Cass, Indiana, sits in USDA hardiness zone 6a — enough range to grow cool-season vegetables, hardy fruit, and warm-season crops that mature before the first hard frost.
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 Cass, 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 Cass 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 Cass — soil, climate, flood, and parcel records. How we handle your address.
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Cass — the short answer
Cass, Indiana: USDA zone 6a, about 215 days between hard freezes, across 138 acres of town.
- USDA zone
- 6a
- USDA PHZM 2023
- Last hard freeze (28°F)
- Apr 2
- NOAA 1991–2020 Climate Normals, 28°F — this town
- First hard freeze (28°F)
- Nov 3
- NOAA 1991–2020 Climate Normals, 28°F — this town
- Days between freezes
- ~215
- NOAA 1991–2020 Climate Normals, 28°F — this town
- Town area
- 138 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 Cass's average, not your lot's — a low corner or a tree line moves it. Against Cass's 215-day season, see what your own ground reads.
Soil varies lot by lot — soil types explained.
What this means for growing in Cass
Each reading below is measured for Cass itself — here is what it means for a garden here, and the move an experienced grower makes about it.
Season length
MeasuredCass runs about 215 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
MeasuredCass 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 Cass is in
Cass sits in the Interior River Valleys and Hills — EPA Level III, inside the wider Eastern Temperate Forests. That is read at Cass's own centroid rather than borrowed from Sullivan County.
What Grows in Cass
Every plant below cleared Cass's own zone 6a and its 215-day season. Each card opens that plant's Indiana profile. How we score.
Is it too late to plant in Cass?
Usually not — gardeners here simply switch what goes in the ground as the season moves. Cool-season crops can go in from around Mar 5; tender transplants wait until two to three weeks after the last 28°F hard freeze, which lands near Apr 2 (NOAA 1991–2020 climate normals); and from midsummer, planting counts back from the first fall freeze around Nov 3 — 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.
Documented around Cass
Survey cells within 31 miles of Cass checked for spotted lanternfly, none carrying a detection — a surveyed negative, not an absence of looking. Nearest documented record 123 miles off. What to watch for.
What's on the federal record near Cass
Closest first, within ~10 miles of Cass. Listing isn't leaking, and distance isn't exposure.
- WC-45 DUGGER, IND.Nitrate · 0.7 mi
- CASEYS GENERAL STORE 1865Underground Storage Tanks · 1.3 mi
- KERNS SERVICE STATIONUnderground Storage Tanks · 1.3 mi
- FORMER SWAN SERVICE & TIREUnderground Storage Tanks · 1.4 mi
- Coal Mine CornerUnderground Storage Tanks · 1.6 mi
- COCA COLA BOTTLING COMPANYUnderground Storage Tanks · 1.6 mi
- DUGGER ELECTRICSuperfund · 1.7 mi
- DUGGER ELECTRICBrownfields · 1.7 mi
- Peabody Midwest Mining LLC North MineUnderground Storage Tanks · 1.8 mi
- SULLIVAN NORTHToxics Release Inventory · 1.9 mi
- MINNEHAHA TRAIN DERAILMENTSuperfund · 3.0 mi
- WC-39 NR. MIDLAND, INDIANANitrate · 4.5 mi
6 more sites are on the record inside the same radius. See them on the map
Measured from Cass'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 Cass.
Total Sites
119
within ~10 miles of Cass
Risk Level
Elevated
Highest-severity
3 Superfund sites (none NPL-listed)
Sources Checked
within ~10 miles of Cass
Severity Distribution
within ~10 miles of Cass
Highest-Severity Sites
A note from Gnorman
What an experienced grower watches for around here
In and around Cass, two things run higher than the national average within ~10 miles of Cass — PFAS (3 sites) and Superfund (3 sites). It's not cause for alarm — it's worth knowing, and there's a sensible way to grow around it.
PFAS: PFAS (per- and polyfluoroalkyl substances) are called "forever chemicals" because they do not biodegrade.
Superfund: Superfund sites represent the most severe contamination in the federal system.
Test irrigation water source — this is the primary pathway for PFAS to reach garden crops.
Commission professional soil testing before any food production (test for heavy metals, VOCs, and SVOCs).
Check your specific parcel in Cass
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 Cass average
Your land is one point inside Cass
Everything above resolves to Cass as a whole — one PHZM band and one 28°F frost record, read across 138 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 Cass Average
Cass Average
- ●USDA Zones 6a, averaged across Cass
- ●One soil character for all of Cass
- ●Frost dates read at Cass's scale: Apr 2 to Nov 3
YOUR Parcel
- ✓Your exact zone, not Cass's 6a
- ✓Your SSURGO soil type & pH
- ✓Your sun exposure, cast in 3D
See MY Growing Report
Read your specific parcel in Cass
Pull a site-specific report for your exact address in Cass, Indiana — soil, sun, drainage, frost risk, and scored plant recommendations.
Three things about your lot that Cass averages can't show:
We read public map data around Cass — soil, climate, flood, and parcel records. How we handle your address.
25+ data sources read at your address, not the Cass average
How we know this about Cass
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 Cass’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 Cass
When does frost risk typically end in Cass?
The last hard freeze (28°F) in Cass typically lands around Apr 2, 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 23.
When is the first frost in Cass?
The first hard freeze (28°F) in Cass typically arrives around Nov 3, per NOAA 1991–2020 climate normals — the point tender summer crops finish. Lighter frosts run ahead of it, near Oct 20, so the watching starts about Oct 4 — about 215 days after the spring freeze cleared.
How long is the growing season in Cass?
Measured between 28°F hard freezes, Cass sees about 215 frost-free days — roughly Apr 2 through Nov 3, per NOAA 1991–2020 climate normals. Tender crops work a shorter one: nearer Apr 23 to Oct 20, about 180 days.
Is the soil safe to grow vegetables in Cass?
The federal record around Cass is a meaningful one — 119 documented sites, mostly Underground Storage Tanks entries (73), the nearest Nitrate record about 0.7 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 Cass?
From about Oct 4 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 3 (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 3. Hardy greens and roots shrug off light frost and sweeten after it — leave them in.
Everything above is measured at Cass's scale — its 6a band and its 215-day season. Your yard writes its own version of Cass'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 Cass’s own scale
7 of the readings below were taken at Cass's own scale — its own ~215-day season between 28°F freezes, the 138 acres it covers and 119 documented sites around it; 4 are borrowed from a wider read, named and linked below.
Measured here
- Cass's own USDA hardiness band, zones 6aUSDA PHZM 2023
- Cass's own 28°F hard-freeze dates, about Apr 2 and Nov 3 and the ~215-day span between themNOAA 1991–2020 Climate Normals
- 119 documented contamination sites on the federal record near Cass, the closest Nitrate record about 0.7 miles out from the town centreFederal environmental registers
- Cass's boundary and the 138 acres inside itUS Census TIGER/Line 2025
- Which of 1,086 plants clear zones 6a and a ~215-day seasonGrowable Ground crop-matching engine
- The ecoregion at Cass's own centroid, the Interior River Valleys and HillsUS EPA Level III Ecoregions
- Lanternfly survey cells around Cass 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 Cass's 138 acres read through its county's SSURGO summaryfrom Sullivan County
- Growing-degree days and winter chill — measured county-wide only, so the county page carries themfrom Sullivan County
- The growing challenges every Indiana grower plans around — written at state scale, so they stay on the state guidefrom Indiana
- Butterfly and beetle records, and the farmland pesticide estimate — all published county-widefrom Sullivan County
What this page can’t tell you
- The soil pH, drainage, sun hours, and frost pockets on any one lot among Cass's 138 acreswhy one lot differs from the next →
- Which side of Cass you're on — a low spot frosts first and a south wall warms early, and one normal is being asked to speak for all 138 acresreading your own microclimate →
- How close that record sits to YOUR lot — the closest Nitrate record about 0.7 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 Cass-wide figureread your own land →
More in Indiana
Wider growing context
What grows across IndianaCass sits outside our named growing regions, so Indiana as a whole is its closest context here.
Nearby growing guides