Barnhart, Missouri, sits in USDA hardiness zone 7a — enough range to grow cool-season vegetables, hardy fruit, and warm-season crops that mature before the first hard frost.
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.
Even in Barnhart, 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 Barnhart 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 Barnhart — soil, climate, flood, and parcel records. How we handle your address.
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Barnhart — the short answer
Barnhart, Missouri: USDA zone 7a, about 228 days between hard freezes, across 3K acres of town.
- USDA zone
- 7a
- USDA PHZM 2023
- Last hard freeze (28°F)
- Mar 24
- NOAA 1991–2020 Climate Normals, 28°F — this town
- First hard freeze (28°F)
- Nov 7
- NOAA 1991–2020 Climate Normals, 28°F — this town
- Days between freezes
- ~228
- NOAA 1991–2020 Climate Normals, 28°F — this town
- Town area
- 3K acres
- US Census TIGER/Line 2025
Every figure names the dataset it came from. Hard-freeze dates are this town’s own 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 Barnhart's average, not your lot's — a low corner or a tree line moves it. Against Barnhart's 228-day season, see what your own ground reads.
Soil varies lot by lot — soil types explained.
What this means for growing in Barnhart
Each reading below is measured for Barnhart itself — here is what it means for a garden here, and the move an experienced grower makes about it.
Season length
MeasuredBarnhart runs about 228 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
MeasuredBarnhart 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 Barnhart is in
Barnhart sits in the Ozark Highlands — EPA Level III, inside the wider Eastern Temperate Forests. That is read at Barnhart's own centroid rather than borrowed from Jefferson County.
What Grows in Barnhart
Every plant below cleared Barnhart's own zone 7a and its 228-day season. Each card opens that plant's Missouri profile. How we score.
Is it too late to plant in Barnhart?
Almost never — the real question is what to plant next. Cool-season crops can go in from around Feb 24; tender transplants wait until two to three weeks after the last 28°F hard freeze, which lands near Mar 24 (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. With a season this long, “too late” mostly means “switch crops” — second sowings and a full fall garden are the norm, with garlic closing the year.
Documented around Barnhart
Survey cells within 31 miles of Barnhart checked for spotted lanternfly, none carrying a detection — a surveyed negative, not an absence of looking. Nearest documented record 254 miles off. What to watch for.
What's on the federal record near Barnhart
Closest first, within ~10 miles of Barnhart. Listing isn't leaking, and distance isn't exposure.
- T42N R06E 31BAD1Nitrate · 1800 ft
- WEIGH STATION C-5Underground Storage Tanks · 2400 ft
- SCHAEFER AUTO BODY CENTERSBrownfields · 2600 ft
- REDEMPTORIST FATHERSUnderground Storage Tanks · 2600 ft
- T42N R06E 31ABB1Nitrate · 0.5 mi
- T42N R06E 30BDB1Nitrate · 0.7 mi
- GENERAL VINYLS DBA BRAY COBrownfields · 0.7 mi
- EXPRESS MART WESTUnderground Storage Tanks · 0.7 mi
- K.C. OIL COUnderground Storage Tanks · 0.8 mi
- WALLIS PETROLEUM #518Underground Storage Tanks · 0.9 mi
- EXPRESS MART BARNHARTUnderground Storage Tanks · 0.9 mi
- T42N R06E 31DCB1Nitrate · 0.9 mi
6 more sites are on the record inside the same radius. See them on the map
Measured from Barnhart'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 Barnhart.
Sources Checked
within ~10 miles of Barnhart
Severity Distribution
within ~10 miles of Barnhart
Highest-Severity Sites
A note from Gnorman
What an experienced grower watches for around here
In and around Barnhart, two things run higher than the national average within ~10 miles of Barnhart — PFAS (9 sites) and Nitrate (144 sites). That's not a problem with your land — it's information about it.
PFAS: PFAS (per- and polyfluoroalkyl substances) are called "forever chemicals" because they do not biodegrade.
Nitrate: Nitrate contamination primarily comes from agricultural fertilizer runoff and failing septic systems.
Test irrigation water source — this is the primary pathway for PFAS to reach garden crops.
Test well water for nitrate if you rely on a private well for irrigation (EPA standard: 10 mg/L).
Check your specific parcel in Barnhart
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 Barnhart average
Your land is one point inside Barnhart
Everything above resolves to Barnhart as a whole — one PHZM band and one 28°F frost record, read across 3K 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 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 Barnhart Average
Barnhart Average
- ●USDA Zones 7a, averaged across Barnhart
- ●One soil character for all of Barnhart
- ●Frost dates read at Barnhart's scale: Mar 24 to Nov 7
YOUR Parcel
- ✓Your exact zone, not Barnhart's 7a
- ✓Your SSURGO soil type & pH
- ✓Your sun exposure, cast in 3D
See MY Growing Report
Read your specific parcel in Barnhart
Pull a site-specific report for your exact address in Barnhart, Missouri — soil, sun, drainage, frost risk, and scored plant recommendations.
Three things about your lot that Barnhart averages can't show:
We read public map data around Barnhart — soil, climate, flood, and parcel records. How we handle your address.
25+ data sources read at your address, not the Barnhart average
How we know this about Barnhart
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 Barnhart’s own record; 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 Barnhart
When does frost risk typically end in Barnhart?
The last hard freeze (28°F) in Barnhart typically lands around Mar 24, 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 14.
When is the first frost in Barnhart?
The first hard freeze (28°F) in Barnhart typically arrives around Nov 7, per NOAA 1991–2020 climate normals — the point tender summer crops finish. Lighter frosts run ahead of it, near Oct 24, so the watching starts about Oct 8 — about 228 days after the spring freeze cleared.
How long is the growing season in Barnhart?
Measured between 28°F hard freezes, Barnhart sees about 228 frost-free days — roughly Mar 24 through Nov 7, per NOAA 1991–2020 climate normals. Tender crops work a shorter one: nearer Apr 14 to Oct 24, about 193 days.
Is the soil safe to grow vegetables in Barnhart?
The federal record around Barnhart runs heavier than most — 516 documented sites, mostly Underground Storage Tanks entries (214), the nearest Nitrate record about 0.3 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.
How do I protect my plants from frost in Barnhart?
From about Oct 8 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 7 (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 7. Hardy greens and roots shrug off light frost and sweeten after it — leave them in.
Everything above is measured at Barnhart's scale — its 7a band and its 228-day season. Your yard writes its own version of Barnhart'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 Barnhart’s own scale
7 of the readings below were taken at Barnhart's own scale — its own ~228-day season between 28°F freezes, the 3,172 acres it covers and 516 documented sites around it; 4 are borrowed from a wider read, named and linked below.
Measured here
- Barnhart's own USDA hardiness band, zones 7aUSDA PHZM 2023
- Barnhart's own 28°F hard-freeze dates, about Mar 24 and Nov 7 and the ~228-day span between themNOAA 1991–2020 Climate Normals
- 516 documented contamination sites on the federal record near Barnhart, the closest Nitrate record about 0.3 miles out from the town centreFederal environmental registers
- Barnhart's boundary and the 3,172 acres inside itUS Census TIGER/Line 2025
- Which of 1,086 plants clear zones 7a and a ~228-day seasonGrowable Ground crop-matching engine
- The ecoregion at Barnhart's own centroid, the Ozark HighlandsUS EPA Level III Ecoregions
- Lanternfly survey cells around Barnhart checked, none carrying a detectionlydemapr (De Bona & Helmus), 10 km survey lattice
Inherited from a wider read
- Soil character — no town-scale survey exists, so Barnhart's 3,172 acres read through its county's SSURGO summaryfrom Jefferson County
- Growing-degree days and winter chill — measured county-wide only, so the county page carries themfrom Jefferson County
- The growing challenges every Missouri grower plans around — written at state scale, so they stay on the state guidefrom Missouri
- Butterfly and beetle records, and the farmland pesticide estimate — all published county-widefrom Jefferson County
What this page can’t tell you
- The soil pH, drainage, sun hours, and frost pockets on any one lot among Barnhart's 3,172 acreswhy one lot differs from the next →
- Which side of Barnhart you're on — a low spot frosts first and a south wall warms early, and one normal is being asked to speak for all 3,172 acresreading your own microclimate →
- How close that record sits to YOUR lot — the closest Nitrate record about 0.3 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 Barnhart-wide figureread your own land →
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