Grand Tower, Illinois, sits in USDA hardiness zone 7a — a zone band wide enough that plant choice, not possibility, is the interesting question.
The conditions favor cabbage, hazelnut, california poppy, and collard greens, among others — though every individual site edits that list with its own soil, sun, and drainage.
Even in Grand Tower, 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 Grand Tower 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 Grand Tower — soil, climate, flood, and parcel records. How we handle your address.
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Grand Tower — the short answer
Grand Tower, Illinois: USDA zone 7a, about 233 days between hard freezes, across 799 acres of city.
- USDA zone
- 7a
- USDA PHZM 2023
- Last hard freeze (28°F)
- Mar 22
- NOAA 1991–2020 Climate Normals, 28°F — this town
- First hard freeze (28°F)
- Nov 10
- NOAA 1991–2020 Climate Normals, 28°F — this town
- Days between freezes
- ~233
- NOAA 1991–2020 Climate Normals, 28°F — this town
- City area
- 799 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 7a is Grand Tower's average, not your lot's — a low corner or a tree line moves it. Against Grand Tower's 233-day season, see what your own ground reads.
Soil varies lot by lot — soil types explained.
What this means for growing in Grand Tower
Each reading below is measured for Grand Tower itself — here is what it means for a garden here, and the move an experienced grower makes about it.
Season length
MeasuredGrand Tower runs about 233 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
MeasuredGrand Tower sits in USDA hardiness zone 7a.
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 Grand Tower is in
Grand Tower sits in the Interior River Valleys and Hills — EPA Level III, inside the wider Eastern Temperate Forests. That is read at Grand Tower's own centroid rather than borrowed from Jackson County.
What Grows in Grand Tower
Every plant below cleared Grand Tower's own zone 7a and its 233-day season. Each card opens that plant's Illinois profile. How we score.
Is it too late to plant in Grand Tower?
Usually not — gardeners here simply switch what goes in the ground as the season moves. Cool-season crops can go in from around Feb 22; tender transplants wait until two to three weeks after the last 28°F hard freeze, which lands near Mar 22 (NOAA 1991–2020 climate normals); and from midsummer, planting counts back from the first fall freeze around Nov 10 — 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.
What's on the federal record near Grand Tower
Closest first, within ~10 miles of Grand Tower. Listing isn't leaking, and distance isn't exposure.
- Grand Tower Power StationUnderground Storage Tanks · 1.0 mi
- AMEREN - GRAND TOWER POWER STATIONToxics Release Inventory · 1.1 mi
- AMEREN - GRAND TOWER POWER STATIONBrownfields · 1.1 mi
- Cardinal CornerUnderground Storage Tanks · 1.2 mi
- EAST PERRY LUMBER COMPANYUnderground Storage Tanks · 1.5 mi
- Minor Lead Occurence No. 1Mining · 1.5 mi
- White Rose CafeUnderground Storage Tanks · 1.9 mi
- Veach Oil CompanyUnderground Storage Tanks · 2.8 mi
- MIDWEST AUTO PARTSUnderground Storage Tanks · 3.3 mi
- UnknownMining · 4.4 mi
- PETE'S PLACEUnderground Storage Tanks · 4.6 mi
- BELLMAN'S HARDWARE STOREUnderground Storage Tanks · 4.7 mi
6 more sites are on the record inside the same radius. See them on the map
Measured from Grand Tower'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 Grand Tower.
Total Sites
53
within ~10 miles of Grand Tower
Risk Level
Moderate
Highest-severity
2 Toxics Release Inventory facilities
Sources Checked
within ~10 miles of Grand Tower
Severity Distribution
within ~10 miles of Grand Tower
Highest-Severity Sites
A note from Gnorman
What an experienced grower watches for around here
In and around Grand Tower, Mining runs higher than the national average — 6 sites within ~10 miles of Grand Tower. That's not a problem with your land — it's information about it.
Mining: Mining sites — both historic and active — can leach heavy metals (arsenic, lead, cadmium, mercury) into soil and water for centuries after operations cease.
Test soil for heavy metals (lead, arsenic, cadmium, mercury) — this is essential near any mining site.
Check your specific parcel in Grand Tower
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 Grand Tower average
Your land is one point inside Grand Tower
Everything above resolves to Grand Tower as a whole — one PHZM band and one 28°F frost record, read across 799 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 Grand Tower Average
Grand Tower Average
- ●USDA Zones 7a, averaged across Grand Tower
- ●One soil character for all of Grand Tower
- ●Frost dates read at Grand Tower's scale: Mar 22 to Nov 10
YOUR Parcel
- ✓Your exact zone, not Grand Tower's 7a
- ✓Your SSURGO soil type & pH
- ✓Your sun exposure, cast in 3D
See MY Growing Report
Read your specific parcel in Grand Tower
Pull a site-specific report for your exact address in Grand Tower, Illinois — soil, sun, drainage, frost risk, and scored plant recommendations.
Three things about your lot that Grand Tower averages can't show:
We read public map data around Grand Tower — soil, climate, flood, and parcel records. How we handle your address.
25+ data sources read at your address, not the Grand Tower average
How we know this about Grand Tower
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 Grand Tower’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 Grand Tower
When does frost risk typically end in Grand Tower?
The last hard freeze (28°F) in Grand Tower typically lands around Mar 22, 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 12.
When is the first frost in Grand Tower?
The first hard freeze (28°F) in Grand Tower typically arrives around Nov 10, per NOAA 1991–2020 climate normals — the point tender summer crops finish. Lighter frosts run ahead of it, near Oct 27, so the watching starts about Oct 11 — about 233 days after the spring freeze cleared.
How long is the growing season in Grand Tower?
Measured between 28°F hard freezes, Grand Tower sees about 233 frost-free days — roughly Mar 22 through Nov 10, per NOAA 1991–2020 climate normals. Tender crops work a shorter one: nearer Apr 12 to Oct 27, about 198 days.
Is the soil safe to grow vegetables in Grand Tower?
The federal record around Grand Tower shows 53 documented sites, mostly Underground Storage Tanks entries (23), the nearest Underground Storage Tanks record about 1.0 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 Grand Tower?
From about Oct 11 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 10 (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 10. Hardy greens and roots shrug off light frost and sweeten after it — leave them in.
Everything above is measured at Grand Tower's scale — its 7a band and its 233-day season. Your yard writes its own version of Grand Tower'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 Grand Tower’s own scale
6 of the readings below were taken at Grand Tower's own scale — its own ~233-day season between 28°F freezes, the 799 acres it covers and 53 documented sites around it; 4 are borrowed from a wider read, named and linked below.
Measured here
- Grand Tower's own USDA hardiness band, zones 7aUSDA PHZM 2023
- Grand Tower's own 28°F hard-freeze dates, about Mar 22 and Nov 10 and the ~233-day span between themNOAA 1991–2020 Climate Normals
- 53 documented contamination sites on the federal record near Grand Tower, the closest Underground Storage Tanks record about 1.0 miles out from the town centreFederal environmental registers
- Grand Tower's boundary and the 799 acres inside itUS Census TIGER/Line 2025
- Which of 1,086 plants clear zones 7a and a ~233-day seasonGrowable Ground crop-matching engine
- The ecoregion at Grand Tower'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 Grand Tower's 799 acres read through its county's SSURGO summaryfrom Jackson County
- Growing-degree days and winter chill — measured county-wide only, so the county page carries themfrom Jackson 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 Jackson County
What this page can’t tell you
- The soil pH, drainage, sun hours, and frost pockets on any one lot among Grand Tower's 799 acreswhy one lot differs from the next →
- Which side of Grand Tower you're on — a low spot frosts first and a south wall warms early, and one normal is being asked to speak for all 799 acresreading your own microclimate →
- How close that record sits to YOUR lot — the closest Underground Storage Tanks record about 1.0 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 Grand Tower-wide figureread your own land →