Knob Noster, 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.
The conditions favor cabbage, hazelnut, lavender, and collard greens, among others — though every individual site edits that list with its own soil, sun, and drainage.
Even in Knob Noster, 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 Knob Noster 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 Knob Noster — soil, climate, flood, and parcel records. How we handle your address.
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Knob Noster — the short answer
Knob Noster, Missouri: USDA zone 6b, about 220 days between hard freezes, across 2K acres of city.
- USDA zone
- 6b
- USDA PHZM 2023
- Last hard freeze (28°F)
- Mar 29
- NOAA 1991–2020 Climate Normals, 28°F — this town
- First hard freeze (28°F)
- Nov 4
- NOAA 1991–2020 Climate Normals, 28°F — this town
- Days between freezes
- ~220
- NOAA 1991–2020 Climate Normals, 28°F — this town
- City area
- 2K 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 Knob Noster's average, not your lot's — a low corner or a tree line moves it. Against Knob Noster's 220-day season, see what your own ground reads.
Soil varies lot by lot — soil types explained.
What this means for growing in Knob Noster
Each reading below is measured for Knob Noster itself — here is what it means for a garden here, and the move an experienced grower makes about it.

Season length
MeasuredKnob Noster 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
MeasuredKnob Noster 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 Knob Noster is in
Knob Noster sits in the Central Irregular Plains — EPA Level III, inside the wider Great Plains. That is read at Knob Noster's own centroid rather than borrowed from Johnson County.
What Grows in Knob Noster
Every plant below cleared Knob Noster's own zone 6b and its 220-day season. Each card opens that plant's Missouri profile. How we score.






























Is it too late to plant in Knob Noster?
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 1; tender transplants wait until two to three weeks after the last 28°F hard freeze, which lands near Mar 29 (NOAA 1991–2020 climate normals); and from midsummer, planting counts back from the first fall freeze around Nov 4 — 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 Knob Noster
Survey cells within 31 miles of Knob Noster checked for spotted lanternfly, none carrying a detection — a surveyed negative, not an absence of looking. Nearest documented record 349 miles off. What to watch for.
What's on the federal record near Knob Noster
Closest first, within ~10 miles of Knob Noster. Listing isn't leaking, and distance isn't exposure.
- CASEYS GENERAL STORE #1949Underground Storage Tanks · 750 ft
- CASEYS GENERAL STORE #1091Underground Storage Tanks · 850 ft
- JOHN'S CONOCOUnderground Storage Tanks · 1900 ft
- SMILEY SERV STATION - CLOSEDUnderground Storage Tanks · 2000 ft
- T46N R24W 21ADNitrate · 2000 ft
- AMMONS TEXACO SERVICEUnderground Storage Tanks · 2200 ft
- KNOB NOSTER MAINT LOTUnderground Storage Tanks · 2300 ft
- HOWARDS READY MIXUnderground Storage Tanks · 2400 ft
- T46N R24W 21Nitrate · 2500 ft
- T46N R24W 22DCNitrate · 2500 ft
- T46N R24W 21DAD1Nitrate · 0.6 mi
- DELBERT BEARCEUnderground Storage Tanks · 0.8 mi
6 more sites are on the record inside the same radius. See them on the map
Measured from Knob Noster'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 Knob Noster.
Total Sites
151
within ~10 miles of Knob Noster
Risk Level
Elevated
Highest-severity
1 Superfund site (none NPL-listed)
Sources Checked
within ~10 miles of Knob Noster
Severity Distribution
within ~10 miles of Knob Noster
Highest-Severity Sites

A note from Gnorman
What an experienced grower watches for around here
In and around Knob Noster, two things run higher than the national average within ~10 miles of Knob Noster — CAFO (5 sites) and PFAS (3 sites). That's not a problem with your land — it's information about it.
CAFO: CAFOs pose a different contamination profile than chemical sources.
PFAS: PFAS (per- and polyfluoroalkyl substances) are called "forever chemicals" because they do not biodegrade.
Wash all produce consumed raw thoroughly, especially leafy greens grown near CAFOs.
Test irrigation water source — this is the primary pathway for PFAS to reach garden crops.
Check your specific parcel in Knob Noster
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 Knob Noster average
Your land is one point inside Knob Noster
Everything above resolves to Knob Noster as a whole — one PHZM band and one 28°F frost record, read across 2K 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 Knob Noster Average
Knob Noster Average
- ●USDA Zones 6b, averaged across Knob Noster
- ●One soil character for all of Knob Noster
- ●Frost dates read at Knob Noster's scale: Mar 29 to Nov 4
YOUR Parcel
- ✓Your exact zone, not Knob Noster's 6b
- ✓Your SSURGO soil type & pH
- ✓Your sun exposure, cast in 3D
See MY Growing Report
Read your specific parcel in Knob Noster
Pull a site-specific report for your exact address in Knob Noster, Missouri — soil, sun, drainage, frost risk, and scored plant recommendations.
Three things about your lot that Knob Noster averages can't show:
We read public map data around Knob Noster — soil, climate, flood, and parcel records. How we handle your address.
25+ data sources read at your address, not the Knob Noster average
How we know this about Knob Noster
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 Knob Noster’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 Knob Noster
When does frost risk typically end in Knob Noster?
The last hard freeze (28°F) in Knob Noster typically lands around Mar 29, 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 19.
When is the first frost in Knob Noster?
The first hard freeze (28°F) in Knob Noster typically arrives around Nov 4, per NOAA 1991–2020 climate normals — the point tender summer crops finish. Lighter frosts run ahead of it, near Oct 21, so the watching starts about Oct 5 — about 220 days after the spring freeze cleared.
How long is the growing season in Knob Noster?
Measured between 28°F hard freezes, Knob Noster sees about 220 frost-free days — roughly Mar 29 through Nov 4, per NOAA 1991–2020 climate normals. Tender crops work a shorter one: nearer Apr 19 to Oct 21, about 185 days.
Is the soil safe to grow vegetables in Knob Noster?
The federal record around Knob Noster is a meaningful one — 151 documented sites, mostly Underground Storage Tanks entries (67), the nearest Underground Storage Tanks record about 0.1 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 Knob Noster?
From about Oct 5 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 4 (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 4. Hardy greens and roots shrug off light frost and sweeten after it — leave them in.
Everything above is measured at Knob Noster's scale — its 6b band and its 220-day season. Your yard writes its own version of Knob Noster'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 Knob Noster’s own scale
7 of the readings below were taken at Knob Noster's own scale — its own ~220-day season between 28°F freezes, the 1,844 acres it covers and 151 documented sites around it; 4 are borrowed from a wider read, named and linked below.
Measured here
- Knob Noster's own USDA hardiness band, zones 6bUSDA PHZM 2023
- Knob Noster's own 28°F hard-freeze dates, about Mar 29 and Nov 4 and the ~220-day span between themNOAA 1991–2020 Climate Normals
- 151 documented contamination sites on the federal record near Knob Noster, the closest Underground Storage Tanks record about 0.1 miles out from the town centreFederal environmental registers
- Knob Noster's boundary and the 1,844 acres inside itUS Census TIGER/Line 2025
- Which of 1,086 plants clear zones 6b and a ~220-day seasonGrowable Ground crop-matching engine
- The ecoregion at Knob Noster's own centroid, the Central Irregular PlainsUS EPA Level III Ecoregions
- Lanternfly survey cells around Knob Noster 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 Knob Noster's 1,844 acres read through its county's SSURGO summaryfrom Johnson County
- Growing-degree days and winter chill — measured county-wide only, so the county page carries themfrom Johnson 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 Johnson County
What this page can’t tell you
- The soil pH, drainage, sun hours, and frost pockets on any one lot among Knob Noster's 1,844 acreswhy one lot differs from the next →
- Which side of Knob Noster you're on — a low spot frosts first and a south wall warms early, and one normal is being asked to speak for all 1,844 acresreading your own microclimate →
- How close that record sits to YOUR lot — the closest Underground Storage Tanks record about 0.1 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 Knob Noster-wide figureread your own land →
More in Missouri
Wider growing context
What grows across MissouriKnob Noster sits outside our named growing regions, so Missouri as a whole is its closest context here.
Nearby growing guides
