Miller County, in Missouri, sits in USDA hardiness zone 6b — 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, hazelnut, lavender, and collard greens — with the usual caveat that any single yard's soil, sun, and drainage cast the deciding vote.
Miller County lies within the Ozarks — a regional growing area with its own character.
Grounded in USDA PHZM 2023 · Growable Ground suitability scoring · NOAA 1991–2020 Climate Normals
Miller County holds more than one microclimate.
Soils and elevations shift across Miller 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 Miller County — soil, climate, flood, and parcel records. How we handle your address.
No card required · your full report in seconds
Miller County — the short answer
Miller County, Missouri: USDA zone 6b, about 224 days between hard freezes, across 379K acres.
- USDA zone
- 6b
- USDA PHZM 2023
- Last hard freeze (28°F)
- Mar 28
- NOAA 1991–2020 Climate Normals, 28°F
- First hard freeze (28°F)
- Nov 7
- NOAA 1991–2020 Climate Normals, 28°F
- Days between freezes
- ~224
- NOAA 1991–2020 Climate Normals, 28°F
- County area
- 379K 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 6b is Miller County's average, not your lot's — a low corner or a tree line moves it. Against Miller County's 224-day season, see what your own ground reads.
Heat in Miller County
Across a year, Miller County accumulates about 3,846 growing degree days above 50°F, about 93 more than the middle Missouri county — ahead of 76 of Missouri’s 115 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.
Grounded in PRISM Climate Group, Oregon State University — 1991–2020 monthly normals
Soil in Miller County
Across Miller County, the ground is predominantly Alfisols, where Rueter, Gravois, and Niangua are the most extensive named soil series. The soil is generally moderately well drained with a silt loam surface. Topsoil pH runs about 5.3–6.2, moderately acidic. Rainfall drains through hydrologic group D soils.
Soil order
Alfisols
Drainage
Moderately well drained
Prime farmland
4%
Hydric soils
2%
Soil still varies lot by lot — soil types explained.
How the ground varies across Miller County
The USDA soil survey maps 39% of Miller County as moderately well drained — but another 61% drains differently: 32% well drained, 22% somewhat excessively drained.
Rueter is the most extensive named soil at 22% of mapped acres, then Gravois (17%) and Niangua (11%).
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 Miller County
Each reading below is measured for Miller 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 Miller County are moderately well drained, in hydrologic group D — roughly the middle of the drainage range.
This is close to the middle most vegetables prefer: it holds enough water to carry a crop between rains without staying waterlogged. The catch is that a wet spring or a low corner can still tip it soggy.
Plant on the site as-is for most crops, but keep the lowest, slowest-draining beds for moisture-tolerant plantings.
USDA NRCS SSURGO
Surface pH
MeasuredTopsoil across Miller County runs about pH 5.3–6.2, 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
Season length
MeasuredMiller County runs about 224 days between hard freezes — a long growing season.
There is slack for succession plantings and slow-finishing crops: many vegetables can be sown twice, and the heat-lovers have time to ripen fully.
Plan a second sowing of quick crops after the first comes out, and use the fall window most gardeners let sit idle.
NOAA 1991–2020 Climate Normals
Winter hardiness
MeasuredMiller County sits in USDA hardiness zone 6b.
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 Miller County is in
Miller County sits in the Ozark Highlands — EPA Level III, inside the wider Eastern Temperate Forests. One consistent ecological setting across the whole county.
What Grows in Miller County
We scored all 1,086 plants against Miller County's own USDA zone 6b and its own 224-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 Missouri profile.
Is it too late to plant in Miller County?
Rarely: the season closes in stages, not all at once, and each stage has its crops. Cool-season crops can go in from around Feb 28; tender transplants wait until two to three weeks after the last 28°F hard freeze, which lands near Mar 28 (NOAA 1991–2020 climate normals); and from midsummer, planting counts back from the first fall freeze around Nov 7 — long-season crops need about 90 days of runway, quick greens only 30. There is slack in a calendar like this — late plantings, second rounds of favorites, and a fall bench that keeps beds working.
Documented around Miller County
Survey cells within 31 miles of Miller County checked for spotted lanternfly, none carrying a detection — a surveyed negative, not an absence of looking. Nearest documented record 333 miles off. What to watch for.
What gets applied to farmland in Miller County
USGS estimates 7,535 lb of Glyphosate on Miller County farmland in 2019, its largest by weight, ahead of 2,4-d (6,528 lb) and Atrazine (2,484 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 Miller County — and how to grow with it.
We checked the federal record across Miller County — 174 documented sites across 7 of the 9 source types we track.
The most significant on record: 8 Toxics Release Inventory facilities. Active industrial facilities reporting chemical releases to air, water, and land.
Miller County 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: EPA, USGS — 1.8M documented sites tracked nationwide across 9 federal source types.
What's on the federal record near Miller County
Closest first, across Miller County. Listing isn't leaking, and distance isn't exposure.
- PICKERING RIDGE FARMSCAFO · 1.9 mi
- PATTERSON, STEVECAFO · 2.0 mi
- TUSCUMBIA EAGLE STOPUnderground Storage Tanks · 2.0 mi
- B.J. MILLER OIL CO, INCUnderground Storage Tanks · 2.4 mi
- MARVIN AND ETHAN PATTERSONCAFO · 2.4 mi
- SLOAN FEEDUnderground Storage Tanks · 2.4 mi
- TUSCUMBIA MAINT BLDGUnderground Storage Tanks · 4.5 mi
- Grass Roots DiggingsMining · 4.7 mi
- Unknown-Lead & ZincMining · 4.7 mi
- DENNIS RUSHCAFO · 4.8 mi
- Unknown-LeadMining · 5.0 mi
- Capp DiggingsMining · 6.1 mi
6 more sites are on the record inside the same radius. See them on the map
Measured from Miller 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 Miller County.
Total Sites
174
across Miller County
Risk Level
High
Highest-severity
8 Toxics Release Inventory facilities
Severity Distribution
across Miller County
Highest-Severity Sites
A note from Gnorman
What an experienced grower watches for around here
In and around Miller County, two things run higher than the national average across Miller County — CAFO (18 sites) and Mining (27 sites). That's not a problem with your land — it's information about it.
CAFO: CAFOs pose a different contamination profile than chemical sources.
Mining: Mining sites — both historic and active — can leach heavy metals (arsenic, lead, cadmium, mercury) into soil and water for centuries after operations cease.
Wash all produce consumed raw thoroughly, especially leafy greens grown near CAFOs.
Test soil for heavy metals (lead, arsenic, cadmium, mercury) — this is essential near any mining site.
Check your specific parcel in Miller 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 Miller County average
Your land is one point inside Miller County
Everything above resolves to Miller County as a whole — one PHZM band and one county frost record, read across 379K 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 Miller County Average
Miller County Average
- ●USDA Zones 6b, averaged across Miller County
- ●One soil character for all of Miller County
- ●Frost dates read at Miller County's scale: Mar 28 to Nov 7
YOUR Parcel
- ✓Your exact zone, not Miller County's 6b
- ✓Your SSURGO soil type & pH
- ✓Your sun exposure, cast in 3D
See MY Growing Report
Read your parcel in Miller County
Pull a site-specific report for your exact address in Miller County, Missouri — soil, sun, drainage, frost risk, and scored plant recommendations.
Three things about your lot that Miller County averages can't show:
We read public map data around Miller County — soil, climate, flood, and parcel records. How we handle your address.
25+ data sources read at your address, not the Miller County average
How we know this about Miller 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 Miller County carries no record of its own, the figure is inherited and labelled — the resolution ledger below names each.
Common questions about Miller County
When does frost risk typically end in Miller County?
The last hard freeze (28°F) in Miller County typically lands around Mar 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 Apr 18.
How long is the growing season in Miller County?
Measured between 28°F hard freezes, Miller County sees about 224 frost-free days — roughly Mar 28 through Nov 7, per NOAA 1991–2020 climate normals. Tender crops work a shorter one: nearer Apr 18 to Oct 24, about 189 days.
Is the soil safe to grow vegetables in Miller County?
The federal record around Miller County runs heavier than most — 174 documented sites, mostly Underground Storage Tanks entries (73), the nearest CAFO record about 1.9 miles out — so test the soil before planting food in the ground, and raised beds with clean imported soil grow well in the meantime. Even here, proximity to a documented site is information, not a diagnosis of any one yard; the contamination map shows exactly what's recorded and where.
Everything above is measured at Miller County's scale — its 6b band and its 224-day season. Your yard writes its own version of Miller 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 Missouri's frost window, season length, and soil profile against the plant's real requirements.
What this page reads at Miller County’s own scale
8 of the readings below were taken at Miller County's own scale — its own ~224-day span between 28°F freezes, the 3 most extensive soil series mapped here and 174 documented sites inside its boundary; one is borrowed from a wider read, named and linked below.
Measured here
- Miller County's own USDA hardiness band, zones 6bUSDA PHZM 2023
- Miller County's own 28°F hard-freeze dates and its ~224-day span between themNOAA 1991–2020 Climate Normals
- The soil order, drainage, surface pH, and the 3 most extensive named soil series mapped in Miller CountyUSDA NRCS SSURGO
- 174 documented contamination sites inside the county boundary, distance-sorted from its center — the closest CAFO record about 1.9 miles outFederal environmental registers
- Miller County's boundary and the 379,252 acres inside itUS Census TIGER/Line 2025
- Which of 1,086 plants clear zones 6b and a ~224-day seasonGrowable Ground crop-matching engine
- Miller County sitting wholly inside the Ozark HighlandsUS EPA Level III Ecoregions
- Which agricultural compounds go onto Miller County farmland, and roughly how muchUSGS NAWQA EPest county estimates
Inherited from a wider read
- The growing challenges every Missouri grower plans around — written at state scale, so they stay on the state guidefrom Missouri
What this page can’t tell you
- How the season shifts across Miller County — the ~224 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 Miller County's 379,252 acreswhy one lot differs from the next →
- Which of those 174 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 Miller Countyread your own land →