Oregon County, in Missouri, sits in USDA hardiness zone 7a — a zone band wide enough that plant choice, not possibility, is the interesting question.
Crops well matched to these conditions include cabbage, hazelnut, california poppy, and collard greens — though what thrives on any one site still turns on its specific soil, sun, and drainage.
Oregon 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
Oregon County holds more than one microclimate.
Soils and elevations shift across Oregon 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 Oregon County — soil, climate, flood, and parcel records. How we handle your address.
No card required · your full report in seconds
Oregon County — the short answer
Oregon County, Missouri: USDA zone 7a, about 220 days between hard freezes, across 506K acres.
- USDA zone
- 7a
- USDA PHZM 2023
- Last hard freeze (28°F)
- Mar 28
- NOAA 1991–2020 Climate Normals, 28°F
- First hard freeze (28°F)
- Nov 3
- NOAA 1991–2020 Climate Normals, 28°F
- Days between freezes
- ~220
- NOAA 1991–2020 Climate Normals, 28°F
- County area
- 506K 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 7a is Oregon County's average, not your lot's — a low corner or a tree line moves it. Against Oregon County's 220-day season, see what your own ground reads.
Heat in Oregon County
Across a year, Oregon County accumulates about 3,922 growing degree days above 50°F, about 169 more than the middle Missouri county — ahead of 89 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 Oregon County
Across Oregon County, the ground is predominantly Ultisols, where Alred, Scholten, and Poynor are the most extensive named soil series. The soil is generally well drained with a very gravelly silt loam surface. Topsoil pH runs about 4.8–5.4, strongly acidic. Rainfall drains through hydrologic group D soils.
Soil order
Ultisols
Drainage
Well drained
Prime farmland
13%
Hydric soils
2%
Soil still varies lot by lot — soil types explained.
How the ground varies across Oregon County
The USDA soil survey maps 45% of Oregon County as well drained — but another 54% drains differently: 30% moderately well drained, 20% somewhat excessively drained.
Alred is the most extensive named soil at 16% of mapped acres, then Scholten (13%) and Poynor (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 Oregon County
Each reading below is measured for Oregon 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 Oregon County are well drained, in hydrologic group D — 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 Oregon County runs about pH 4.8–5.4, 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
MeasuredOregon County runs about 220 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
MeasuredOregon County sits in USDA hardiness zone 7a.
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 Oregon County is in
Oregon 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 Oregon County
We scored all 1,086 plants against Oregon County's own USDA zone 7a and its own 220-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 Oregon County?
Too late for some crops, right on time for others — a growing season is a sequence, not a deadline. 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 3 — long-season crops need about 90 days of runway, quick greens only 30. Here the season winds down slowly: late sowings, a real autumn harvest, and garlic in the ground before the first hard freeze.
Documented around Oregon County
Survey cells within 31 miles of Oregon County checked for spotted lanternfly, none carrying a detection — a surveyed negative, not an absence of looking. Nearest documented record 264 miles off. What to watch for.
What gets applied to farmland in Oregon County
USGS estimates 28,191 lb of 2,4-d on Oregon County farmland in 2019, its largest by weight, ahead of Glyphosate (1,919 lb) and Chlorpyrifos (313 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 Oregon County — and how to grow with it.
We checked the federal record across Oregon County — 86 documented sites across 4 of the 9 source types we track.
The most significant on record: 4 mining sites. Historic and active mines that may leach heavy metals like arsenic, lead, and cadmium.
The federal record across Oregon 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 Oregon County
Closest first, across Oregon County. Listing isn't leaking, and distance isn't exposure.
- OREGON COUNTY R-IV SCHOOLUnderground Storage Tanks · 1900 ft
- SOUTHSIDE STATIONUnderground Storage Tanks · 2600 ft
- HUFSTEDLER'S STOREUnderground Storage Tanks · 0.6 mi
- T24N R04W 33DBC1Nitrate · 0.6 mi
- T24N R04W 34 1Nitrate · 0.7 mi
- ALTON FUEL CENTERUnderground Storage Tanks · 0.7 mi
- OZARK SCENIC RIVERS CAMPGROUNDUnderground Storage Tanks · 0.7 mi
- CITY OF ALTONUnderground Storage Tanks · 0.7 mi
- T24N R04W 34CBNitrate · 0.7 mi
- WRIGHTS 66 STATIONUnderground Storage Tanks · 0.8 mi
- ALTON QUICK CONNECTIONUnderground Storage Tanks · 0.9 mi
- ALTON QUICK CONNECTION INCBrownfields · 0.9 mi
6 more sites are on the record inside the same radius. See them on the map
Measured from Oregon 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 Oregon County.
Sources Checked
across Oregon County
Severity Distribution
across Oregon County
Highest-Severity Sites
A note from Gnorman
What an experienced grower watches for around here
In and around Oregon County, Nitrate runs higher than the national average — 38 sites across Oregon 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 Oregon 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 Oregon County average
Your land is one point inside Oregon County
Everything above resolves to Oregon County as a whole — one PHZM band and one county frost record, read across 506K 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 Oregon County Average
Oregon County Average
- ●USDA Zones 7a, averaged across Oregon County
- ●One soil character for all of Oregon County
- ●Frost dates read at Oregon County's scale: Mar 28 to Nov 3
YOUR Parcel
- ✓Your exact zone, not Oregon County's 7a
- ✓Your SSURGO soil type & pH
- ✓Your sun exposure, cast in 3D
See MY Growing Report
Read your parcel in Oregon County
Pull a site-specific report for your exact address in Oregon County, Missouri — soil, sun, drainage, frost risk, and scored plant recommendations.
Three things about your lot that Oregon County averages can't show:
We read public map data around Oregon County — soil, climate, flood, and parcel records. How we handle your address.
25+ data sources read at your address, not the Oregon County average
How we know this about Oregon 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 Oregon County carries no record of its own, the figure is inherited and labelled — the resolution ledger below names each.
Common questions about Oregon County
When does frost risk typically end in Oregon County?
The last hard freeze (28°F) in Oregon 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 Oregon County?
Measured between 28°F hard freezes, Oregon County sees about 220 frost-free days — roughly Mar 28 through Nov 3, per NOAA 1991–2020 climate normals. Tender crops work a shorter one: nearer Apr 18 to Oct 20, about 185 days.
Is the soil safe to grow vegetables in Oregon County?
The federal record around Oregon County shows 86 documented sites, mostly Underground Storage Tanks entries (41), the nearest Underground Storage Tanks record about 0.4 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 Oregon County's scale — its 7a band and its 220-day season. Your yard writes its own version of Oregon 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 Oregon County’s own scale
8 of the readings below were taken at Oregon County's own scale — its own ~220-day span between 28°F freezes, the 3 most extensive soil series mapped here and 86 documented sites inside its boundary; one is borrowed from a wider read, named and linked below.
Measured here
- Oregon County's own USDA hardiness band, zones 7aUSDA PHZM 2023
- Oregon County's own 28°F hard-freeze dates and its ~220-day span between themNOAA 1991–2020 Climate Normals
- The soil order, drainage, surface pH, and the 3 most extensive named soil series mapped in Oregon CountyUSDA NRCS SSURGO
- 86 documented contamination sites inside the county boundary, distance-sorted from its center — the closest Underground Storage Tanks record about 0.4 miles outFederal environmental registers
- Oregon County's boundary and the 505,500 acres inside itUS Census TIGER/Line 2025
- Which of 1,086 plants clear zones 7a and a ~220-day seasonGrowable Ground crop-matching engine
- Oregon County sitting wholly inside the Ozark HighlandsUS EPA Level III Ecoregions
- Which agricultural compounds go onto Oregon 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 Oregon County — the ~220 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 Oregon County's 505,500 acreswhy one lot differs from the next →
- Which of those 86 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 Oregon Countyread your own land →