Silex, Missouri, sits in USDA hardiness zone 6b — enough range to grow cool-season vegetables, hardy fruit, and warm-season crops that mature before the first hard frost.
Among the crops suited to this profile: cabbage, hazelnut, lavender, and collard greens. The site-level story — soil, sun, drainage — decides the rest.
Even in Silex, 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 Silex 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 Silex — soil, climate, flood, and parcel records. How we handle your address.
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Silex — the short answer
Silex, Missouri: USDA zone 6b, about 224 days between hard freezes, across 184 acres of city.
- USDA zone
- 6b
- USDA PHZM 2023
- Last hard freeze (28°F)
- Mar 28
- 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
- ~224
- NOAA 1991–2020 Climate Normals, 28°F — this town
- City area
- 184 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 Silex's average, not your lot's — a low corner or a tree line moves it. Against Silex's 224-day season, see what your own ground reads.
Soil varies lot by lot — soil types explained.
What this means for growing in Silex
Each reading below is measured for Silex itself — here is what it means for a garden here, and the move an experienced grower makes about it.
Season length
MeasuredSilex runs about 224 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
MeasuredSilex 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 Silex is in
Silex sits in the Interior River Valleys and Hills — EPA Level III, inside the wider Eastern Temperate Forests. That is read at Silex's own centroid rather than borrowed from Lincoln County.
What Grows in Silex
Every plant below cleared Silex's own zone 6b and its 224-day season. Each card opens that plant's Missouri profile. How we score.
Is it too late to plant in Silex?
Rarely: the season closes in stages, not all at once, and each stage has its crops. 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 7 — 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.
What's on the federal record near Silex
Closest first, within ~10 miles of Silex. Listing isn't leaking, and distance isn't exposure.
- SILEX R 1Brownfields · 900 ft
- T50N R01W 06CAA1Nitrate · 900 ft
- SILEX R-1 SCHOOLSUnderground Storage Tanks · 1200 ft
- J & L PACKAGEUnderground Storage Tanks · 1500 ft
- DEAN QUIGLEYUnderground Storage Tanks · 1500 ft
- ENTERPRISE STOREUnderground Storage Tanks · 1500 ft
- ROBERTS OIL COUnderground Storage Tanks · 1600 ft
- CENTRAL ELEV INCUnderground Storage Tanks · 2.1 mi
- S & J MARKETUnderground Storage Tanks · 3.1 mi
- MILLWOOD MAINT LOTUnderground Storage Tanks · 4.0 mi
- WHITESIDE STOREUnderground Storage Tanks · 4.5 mi
- HARPER'S WELDING & AUTOUnderground Storage Tanks · 4.6 mi
6 more sites are on the record inside the same radius. See them on the map
Measured from Silex'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 Silex.
Total Sites
31
within ~10 miles of Silex
Risk Level
Moderate
Highest-severity
1 Toxics Release Inventory facility
Sources Checked
within ~10 miles of Silex
Severity Distribution
within ~10 miles of Silex
Highest-Severity Sites
A note from Gnorman
What an experienced grower watches for around here
In and around Silex, Underground Storage Tanks runs higher than the national average — 21 sites within ~10 miles of Silex. It's not cause for alarm — it's worth knowing, and there's a sensible way to grow around it.
Underground Storage Tanks: Underground storage tanks are the single most common source of soil contamination near homes and gardens.
Use raised beds with imported soil — this eliminates the primary soil-contact pathway.
Check your specific parcel in Silex
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 Silex average
Your land is one point inside Silex
Everything above resolves to Silex as a whole — one PHZM band and one 28°F frost record, read across 184 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 Silex Average
Silex Average
- ●USDA Zones 6b, averaged across Silex
- ●One soil character for all of Silex
- ●Frost dates read at Silex's scale: Mar 28 to Nov 7
YOUR Parcel
- ✓Your exact zone, not Silex's 6b
- ✓Your SSURGO soil type & pH
- ✓Your sun exposure, cast in 3D
See MY Growing Report
Read your specific parcel in Silex
Pull a site-specific report for your exact address in Silex, Missouri — soil, sun, drainage, frost risk, and scored plant recommendations.
Three things about your lot that Silex averages can't show:
We read public map data around Silex — soil, climate, flood, and parcel records. How we handle your address.
25+ data sources read at your address, not the Silex average
How we know this about Silex
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 Silex’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 Silex
When does frost risk typically end in Silex?
The last hard freeze (28°F) in Silex 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.
When is the first frost in Silex?
The first hard freeze (28°F) in Silex 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 224 days after the spring freeze cleared.
How long is the growing season in Silex?
Measured between 28°F hard freezes, Silex sees about 224 frost-free days — roughly Mar 28 through Nov 7, per NOAA 1991–2020 climate normals. Tender crops work a shorter one: nearer Apr 18 to Oct 24, about 189 days.
Is the soil safe to grow vegetables in Silex?
The federal record around Silex shows 31 documented sites, mostly Underground Storage Tanks entries (21), the nearest Brownfields record about 0.2 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.
How do I protect my plants from frost in Silex?
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 Silex's scale — its 6b band and its 224-day season. Your yard writes its own version of Silex'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 Silex’s own scale
6 of the readings below were taken at Silex's own scale — its own ~224-day season between 28°F freezes, the 184 acres it covers and 31 documented sites around it; 4 are borrowed from a wider read, named and linked below.
Measured here
- Silex's own USDA hardiness band, zones 6bUSDA PHZM 2023
- Silex's own 28°F hard-freeze dates, about Mar 28 and Nov 7 and the ~224-day span between themNOAA 1991–2020 Climate Normals
- 31 documented contamination sites on the federal record near Silex, the closest Brownfields record about 0.2 miles out from the town centreFederal environmental registers
- Silex's boundary and the 184 acres inside itUS Census TIGER/Line 2025
- Which of 1,086 plants clear zones 6b and a ~224-day seasonGrowable Ground crop-matching engine
- The ecoregion at Silex's own centroid, the Interior River Valleys and HillsUS EPA Level III Ecoregions
Inherited from a wider read
- Soil character — no town-scale survey exists, so Silex's 184 acres read through its county's SSURGO summaryfrom Lincoln County
- Growing-degree days and winter chill — measured county-wide only, so the county page carries themfrom Lincoln 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 Lincoln County
What this page can’t tell you
- The soil pH, drainage, sun hours, and frost pockets on any one lot among Silex's 184 acreswhy one lot differs from the next →
- Which side of Silex you're on — a low spot frosts first and a south wall warms early, and one normal is being asked to speak for all 184 acresreading your own microclimate →
- How close that record sits to YOUR lot — the closest Brownfields record about 0.2 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 Silex-wide figureread your own land →
More in Missouri
Wider growing context
What grows across MissouriSilex sits outside our named growing regions, so Missouri as a whole is its closest context here.
Nearby growing guides