St. Robert, Missouri, sits in USDA hardiness zone 6b — room for a real mix of vegetables, fruit, and perennials matched to the local frost calendar.
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 St. Robert, 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 St. Robert 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 St. Robert — soil, climate, flood, and parcel records. How we handle your address.
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St. Robert — the short answer
St. Robert, Missouri: USDA zone 6b, about 216 days between hard freezes, across 5K 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)
- Oct 31
- NOAA 1991–2020 Climate Normals, 28°F — this town
- Days between freezes
- ~216
- NOAA 1991–2020 Climate Normals, 28°F — this town
- City area
- 5K 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 St. Robert's average, not your lot's — a low corner or a tree line moves it. Against St. Robert's 216-day season, see what your own ground reads.
Soil varies lot by lot — soil types explained.
What this means for growing in St. Robert
Each reading below is measured for St. Robert itself — here is what it means for a garden here, and the move an experienced grower makes about it.
Season length
MeasuredSt. Robert runs about 216 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
MeasuredSt. Robert 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 St. Robert is in
St. Robert sits in the Ozark Highlands — EPA Level III, inside the wider Eastern Temperate Forests. That is read at St. Robert's own centroid rather than borrowed from Pulaski County.
What Grows in St. Robert
Every plant below cleared St. Robert's own zone 6b and its 216-day season. Each card opens that plant's Missouri profile. How we score.
Is it too late to plant in St. Robert?
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 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 Oct 31 — 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 St. Robert
Survey cells within 31 miles of St. Robert checked for spotted lanternfly, none carrying a detection — a surveyed negative, not an absence of looking. Nearest documented record 323 miles off. What to watch for.
What's on the federal record near St. Robert
Closest first, within ~10 miles of St. Robert. Listing isn't leaking, and distance isn't exposure.
- MURPHY USA #7605Underground Storage Tanks · 550 ft
- WALMART SUPERCENTER #21Brownfields · 600 ft
- M-7 ST ROBERTSUnderground Storage Tanks · 1700 ft
- MOBIL ON THE RUNUnderground Storage Tanks · 2000 ft
- ST ROBERTS SHELLUnderground Storage Tanks · 2100 ft
- KUM & GO #578Underground Storage Tanks · 2300 ft
- LOWES OF ST ROBERT MO #2769Brownfields · 0.5 mi
- MERCY MEDICAL GROUPUnderground Storage Tanks · 0.5 mi
- OAKWOOD QUICK SHOPUnderground Storage Tanks · 0.6 mi
- ST ROBERT BP STATIONUnderground Storage Tanks · 0.7 mi
- CENEXUnderground Storage Tanks · 0.7 mi
- OAKWOOD TEXACOUnderground Storage Tanks · 0.7 mi
6 more sites are on the record inside the same radius. See them on the map
Measured from St. Robert'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 St. Robert.
Total Sites
274
within ~10 miles of St. Robert
Risk Level
Elevated
Highest-severity
1 Superfund site (none NPL-listed)
Sources Checked
within ~10 miles of St. Robert
Severity Distribution
within ~10 miles of St. Robert
Highest-Severity Sites
A note from Gnorman
What an experienced grower watches for around here
In and around St. Robert, two things run higher than the national average within ~10 miles of St. Robert — Nitrate (198 sites) and PFAS (5 sites). 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.
PFAS: PFAS (per- and polyfluoroalkyl substances) are called "forever chemicals" because they do not biodegrade.
Test well water for nitrate if you rely on a private well for irrigation (EPA standard: 10 mg/L).
Test irrigation water source — this is the primary pathway for PFAS to reach garden crops.
Check your specific parcel in St. Robert
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 St. Robert average
Your land is one point inside St. Robert
Everything above resolves to St. Robert as a whole — one PHZM band and one 28°F frost record, read across 5K 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 St. Robert Average
St. Robert Average
- ●USDA Zones 6b, averaged across St. Robert
- ●One soil character for all of St. Robert
- ●Frost dates read at St. Robert's scale: Mar 29 to Oct 31
YOUR Parcel
- ✓Your exact zone, not St. Robert's 6b
- ✓Your SSURGO soil type & pH
- ✓Your sun exposure, cast in 3D
See MY Growing Report
Read your specific parcel in St. Robert
Pull a site-specific report for your exact address in St. Robert, Missouri — soil, sun, drainage, frost risk, and scored plant recommendations.
Three things about your lot that St. Robert averages can't show:
We read public map data around St. Robert — soil, climate, flood, and parcel records. How we handle your address.
25+ data sources read at your address, not the St. Robert average
How we know this about St. Robert
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 St. Robert’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 St. Robert
When does frost risk typically end in St. Robert?
The last hard freeze (28°F) in St. Robert 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 St. Robert?
The first hard freeze (28°F) in St. Robert typically arrives around Oct 31, per NOAA 1991–2020 climate normals — the point tender summer crops finish. Lighter frosts run ahead of it, near Oct 17, so the watching starts about Oct 1 — about 216 days after the spring freeze cleared.
How long is the growing season in St. Robert?
Measured between 28°F hard freezes, St. Robert sees about 216 frost-free days — roughly Mar 29 through Oct 31, per NOAA 1991–2020 climate normals. Tender crops work a shorter one: nearer Apr 19 to Oct 17, about 181 days.
Is the soil safe to grow vegetables in St. Robert?
The federal record around St. Robert is a meaningful one — 274 documented sites, mostly Nitrate entries (198), 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 St. Robert?
From about Oct 1 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 Oct 31 (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 Oct 31. Hardy greens and roots shrug off light frost and sweeten after it — leave them in.
Everything above is measured at St. Robert's scale — its 6b band and its 216-day season. Your yard writes its own version of St. Robert'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 St. Robert’s own scale
7 of the readings below were taken at St. Robert's own scale — its own ~216-day season between 28°F freezes, the 5,390 acres it covers and 274 documented sites around it; 4 are borrowed from a wider read, named and linked below.
Measured here
- St. Robert's own USDA hardiness band, zones 6bUSDA PHZM 2023
- St. Robert's own 28°F hard-freeze dates, about Mar 29 and Oct 31 and the ~216-day span between themNOAA 1991–2020 Climate Normals
- 274 documented contamination sites on the federal record near St. Robert, the closest Underground Storage Tanks record about 0.1 miles out from the town centreFederal environmental registers
- St. Robert's boundary and the 5,390 acres inside itUS Census TIGER/Line 2025
- Which of 1,086 plants clear zones 6b and a ~216-day seasonGrowable Ground crop-matching engine
- The ecoregion at St. Robert's own centroid, the Ozark HighlandsUS EPA Level III Ecoregions
- Lanternfly survey cells around St. Robert 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 St. Robert's 5,390 acres read through its county's SSURGO summaryfrom Pulaski County
- Growing-degree days and winter chill — measured county-wide only, so the county page carries themfrom Pulaski 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 Pulaski County
What this page can’t tell you
- The soil pH, drainage, sun hours, and frost pockets on any one lot among St. Robert's 5,390 acreswhy one lot differs from the next →
- Which side of St. Robert you're on — a low spot frosts first and a south wall warms early, and one normal is being asked to speak for all 5,390 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 St. Robert-wide figureread your own land →
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