Dardenne Prairie, Missouri, sits in USDA hardiness zone 6b — a band that supports both cool-season staples and warm-season crops chosen to fit the local frost window.
On paper, cabbage, hazelnut, lavender, and collard greens all suit these conditions — on the ground, soil, sun, and drainage make the final call.
Even in Dardenne Prairie, 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 Dardenne Prairie 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 Dardenne Prairie — soil, climate, flood, and parcel records. How we handle your address.
No card required · your full report in seconds
Dardenne Prairie — the short answer
Dardenne Prairie, Missouri: USDA zone 6b, about 227 days between hard freezes, across 3K acres of city.
- USDA zone
- 6b
- USDA PHZM 2023
- Last hard freeze (28°F)
- Mar 26
- NOAA 1991–2020 Climate Normals, 28°F — this town
- First hard freeze (28°F)
- Nov 8
- NOAA 1991–2020 Climate Normals, 28°F — this town
- Days between freezes
- ~227
- NOAA 1991–2020 Climate Normals, 28°F — this town
- City 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 6b is Dardenne Prairie's average, not your lot's — a low corner or a tree line moves it. Against Dardenne Prairie's 227-day season, see what your own ground reads.
Soil varies lot by lot — soil types explained.
What this means for growing in Dardenne Prairie
Each reading below is measured for Dardenne Prairie itself — here is what it means for a garden here, and the move an experienced grower makes about it.
Season length
MeasuredDardenne Prairie runs about 227 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
MeasuredDardenne Prairie 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 Dardenne Prairie is in
Dardenne Prairie sits in the Interior River Valleys and Hills — EPA Level III, inside the wider Eastern Temperate Forests. That is read at Dardenne Prairie's own centroid rather than borrowed from St. Charles County.
What Grows in Dardenne Prairie
Every plant below cleared Dardenne Prairie's own zone 6b and its 227-day season. Each card opens that plant's Missouri profile. How we score.
Is it too late to plant in Dardenne Prairie?
Usually not — gardeners here simply switch what goes in the ground as the season moves. Cool-season crops can go in from around Feb 26; tender transplants wait until two to three weeks after the last 28°F hard freeze, which lands near Mar 26 (NOAA 1991–2020 climate normals); and from midsummer, planting counts back from the first fall freeze around Nov 8 — long-season crops need about 90 days of runway, quick greens only 30. A long window like this one runs successions deep into fall — and even its last weeks take quick greens and garlic.
Documented around Dardenne Prairie
Survey cells within 31 miles of Dardenne Prairie checked for spotted lanternfly, none carrying a detection — a surveyed negative, not an absence of looking. Nearest documented record 249 miles off. What to watch for.
What's on the federal record near Dardenne Prairie
Closest first, within ~10 miles of Dardenne Prairie. Listing isn't leaking, and distance isn't exposure.
- 46N3E-17.1b1Nitrate · 0.7 mi
- T46N R03E 19BANitrate · 0.9 mi
- T46N R03E 19ACNitrate · 1.0 mi
- ST CHARLES COUNTY PWSD 2PFAS · 1.0 mi
- PROGRESS WEST HOSPITALBrownfields · 1.1 mi
- T46N R03E 19BDNitrate · 1.1 mi
- TARGET STORE T1241Brownfields · 1.1 mi
- T46N R03E 08DBD1Nitrate · 1.1 mi
- CVS PHARMACY #18017Brownfields · 1.2 mi
- COMPONENT BAR PRODUCTS INC-ST CHARLESBrownfields · 1.2 mi
- COMPONENT BAR PRODUCTS INC-ST CHARLESToxics Release Inventory · 1.2 mi
- BUTLER DESIGN SERVICESBrownfields · 1.3 mi
6 more sites are on the record inside the same radius. See them on the map
Measured from Dardenne Prairie'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 Dardenne Prairie.
Total Sites
956
within ~10 miles of Dardenne Prairie
Risk Level
Elevated
Highest-severity
4 Superfund sites
Sources Checked
within ~10 miles of Dardenne Prairie
Severity Distribution
within ~10 miles of Dardenne Prairie
Highest-Severity Sites
A note from Gnorman
What an experienced grower watches for around here
In and around Dardenne Prairie, Nitrate runs higher than the national average — 284 sites within ~10 miles of Dardenne Prairie. That's not a problem with your land — it's information about 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 Dardenne Prairie
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 Dardenne Prairie average
Your land is one point inside Dardenne Prairie
Everything above resolves to Dardenne Prairie 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 city 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 Dardenne Prairie Average
Dardenne Prairie Average
- ●USDA Zones 6b, averaged across Dardenne Prairie
- ●One soil character for all of Dardenne Prairie
- ●Frost dates read at Dardenne Prairie's scale: Mar 26 to Nov 8
YOUR Parcel
- ✓Your exact zone, not Dardenne Prairie's 6b
- ✓Your SSURGO soil type & pH
- ✓Your sun exposure, cast in 3D
See MY Growing Report
Read your specific parcel in Dardenne Prairie
Pull a site-specific report for your exact address in Dardenne Prairie, Missouri — soil, sun, drainage, frost risk, and scored plant recommendations.
Three things about your lot that Dardenne Prairie averages can't show:
We read public map data around Dardenne Prairie — soil, climate, flood, and parcel records. How we handle your address.
25+ data sources read at your address, not the Dardenne Prairie average
How we know this about Dardenne Prairie
The datasets: hardiness from the USDA ARS Plant Hardiness Zone Map 2023, read at this city’s own centroid; hard-freeze dates from NOAA 1991–2020 28°F normals at Dardenne Prairie’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 city grain anywhere on this page — there is no city-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 Dardenne Prairie
When does frost risk typically end in Dardenne Prairie?
The last hard freeze (28°F) in Dardenne Prairie typically lands around Mar 26, 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 16.
When is the first frost in Dardenne Prairie?
The first hard freeze (28°F) in Dardenne Prairie typically arrives around Nov 8, per NOAA 1991–2020 climate normals — the point tender summer crops finish. Lighter frosts run ahead of it, near Oct 25, so the watching starts about Oct 9 — about 227 days after the spring freeze cleared.
How long is the growing season in Dardenne Prairie?
Measured between 28°F hard freezes, Dardenne Prairie sees about 227 frost-free days — roughly Mar 26 through Nov 8, per NOAA 1991–2020 climate normals. Tender crops work a shorter one: nearer Apr 16 to Oct 25, about 192 days.
Is the soil safe to grow vegetables in Dardenne Prairie?
The federal record around Dardenne Prairie is a meaningful one — 956 documented sites, mostly Underground Storage Tanks entries (314), the nearest Nitrate record about 0.7 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.
How do I protect my plants from frost in Dardenne Prairie?
From about Oct 9 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 8 (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 8. Hardy greens and roots shrug off light frost and sweeten after it — leave them in.
Everything above is measured at Dardenne Prairie's scale — its 6b band and its 227-day season. Your yard writes its own version of Dardenne Prairie'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 Dardenne Prairie’s own scale
7 of the readings below were taken at Dardenne Prairie's own scale — its own ~227-day season between 28°F freezes, the 3,416 acres it covers and 956 documented sites around it; 4 are borrowed from a wider read, named and linked below.
Measured here
- Dardenne Prairie's own USDA hardiness band, zones 6bUSDA PHZM 2023
- Dardenne Prairie's own 28°F hard-freeze dates, about Mar 26 and Nov 8 and the ~227-day span between themNOAA 1991–2020 Climate Normals
- 956 documented contamination sites on the federal record near Dardenne Prairie, the closest Nitrate record about 0.7 miles out from the town centreFederal environmental registers
- Dardenne Prairie's boundary and the 3,416 acres inside itUS Census TIGER/Line 2025
- Which of 1,086 plants clear zones 6b and a ~227-day seasonGrowable Ground crop-matching engine
- The ecoregion at Dardenne Prairie's own centroid, the Interior River Valleys and HillsUS EPA Level III Ecoregions
- Lanternfly survey cells around Dardenne Prairie 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 Dardenne Prairie's 3,416 acres read through its county's SSURGO summaryfrom St. Charles County
- Growing-degree days and winter chill — measured county-wide only, so the county page carries themfrom St. Charles 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 St. Charles County
What this page can’t tell you
- The soil pH, drainage, sun hours, and frost pockets on any one lot among Dardenne Prairie's 3,416 acreswhy one lot differs from the next →
- Which side of Dardenne Prairie you're on — a low spot frosts first and a south wall warms early, and one normal is being asked to speak for all 3,416 acresreading your own microclimate →
- How close that record sits to YOUR lot — the closest Nitrate record about 0.7 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 Dardenne Prairie-wide figureread your own land →
More in Missouri
Wider growing context
What grows across MissouriDardenne Prairie sits outside our named growing regions, so Missouri as a whole is its closest context here.
Nearby growing guides