Ouachita County, in Arkansas, sits in USDA hardiness zone 8a — enough range to grow cool-season vegetables, hardy fruit, and warm-season crops that mature before the first hard frost.
Expect cabbage, fig, california poppy, and collard greens to be strong candidates here; the deciding factors on any one parcel stay local — soil, sun, and drainage.
Ouachita County lies within the West Gulf Coastal Plain (South Arkansas) — a regional growing area with its own character.
Grounded in USDA PHZM 2023 · Growable Ground suitability scoring · NOAA 1991–2020 Climate Normals
Ouachita County holds more than one microclimate.
Soils and elevations shift across Ouachita County, so your frost dates and drainage aren't the county average. 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 Ouachita County — soil, climate, flood, and parcel records. How we handle your address.
No card required · your full report in seconds
Ouachita County — the short answer
Ouachita County, Arkansas: USDA zone 8a, about 265 days between hard freezes, across 469K acres.
- USDA zone
- 8a
- USDA PHZM 2023
- Last hard freeze (28°F)
- Feb 28
- NOAA 1991–2020 Climate Normals, 28°F
- First hard freeze (28°F)
- Nov 20
- NOAA 1991–2020 Climate Normals, 28°F
- Days between freezes
- ~265
- NOAA 1991–2020 Climate Normals, 28°F
- County area
- 469K acres
- US Census TIGER/Line 2025
Every figure names the dataset it came from. Hard-freeze dates are county 28°F normals: light frosts run a few weeks past them, and tender transplants usually wait 2–3 weeks after the last hard freeze.
Hardiness Zone Range
Zone 8a is Ouachita County's average, not your lot's — a low corner or a tree line moves it. Against Ouachita County's 265-day season, see what your own ground reads.
Heat and winter chill in Ouachita County
Across a year, Ouachita County accumulates about 5,220 growing degree days above 50°F, about 414 more than the middle Arkansas county — ahead of 62 of Arkansas’s 75 counties. Degree days are the heat a crop actually gets to work with — more of them is more room to ripen a long-season crop before the freeze closes the window.
Winter banks about 1,467 hours below 45°F, 313 fewer than the Arkansas middle of 1,780. Chill is what tells a fruit tree its dormancy is over, and it is set by climate rather than by anything you can build.
Grounded in PRISM Climate Group, Oregon State University — 1991–2020 monthly normals
Soil in Ouachita County
Across Ouachita County, the ground is predominantly Ultisols, where Amy, Kirvin, and Sacul are the most extensive named soil series. The soil is generally well drained with a fine sandy loam surface. Topsoil pH runs about 4.8–5.3, very strongly acidic. Rainfall drains through hydrologic group C soils.
Soil order
Ultisols
Drainage
Well drained
Prime farmland
19%
Hydric soils
35%
Soil still varies lot by lot — soil types explained.
How the ground varies across Ouachita County
The USDA soil survey maps 41% of Ouachita County as well drained — but another 57% drains differently: 40% poorly drained, 11% moderately well drained.
Amy is the most extensive named soil at 25% of mapped acres, then Kirvin (19%) and Sacul (10%).
Which of them your own lot sits on is a parcel question, not a county one. Check your address for the survey at your boundary.
What this means for growing in Ouachita County
Each reading below is measured for Ouachita County itself — here is what it means for a garden here, and the move an experienced grower makes about it.
Drainage
MeasuredThe dominant soils across Ouachita County are well drained, in hydrologic group C — ground that drains quickly.
The upside is soil you can work early in spring and roots that never drown; the cost is that fast-draining ground dries out fast and leaches nutrients away before plants can use them.
Work in compost and mulch to hold moisture and feed, and water more often in short doses than deep and rarely.
USDA NRCS SSURGO
Surface pH
MeasuredTopsoil across Ouachita County runs about pH 4.8–5.3, on the acidic side.
Blueberries, potatoes, and rhododendrons thrive in it, but most vegetables start locking out nutrients below about pH 6.0 and grow pale and stunted no matter how much you feed them.
A measured lime application raises pH for the crops that need it — but test first, because the right rate depends on your own soil, not the county average.
USDA NRCS SSURGO
Wet ground
MeasuredAbout 35% of Ouachita County is mapped as hydric — wetland — soil.
If your lot falls in one of those pockets, a standard in-ground bed will fight waterlogging all season, and roots that need air will struggle.
Check how your own ground drains before you dig; raised beds or moisture-loving plantings turn a wet corner from a problem into a niche.
USDA NRCS SSURGO
Season length
MeasuredOuachita County runs about 265 days between hard freezes — 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
The kind of country Ouachita County is in
Ouachita County sits in the South Central Plains — EPA Level III, inside the wider Eastern Temperate Forests. One consistent ecological setting across the whole county.
What Grows in Ouachita County
We scored all 1,086 plants against Ouachita County's own USDA zone 8a and its own 265-day season between hard freezes, using the same matching engine that runs a full parcel report. These cleared both. Sun, soil pH and drainage vary lot by lot — those are the parcel questions below. Each card opens that plant's Arkansas profile.
Is it too late to plant in Ouachita County?
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 31; tender transplants wait until two to three weeks after the last 28°F hard freeze, which lands near Feb 28 (NOAA 1991–2020 climate normals); and from midsummer, planting counts back from the first fall freeze around Nov 20 — long-season crops need about 90 days of runway, quick greens only 30. With almost year-round growing weather, timing is about heat and rainfall more than frost — some bench is always in play.
Documented around Ouachita County
- monarch butterfly1 documented records
Sighting records, so they follow observers as much as insects.
What gets applied to farmland in Ouachita County
USGS estimates 1,405 lb of 2,4-d on Ouachita County farmland in 2019, its largest by weight, ahead of Glyphosate (268 lb) and Triclopyr (262 lb).
Farmland across the whole county, not any one lot. Check your address for the site-by-site record.
Safe to Grow Here?
What the federal record shows across Ouachita County — and how to grow with it.
We checked the federal record across Ouachita County — 407 documented sites across 6 of the 9 source types we track.
The most significant on record: 1 Superfund site. Sites tracked in EPA's Superfund program — from assessment-stage CERCLIS entries to confirmed National Priorities List cleanup sites.
There's a meaningful federal record across Ouachita County — worth a look before you plant food, not a reason to hold back from growing. Proximity to a documented site is information, not a diagnosis of any one yard. A soil test before new food beds is the sensible precaution here, and the map shows exactly which sites sit where, so you can see what's actually near you.
Sources: EPA, USGS — 1.8M documented sites tracked nationwide across 9 federal source types.
What's on the federal record near Ouachita County
Closest first, across Ouachita County. Listing isn't leaking, and distance isn't exposure.
- CHARLIE'S 7 TILL (OLD)Underground Storage Tanks · 1500 ft
- YMARTUnderground Storage Tanks · 1600 ft
- FASTSTOPUnderground Storage Tanks · 1900 ft
- ARKANSAS FORESTRY COMMISSIONUnderground Storage Tanks · 2400 ft
- ANDERS GROCERY & STATIONUnderground Storage Tanks · 0.6 mi
- 13S17W19ABB2Nitrate · 0.8 mi
- 13S17W19ABB3Nitrate · 0.9 mi
- 13S17W19BDC1Nitrate · 1.2 mi
- INTERNATIONAL PAPER COMPANYUnderground Storage Tanks · 1.3 mi
- 13S17W19CCA1Nitrate · 1.4 mi
- STURGIS SUBDIVISON--LOT 2Underground Storage Tanks · 1.4 mi
- HIGHLAND RESOURCE PARKUnderground Storage Tanks · 1.4 mi
6 more sites are on the record inside the same radius. See them on the map
Measured from Ouachita County'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 Ouachita County.
Sources Checked
across Ouachita County
Severity Distribution
across Ouachita County
Highest-Severity Sites
A note from Gnorman
What an experienced grower watches for around here
In and around Ouachita County, Nitrate runs higher than the national average — 166 sites across Ouachita County. It's not cause for alarm — it's worth knowing, and there's a sensible way to grow around it.
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 Ouachita County
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 Ouachita County average
Your land is one point inside Ouachita County
Everything above resolves to Ouachita County as a whole — one PHZM band and one county frost record, read across 469K acres. 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 county 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 county average.
Your Lot vs the Ouachita County Average
Ouachita County Average
- ●USDA Zones 8a, averaged across Ouachita County
- ●One soil character for all of Ouachita County
- ●Frost dates read at Ouachita County's scale: Feb 28 to Nov 20
YOUR Parcel
- ✓Your exact zone, not Ouachita County's 8a
- ✓Your SSURGO soil type & pH
- ✓Your sun exposure, cast in 3D
See MY Growing Report
Read your parcel in Ouachita County
Pull a site-specific report for your exact address in Ouachita County, Arkansas — soil, sun, drainage, frost risk, and scored plant recommendations.
Three things about your lot that Ouachita County averages can't show:
We read public map data around Ouachita County — soil, climate, flood, and parcel records. How we handle your address.
25+ data sources read at your address, not the Ouachita County average
How we know this about Ouachita County
The datasets: hardiness from the USDA ARS Plant Hardiness Zone Map 2023, read at county grain; hard-freeze dates from NOAA 1991–2020 28°F normals at this county’s own record where one resolves, and the labelled statewide window where none does; soils from the USDA NRCS SSURGO survey, area-weighted across the county’s own map units; boundaries and acreage from US Census TIGER/Line 2025; the contamination and pesticide records from the federal sources named in their beats above. Where Ouachita County carries no record of its own, the figure is inherited and labelled — the resolution ledger below names each.
Common questions about Ouachita County
When does frost risk typically end in Ouachita County?
The last hard freeze (28°F) in Ouachita County typically lands around Feb 28, 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 21.
How long is the growing season in Ouachita County?
Measured between 28°F hard freezes, Ouachita County sees about 265 frost-free days — roughly Feb 28 through Nov 20, per NOAA 1991–2020 climate normals. Tender crops work a shorter one: nearer Mar 21 to Nov 6, about 230 days.
Is the soil safe to grow vegetables in Ouachita County?
The federal record around Ouachita County is a meaningful one — 407 documented sites, mostly Underground Storage Tanks entries (194), the nearest Underground Storage Tanks record about 0.3 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.
Everything above is measured at Ouachita County's scale — its 8a band and its 265-day season. Your yard writes its own version of Ouachita County's numbers: we read soil, sun, drainage and frost at your exact address. Try it for 14 days — no card required.
Will It Grow Here?
Zone fit is the first question — each answer below reads Arkansas's frost window, season length, and soil profile against the plant's real requirements.
What this page reads at Ouachita County’s own scale
9 of the readings below were taken at Ouachita County's own scale — its own ~265-day span between 28°F freezes, the 3 most extensive soil series mapped here and 407 documented sites inside its boundary; one is borrowed from a wider read, named and linked below.
Measured here
- Ouachita County's own USDA hardiness band, zones 8aUSDA PHZM 2023
- Ouachita County's own 28°F hard-freeze dates and its ~265-day span between themNOAA 1991–2020 Climate Normals
- The soil order, drainage, surface pH, and the 3 most extensive named soil series mapped in Ouachita CountyUSDA NRCS SSURGO
- 407 documented contamination sites inside the county boundary, distance-sorted from its center — the closest Underground Storage Tanks record about 0.3 miles outFederal environmental registers
- Ouachita County's boundary and the 468,941 acres inside itUS Census TIGER/Line 2025
- Which of 1,086 plants clear zones 8a and a ~265-day seasonGrowable Ground crop-matching engine
- Ouachita County sitting wholly inside the South Central PlainsUS EPA Level III Ecoregions
- Open occurrence records documented in Ouachita County for a tracked speciesGBIF derived datasets (CC0 / CC BY 4.0)
- Which agricultural compounds go onto Ouachita County farmland, and roughly how muchUSGS NAWQA EPest county estimates
Inherited from a wider read
- The growing challenges every Arkansas grower plans around — written at state scale, so they stay on the state guidefrom Arkansas
What this page can’t tell you
- How the season shifts across Ouachita County — the ~265 days above is one reading at its centre; the 12 towns below each carry their owntowns in this county →
- The soil pH, drainage, sun hours, and frost pockets on any one lot among Ouachita County's 468,941 acreswhy one lot differs from the next →
- Which of those 407 documented sites actually reaches your soil — that needs your address, the wind, and the groundwater directionhow we read the record →
- Where cold air settles, which slopes face the sun, and which way the wind runs on your own ground — none of it survives being averaged over Ouachita Countyread your own land →