Hartsburg, Illinois, sits in USDA hardiness zone 6a — a band that supports both cool-season staples and warm-season crops chosen to fit the local frost window.
Expect cabbage, hazelnut, lavender, and collard greens to be strong candidates here; the deciding factors on any one parcel stay local — soil, sun, and drainage.
Even in Hartsburg, 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 Hartsburg 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 Hartsburg — soil, climate, flood, and parcel records. How we handle your address.
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Hartsburg — the short answer
Hartsburg, Illinois: USDA zone 6a, about 206 days between hard freezes, across 96 acres of town.
- USDA zone
- 6a
- USDA PHZM 2023
- Last hard freeze (28°F)
- Apr 5
- NOAA 1991–2020 Climate Normals, 28°F — this town
- First hard freeze (28°F)
- Oct 28
- NOAA 1991–2020 Climate Normals, 28°F — this town
- Days between freezes
- ~206
- NOAA 1991–2020 Climate Normals, 28°F — this town
- Town area
- 96 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 6a is Hartsburg's average, not your lot's — a low corner or a tree line moves it. Against Hartsburg's 206-day season, see what your own ground reads.
Soil varies lot by lot — soil types explained.
What this means for growing in Hartsburg
Each reading below is measured for Hartsburg itself — here is what it means for a garden here, and the move an experienced grower makes about it.
Season length
MeasuredHartsburg runs about 206 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
MeasuredHartsburg sits in USDA hardiness zone 6a.
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 Hartsburg is in
Hartsburg sits in the Central Corn Belt Plains — EPA Level III, inside the wider Eastern Temperate Forests. That is read at Hartsburg's own centroid rather than borrowed from Logan County.
What Grows in Hartsburg
Every plant below cleared Hartsburg's own zone 6a and its 206-day season. Each card opens that plant's Illinois profile. How we score.
Is it too late to plant in Hartsburg?
Usually not — gardeners here simply switch what goes in the ground as the season moves. Cool-season crops can go in from around Mar 8; tender transplants wait until two to three weeks after the last 28°F hard freeze, which lands near Apr 5 (NOAA 1991–2020 climate normals); and from midsummer, planting counts back from the first fall freeze around Oct 28 — long-season crops need about 90 days of runway, quick greens only 30. Here the season winds down slowly: late sowings, a real autumn harvest, and garlic in the ground before the first hard freeze.
What's on the federal record near Hartsburg
Closest first, within ~10 miles of Hartsburg. Listing isn't leaking, and distance isn't exposure.
- Hartsburg 40Underground Storage Tanks · 300 ft
- Ag Land Fd IncUnderground Storage Tanks · 500 ft
- Hartsburg AmocoUnderground Storage Tanks · 500 ft
- Gerald R. Lolling PropertyUnderground Storage Tanks · 650 ft
- HARTSBURG CUSD 21Brownfields · 800 ft
- Hartsburg-Emden School Dist #21Underground Storage Tanks · 800 ft
- 2000 N and 700 ENitrate · 3.2 mi
- GEBHART FERTILIZER COMPANYSuperfund · 3.5 mi
- Emden 40Underground Storage Tanks · 3.8 mi
- Heineken Bros BldgUnderground Storage Tanks · 3.9 mi
- Emden Service CenterUnderground Storage Tanks · 4.0 mi
- Fink Chevrolet Co IncUnderground Storage Tanks · 4.1 mi
6 more sites are on the record inside the same radius. See them on the map
Measured from Hartsburg'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 Hartsburg.
Total Sites
186
within ~10 miles of Hartsburg
Risk Level
Elevated
Highest-severity
2 Superfund sites (none NPL-listed)
Sources Checked
within ~10 miles of Hartsburg
Severity Distribution
within ~10 miles of Hartsburg
Highest-Severity Sites
A note from Gnorman
What an experienced grower watches for around here
In and around Hartsburg, two things run higher than the national average within ~10 miles of Hartsburg — CAFO (5 sites) and Underground Storage Tanks (115 sites). It's not cause for alarm — it's worth knowing, and there's a sensible way to grow around it.
CAFO: CAFOs pose a different contamination profile than chemical sources.
Underground Storage Tanks: Underground storage tanks are the single most common source of soil contamination near homes and gardens.
Wash all produce consumed raw thoroughly, especially leafy greens grown near CAFOs.
Use raised beds with imported soil — this eliminates the primary soil-contact pathway.
Check your specific parcel in Hartsburg
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 Hartsburg average
Your land is one point inside Hartsburg
Everything above resolves to Hartsburg as a whole — one PHZM band and one 28°F frost record, read across 96 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 Hartsburg Average
Hartsburg Average
- ●USDA Zones 6a, averaged across Hartsburg
- ●One soil character for all of Hartsburg
- ●Frost dates read at Hartsburg's scale: Apr 5 to Oct 28
YOUR Parcel
- ✓Your exact zone, not Hartsburg's 6a
- ✓Your SSURGO soil type & pH
- ✓Your sun exposure, cast in 3D
See MY Growing Report
Read your specific parcel in Hartsburg
Pull a site-specific report for your exact address in Hartsburg, Illinois — soil, sun, drainage, frost risk, and scored plant recommendations.
Three things about your lot that Hartsburg averages can't show:
We read public map data around Hartsburg — soil, climate, flood, and parcel records. How we handle your address.
25+ data sources read at your address, not the Hartsburg average
How we know this about Hartsburg
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 Hartsburg’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 Hartsburg
When does frost risk typically end in Hartsburg?
The last hard freeze (28°F) in Hartsburg typically lands around Apr 5, 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 26.
When is the first frost in Hartsburg?
The first hard freeze (28°F) in Hartsburg typically arrives around Oct 28, per NOAA 1991–2020 climate normals — the point tender summer crops finish. Lighter frosts run ahead of it, near Oct 14, so the watching starts about Sep 28 — about 206 days after the spring freeze cleared.
How long is the growing season in Hartsburg?
Measured between 28°F hard freezes, Hartsburg sees about 206 frost-free days — roughly Apr 5 through Oct 28, per NOAA 1991–2020 climate normals. Tender crops work a shorter one: nearer Apr 26 to Oct 14, about 171 days.
Is the soil safe to grow vegetables in Hartsburg?
The federal record around Hartsburg is a meaningful one — 186 documented sites, mostly Underground Storage Tanks entries (115), the nearest Underground Storage Tanks record under a tenth of a mile 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 Hartsburg?
From about Sep 28 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 28 (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 28. Hardy greens and roots shrug off light frost and sweeten after it — leave them in.
Everything above is measured at Hartsburg's scale — its 6a band and its 206-day season. Your yard writes its own version of Hartsburg'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 Hartsburg’s own scale
6 of the readings below were taken at Hartsburg's own scale — its own ~206-day season between 28°F freezes, the 96 acres it covers and 186 documented sites around it; 4 are borrowed from a wider read, named and linked below.
Measured here
- Hartsburg's own USDA hardiness band, zones 6aUSDA PHZM 2023
- Hartsburg's own 28°F hard-freeze dates, about Apr 5 and Oct 28 and the ~206-day span between themNOAA 1991–2020 Climate Normals
- 186 documented contamination sites on the federal record near Hartsburg, the closest Underground Storage Tanks record under a tenth of a mile out from the town centreFederal environmental registers
- Hartsburg's boundary and the 96 acres inside itUS Census TIGER/Line 2025
- Which of 1,086 plants clear zones 6a and a ~206-day seasonGrowable Ground crop-matching engine
- The ecoregion at Hartsburg's own centroid, the Central Corn Belt PlainsUS EPA Level III Ecoregions
Inherited from a wider read
- Soil character — no town-scale survey exists, so Hartsburg's 96 acres read through its county's SSURGO summaryfrom Logan County
- Growing-degree days and winter chill — measured county-wide only, so the county page carries themfrom Logan County
- The growing challenges every Illinois grower plans around — written at state scale, so they stay on the state guidefrom Illinois
- Butterfly and beetle records, and the farmland pesticide estimate — all published county-widefrom Logan County
What this page can’t tell you
- The soil pH, drainage, sun hours, and frost pockets on any one lot among Hartsburg's 96 acreswhy one lot differs from the next →
- Which side of Hartsburg you're on — a low spot frosts first and a south wall warms early, and one normal is being asked to speak for all 96 acresreading your own microclimate →
- How close that record sits to YOUR lot — the closest Underground Storage Tanks record under a tenth of a mile 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 Hartsburg-wide figureread your own land →
More in Illinois
Wider growing context
What grows across IllinoisHartsburg sits outside our named growing regions, so Illinois as a whole is its closest context here.
Nearby growing guides