reading of your own ground rather than a better local average.
Your Lot vs the Calvin Average
Calvin Average
- ●USDA Zones 8b, averaged across Calvin
- ●One soil character for all of Calvin
- ●Frost dates read at Calvin's scale: Feb 19 to Nov 27
YOUR Parcel
- ✓Your exact zone, not Calvin's 8b
- ✓Your SSURGO soil type & pH
- ✓Your sun exposure, cast in 3D
See MY Growing Report
Read your specific parcel in Calvin
Pull a site-specific report for your exact address in Calvin, Louisiana — soil, sun, drainage, frost risk, and scored plant recommendations.
Three things about your lot that Calvin averages can't show:
We read public map data around Calvin — soil, climate, flood, and parcel records. How we handle your address.
25+ data sources read at your address, not the Calvin average
How we know this about Calvin
The datasets: hardiness from the USDA ARS Plant Hardiness Zone Map 2023, read at this town’s own centroid; hard-freeze dates from NOAA 1991–2020 28°F normals at Winn Parish’s record, because none resolves here; boundaries and acreage from US Census TIGER/Line 2025; the contamination records from the federal sources named in their beats above. Soil is not read at town grain anywhere on this page — there is no town-resolution survey in our data, which is why you will find no soil grid here rather than a statewide one wearing a local label. The resolution ledger below names every figure this page inherited.
Common questions about Calvin
When does frost risk typically end in Calvin?
The last hard freeze (28°F) in Calvin typically lands around Feb 19, per NOAA 1991–2020 climate normals — earlier than the light-frost dates most charts quote. That marks the hard freeze, not the last light frost — lighter frosts keep biting past it, which is why tender transplants here wait until about Mar 12.
When is the first frost in Calvin?
The first hard freeze (28°F) in Calvin typically arrives around Nov 27, per NOAA 1991–2020 climate normals — the point tender summer crops finish. Lighter frosts run ahead of it, near Nov 13, so the watching starts about Oct 28 — about 281 days after the spring freeze cleared.
How long is the growing season in Calvin?
Measured between 28°F hard freezes, Calvin sees about 281 frost-free days — roughly Feb 19 through Nov 27, per NOAA 1991–2020 climate normals. Tender crops work a shorter one: nearer Mar 12 to Nov 13, about 246 days.
Is the soil safe to grow vegetables in Calvin?
The federal record around Calvin is a meaningful one — 212 documented sites, mostly Underground Storage Tanks entries (83), the nearest Underground Storage Tanks record about 0.2 miles out — so a soil test before new food beds is a sensible precaution here, not a reason to hold back from growing. Remember that proximity to a documented site is information, not a diagnosis of any one yard; the contamination map shows exactly what sits where.
How do I protect my plants from frost in Calvin?
From about Oct 28 the job here turns from planting to protecting — the last start even a 30-day crop can finish. As the season closes around the first 28°F hard freeze near Nov 27 (NOAA 1991–2020 climate normals), three moves buy time: row cover or an old sheet over tender plants on still, clear nights; water the soil the afternoon before a freeze, so it holds warmth overnight; and harvest tomatoes, peppers and basil before Nov 27. Hardy greens and roots shrug off light frost and sweeten after it — leave them in.
Everything above is measured at Calvin's scale — its 8b band and its 281-day season. Your yard writes its own version of Calvin's numbers: we read soil, sun, drainage and frost at your exact address. Try it for 14 days — no card required.
What this page reads at Calvin’s own scale
5 of the readings below were taken at Calvin's own scale — the 1,468 acres it covers and 212 documented sites around it; 5 are borrowed from a wider read, named and linked below.
Measured here
- Calvin's own USDA hardiness band, zones 8bUSDA PHZM 2023
- 212 documented contamination sites on the federal record near Calvin, the closest Underground Storage Tanks record about 0.2 miles out from the town centreFederal environmental registers
- Calvin's boundary and the 1,468 acres inside itUS Census TIGER/Line 2025
- Which of 1,086 plants clear zones 8b and a ~281-day seasonGrowable Ground crop-matching engine
- The ecoregion at Calvin's own centroid, the South Central PlainsUS EPA Level III Ecoregions
Inherited from a wider read
- The 28°F hard-freeze dates — Calvin has no normal of its own, so its county's is the closest measured readfrom Winn Parish
- Soil character — no town-scale survey exists, so Calvin's 1,468 acres read through its county's SSURGO summaryfrom Winn County
- Growing-degree days and winter chill — measured county-wide only, so the county page carries themfrom Winn County
- The growing challenges every Louisiana grower plans around — written at state scale, so they stay on the state guidefrom Louisiana
- Butterfly and beetle records, and the farmland pesticide estimate — all published county-widefrom Winn County
What this page can’t tell you
- The soil pH, drainage, sun hours, and frost pockets on any one lot among Calvin's 1,468 acreswhy one lot differs from the next →
- Which side of Calvin you're on — a low spot frosts first and a south wall warms early, and one normal is being asked to speak for all 1,468 acresreading your own microclimate →
- How close that record sits to YOUR lot — the closest Underground Storage Tanks record about 0.2 miles out, measured from the town centrehow we read the record →
- Where cold air settles, which slopes face the sun, and which way the wind runs on your own ground — measured at your address, and averaged away by any Calvin-wide figureread your own land →
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