Holt County, in Missouri, sits in USDA hardiness zone 6a — enough range to grow cool-season vegetables, hardy fruit, and warm-season crops that mature before the first hard frost.
These conditions suit cabbage, hazelnut, lavender, and collard greens — a starting list any specific site will trim or extend with its own soil, sun, and drainage.
Grounded in USDA PHZM 2023 · Growable Ground suitability scoring · NOAA 1991–2020 Climate Normals
Holt County holds more than one microclimate.
Soils and elevations shift across Holt 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 Holt County — soil, climate, flood, and parcel records. How we handle your address.
No card required · your full report in seconds
Holt County — the short answer
Holt County, Missouri: USDA zone 6a, about 206 days between hard freezes, across 296K acres.
- USDA zone
- 6a
- USDA PHZM 2023
- Last hard freeze (28°F)
- Apr 6
- NOAA 1991–2020 Climate Normals, 28°F
- First hard freeze (28°F)
- Oct 29
- NOAA 1991–2020 Climate Normals, 28°F
- Days between freezes
- ~206
- NOAA 1991–2020 Climate Normals, 28°F
- County area
- 296K 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 6a is Holt County's average, not your lot's — a low corner or a tree line moves it. Against Holt County's 206-day season, see what your own ground reads.
Heat in Holt County
Across a year, Holt County accumulates about 3,456 growing degree days above 50°F, about 297 fewer than the middle Missouri county — ahead of 21 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 Holt County
Across Holt County, the ground is predominantly Mollisols, where Leta, Contrary, and Timula are the most extensive named soil series. The soil is generally well drained with a silt loam surface. Topsoil pH runs about 6.1–7.4, neutral. Rainfall drains through hydrologic group C soils.
Soil order
Mollisols
Drainage
Well drained
Prime farmland
16%
Hydric soils
22%
Soil still varies lot by lot — soil types explained.
How the ground varies across Holt County
The USDA soil survey maps 50% of Holt County as well drained — but another 50% drains differently: 19% somewhat poorly drained, 19% poorly drained.
Leta is the most extensive named soil at 8% of mapped acres, then Contrary (6%) and Timula (6%).
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 Holt County
Each reading below is measured for Holt 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 Holt 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 Holt County runs about pH 6.1–7.4, close to neutral.
This is the range most vegetables prefer — one correction you probably do not have to make, which is genuinely good news for a new bed.
Keep it there with compost rather than lime or sulfur, and only amend if your own soil test says otherwise.
USDA NRCS SSURGO
Wet ground
MeasuredAbout 22% of Holt 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
MeasuredHolt County runs about 206 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
The kind of country Holt County is in
Holt County sits in the Western Corn Belt Plains — EPA Level III, inside the wider Great Plains. One consistent ecological setting across the whole county.
What Grows in Holt County
We scored all 1,086 plants against Holt County's own USDA zone 6a and its own 206-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 Holt 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 Mar 9; tender transplants wait until two to three weeks after the last 28°F hard freeze, which lands near Apr 6 (NOAA 1991–2020 climate normals); and from midsummer, planting counts back from the first fall freeze around Oct 29 — 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 Holt County
- monarch butterfly5 documented records
Sighting records, so they follow observers as much as insects.
What gets applied to farmland in Holt County
USGS estimates 202,562 lb of Glyphosate on Holt County farmland in 2019, its largest by weight, ahead of Metolachlor & Metolachlor-s (98,291 lb) and Atrazine (90,829 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 Holt County — and how to grow with it.
We checked the federal record across Holt County — 69 documented sites across 5 of the 9 source types we track.
The most significant on record: 3 Toxics Release Inventory facilities. Active industrial facilities reporting chemical releases to air, water, and land.
The federal record across Holt County is a modest one — a typical footprint for a growing area. Nothing here calls for alarm; it's worth knowing which recorded sites sit closest to where you grow, and each one on the map carries its type and location. If one turns out to be a near neighbor, a one-time soil test settles the question.
Sources: EPA, USGS — 1.8M documented sites tracked nationwide across 9 federal source types.
What's on the federal record near Holt County
Closest first, across Holt County. Listing isn't leaking, and distance isn't exposure.
- SQUAW CREEK NATIONAL WILDLIFE REFUGUnderground Storage Tanks · 1.9 mi
- SQUAW CREEK TRUCK PLAZAUnderground Storage Tanks · 2.0 mi
- MERZ FARM EQUIPMENTBrownfields · 2.0 mi
- THE HOLT COUNTY COOPERATIVE ASS'NUnderground Storage Tanks · 2.3 mi
- LAIDLAW TRANSIT INCBrownfields · 2.4 mi
- FARMERS OIL COUnderground Storage Tanks · 2.4 mi
- TERRY VESTUnderground Storage Tanks · 2.5 mi
- MOUND CITY MAINT LOTUnderground Storage Tanks · 2.6 mi
- T62N R38W 31CCC1Nitrate · 2.6 mi
- T62N R38W 31CCD 16907Nitrate · 2.6 mi
- EVERGY INC MOUND CITY SERVICE CENTERBrownfields · 2.6 mi
- GEORGES TOTALUnderground Storage Tanks · 2.7 mi
6 more sites are on the record inside the same radius. See them on the map
Measured from Holt 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 Holt County.
Total Sites
69
across Holt County
Risk Level
Moderate
Highest-severity
3 Toxics Release Inventory facilities
Sources Checked
across Holt County
Severity Distribution
across Holt County
Highest-Severity Sites
A note from Gnorman
What an experienced grower watches for around here
In and around Holt County, Nitrate runs higher than the national average — 38 sites across Holt 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 Holt 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 Holt County average
Your land is one point inside Holt County
Everything above resolves to Holt County as a whole — one PHZM band and one county frost record, read across 296K 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 Holt County Average
Holt County Average
- ●USDA Zones 6a, averaged across Holt County
- ●One soil character for all of Holt County
- ●Frost dates read at Holt County's scale: Apr 6 to Oct 29
YOUR Parcel
- ✓Your exact zone, not Holt County's 6a
- ✓Your SSURGO soil type & pH
- ✓Your sun exposure, cast in 3D
See MY Growing Report
Read your parcel in Holt County
Pull a site-specific report for your exact address in Holt County, Missouri — soil, sun, drainage, frost risk, and scored plant recommendations.
Three things about your lot that Holt County averages can't show:
We read public map data around Holt County — soil, climate, flood, and parcel records. How we handle your address.
25+ data sources read at your address, not the Holt County average
How we know this about Holt 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 Holt County carries no record of its own, the figure is inherited and labelled — the resolution ledger below names each.
Common questions about Holt County
When does frost risk typically end in Holt County?
The last hard freeze (28°F) in Holt County typically lands around Apr 6, 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 27.
How long is the growing season in Holt County?
Measured between 28°F hard freezes, Holt County sees about 206 frost-free days — roughly Apr 6 through Oct 29, per NOAA 1991–2020 climate normals. Tender crops work a shorter one: nearer Apr 27 to Oct 15, about 171 days.
Is the soil safe to grow vegetables in Holt County?
The federal record around Holt County shows 69 documented sites, mostly Nitrate entries (38), the nearest Underground Storage Tanks record about 1.9 miles out — a typical footprint for a growing area, and proximity to a documented site is information, not a diagnosis of any one yard. It's worth seeing which recorded sites sit closest to where you grow, and testing the soil before new food beds near any of them.
Everything above is measured at Holt County's scale — its 6a band and its 206-day season. Your yard writes its own version of Holt 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 Holt County’s own scale
9 of the readings below were taken at Holt County's own scale — its own ~206-day span between 28°F freezes, the 3 most extensive soil series mapped here and 69 documented sites inside its boundary; one is borrowed from a wider read, named and linked below.
Measured here
- Holt County's own USDA hardiness band, zones 6aUSDA PHZM 2023
- Holt County's own 28°F hard-freeze dates and its ~206-day span between themNOAA 1991–2020 Climate Normals
- The soil order, drainage, surface pH, and the 3 most extensive named soil series mapped in Holt CountyUSDA NRCS SSURGO
- 69 documented contamination sites inside the county boundary, distance-sorted from its center — the closest Underground Storage Tanks record about 1.9 miles outFederal environmental registers
- Holt County's boundary and the 296,125 acres inside itUS Census TIGER/Line 2025
- Which of 1,086 plants clear zones 6a and a ~206-day seasonGrowable Ground crop-matching engine
- Holt County sitting wholly inside the Western Corn Belt PlainsUS EPA Level III Ecoregions
- Open occurrence records documented in Holt County for a tracked speciesGBIF derived datasets (CC0 / CC BY 4.0)
- Which agricultural compounds go onto Holt 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 Holt County — the ~206 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 Holt County's 296,125 acreswhy one lot differs from the next →
- Which of those 69 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 Holt Countyread your own land →