Unity, Illinois, sits in USDA hardiness zone 7a — room for a real mix of vegetables, fruit, and perennials matched to the local frost calendar.
Growers here do well with cabbage, hazelnut, california poppy, and collard greens — with the usual caveat that any single yard's soil, sun, and drainage cast the deciding vote.
Even in Unity, 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 Unity 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 Unity — soil, climate, flood, and parcel records. How we handle your address.
No card required · your full report in seconds
Unity — the short answer
Unity, Illinois: USDA zone 7a, about 243 days between hard freezes, across 449 acres of town.
- USDA zone
- 7a
- USDA PHZM 2023
- Last hard freeze (28°F)
- Mar 18
- NOAA 1991–2020 Climate Normals, 28°F — this town
- First hard freeze (28°F)
- Nov 16
- NOAA 1991–2020 Climate Normals, 28°F — this town
- Days between freezes
- ~243
- NOAA 1991–2020 Climate Normals, 28°F — this town
- Town area
- 449 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 Unity's average, not your lot's — a low corner or a tree line moves it. Against Unity's 243-day season, see what your own ground reads.
Soil varies lot by lot — soil types explained.
What this means for growing in Unity
Each reading below is measured for Unity itself — here is what it means for a garden here, and the move an experienced grower makes about it.
Season length
MeasuredUnity runs about 243 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
MeasuredUnity 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 Unity is in
Unity sits in the Mississippi Alluvial Plain — EPA Level III, inside the wider Eastern Temperate Forests. That is read at Unity's own centroid, and it is not what its county reads: Alexander County is mostly Interior River Valleys and Hills. The wider page above you is answering a different question about different ground.
What Grows in Unity
Every plant below cleared Unity's own zone 7a and its 243-day season. Each card opens that plant's Illinois profile. How we score.
Is it too late to plant in Unity?
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 18; tender transplants wait until two to three weeks after the last 28°F hard freeze, which lands near Mar 18 (NOAA 1991–2020 climate normals); and from midsummer, planting counts back from the first fall freeze around Nov 16 — 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 Unity
Closest first, within ~10 miles of Unity. Listing isn't leaking, and distance isn't exposure.
- Pulaski/Sandusky Rd and IL-127Nitrate · 3.5 mi
- 16S 2W- 4.8bNitrate · 3.8 mi
- 2039958Underground Storage Tanks · 4.4 mi
- INTER-RAIL SYSTEMS INCBrownfields · 4.4 mi
- County Maint YardUnderground Storage Tanks · 4.5 mi
- Watson Oil Products IncUnderground Storage Tanks · 4.5 mi
- Ford Bruce & CliffordUnderground Storage Tanks · 4.5 mi
- Pulaski County Hwy DeptUnderground Storage Tanks · 4.5 mi
- Veach ServiceUnderground Storage Tanks · 4.6 mi
- Fill-Up MartUnderground Storage Tanks · 4.7 mi
- Watson JohnUnderground Storage Tanks · 4.7 mi
- Maintenance DeptUnderground Storage Tanks · 4.7 mi
6 more sites are on the record inside the same radius. See them on the map
Measured from Unity'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 Unity.
Total Sites
77
within ~10 miles of Unity
Risk Level
Moderate
Highest-severity
1 Toxics Release Inventory facility
Sources Checked
within ~10 miles of Unity
Severity Distribution
within ~10 miles of Unity
Highest-Severity Sites
A note from Gnorman
What an experienced grower watches for around here
In and around Unity, Underground Storage Tanks runs higher than the national average — 49 sites within ~10 miles of Unity. That's not a problem with your land — it's information about 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 Unity
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 Unity average
Your land is one point inside Unity
Everything above resolves to Unity as a whole — one PHZM band and one 28°F frost record, read across 449 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 Unity Average
Unity Average
- ●USDA Zones 7a, averaged across Unity
- ●One soil character for all of Unity
- ●Frost dates read at Unity's scale: Mar 18 to Nov 16
YOUR Parcel
- ✓Your exact zone, not Unity's 7a
- ✓Your SSURGO soil type & pH
- ✓Your sun exposure, cast in 3D
See MY Growing Report
Read your specific parcel in Unity
Pull a site-specific report for your exact address in Unity, Illinois — soil, sun, drainage, frost risk, and scored plant recommendations.
Three things about your lot that Unity averages can't show:
We read public map data around Unity — soil, climate, flood, and parcel records. How we handle your address.
25+ data sources read at your address, not the Unity average
How we know this about Unity
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 Unity’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 Unity
When does frost risk typically end in Unity?
The last hard freeze (28°F) in Unity typically lands around Mar 18, 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 8.
When is the first frost in Unity?
The first hard freeze (28°F) in Unity typically arrives around Nov 16, per NOAA 1991–2020 climate normals — the point tender summer crops finish. Lighter frosts run ahead of it, near Nov 2, so the watching starts about Oct 17 — about 243 days after the spring freeze cleared.
How long is the growing season in Unity?
Measured between 28°F hard freezes, Unity sees about 243 frost-free days — roughly Mar 18 through Nov 16, per NOAA 1991–2020 climate normals. Tender crops work a shorter one: nearer Apr 8 to Nov 2, about 208 days.
Is the soil safe to grow vegetables in Unity?
The federal record around Unity shows 77 documented sites, mostly Underground Storage Tanks entries (49), the nearest Nitrate record about 3.5 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 Unity?
From about Oct 17 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 16 (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 16. Hardy greens and roots shrug off light frost and sweeten after it — leave them in.
Everything above is measured at Unity's scale — its 7a band and its 243-day season. Your yard writes its own version of Unity'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 Unity’s own scale
6 of the readings below were taken at Unity's own scale — its own ~243-day season between 28°F freezes, the 449 acres it covers and 77 documented sites around it; 4 are borrowed from a wider read, named and linked below.
Measured here
- Unity's own USDA hardiness band, zones 7aUSDA PHZM 2023
- Unity's own 28°F hard-freeze dates, about Mar 18 and Nov 16 and the ~243-day span between themNOAA 1991–2020 Climate Normals
- 77 documented contamination sites on the federal record near Unity, the closest Nitrate record about 3.5 miles out from the town centreFederal environmental registers
- Unity's boundary and the 449 acres inside itUS Census TIGER/Line 2025
- Which of 1,086 plants clear zones 7a and a ~243-day seasonGrowable Ground crop-matching engine
- Unity sits in the Mississippi Alluvial Plain — not the ecoregion its county mostly readsUS EPA Level III Ecoregions
Inherited from a wider read
- Soil character — no town-scale survey exists, so Unity's 449 acres read through its county's SSURGO summaryfrom Alexander County
- Growing-degree days and winter chill — measured county-wide only, so the county page carries themfrom Alexander 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 Alexander County
What this page can’t tell you
- The soil pH, drainage, sun hours, and frost pockets on any one lot among Unity's 449 acreswhy one lot differs from the next →
- Which side of Unity you're on — a low spot frosts first and a south wall warms early, and one normal is being asked to speak for all 449 acresreading your own microclimate →
- How close that record sits to YOUR lot — the closest Nitrate record about 3.5 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 Unity-wide figureread your own land →