Oswego, Indiana, sits in USDA hardiness zone 6a — room for a real mix of vegetables, fruit, and perennials matched to the local frost calendar.
Well-matched crops include cabbage, hazelnut, lavender, and collard greens, and the gap between "grows in the area" and "grows in your yard" is closed by soil, sun, and drainage.
Even in Oswego, 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 Oswego 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 Oswego — soil, climate, flood, and parcel records. How we handle your address.
No card required · your full report in seconds
Oswego — the short answer
Oswego, Indiana: USDA zone 6a, about 202 days between hard freezes, across 300 acres of town.
- USDA zone
- 6a
- USDA PHZM 2023
- Last hard freeze (28°F)
- Apr 13
- NOAA 1991–2020 Climate Normals, 28°F — this town
- First hard freeze (28°F)
- Nov 1
- NOAA 1991–2020 Climate Normals, 28°F — this town
- Days between freezes
- ~202
- NOAA 1991–2020 Climate Normals, 28°F — this town
- Town area
- 300 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 Oswego's average, not your lot's — a low corner or a tree line moves it. Against Oswego's 202-day season, see what your own ground reads.
Soil varies lot by lot — soil types explained.
What this means for growing in Oswego
Each reading below is measured for Oswego itself — here is what it means for a garden here, and the move an experienced grower makes about it.
Season length
MeasuredOswego runs about 202 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
MeasuredOswego 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 Oswego is in
Oswego sits in the Southern Michigan/Northern Indiana Drift Plains — EPA Level III, inside the wider Eastern Temperate Forests. That is read at Oswego's own centroid rather than borrowed from Kosciusko County.
What Grows in Oswego
Every plant below cleared Oswego's own zone 6a and its 202-day season. Each card opens that plant's Indiana profile. How we score.
Is it too late to plant in Oswego?
Almost never — the real question is what to plant next. Cool-season crops can go in from around Mar 16; tender transplants wait until two to three weeks after the last 28°F hard freeze, which lands near Apr 13 (NOAA 1991–2020 climate normals); and from midsummer, planting counts back from the first fall freeze around Nov 1 — long-season crops need about 90 days of runway, quick greens only 30. With a season this long, “too late” mostly means “switch crops” — second sowings and a full fall garden are the norm, with garlic closing the year.
Documented around Oswego
Spotted lanternfly documented 21 miles from Oswego, first recorded 2023. What to watch for.
What's on the federal record near Oswego
Closest first, within ~10 miles of Oswego. Listing isn't leaking, and distance isn't exposure.
- BUD VANSCOIKUnderground Storage Tanks · 900 ft
- TIPPY TACKLE & MINI MARTUnderground Storage Tanks · 1200 ft
- PATONA BAY BOAT SERVICEUnderground Storage Tanks · 0.9 mi
- 8248 - CHAPMAN LAKEBrownfields · 1.6 mi
- TIPPECANOE LAKES COUNTRY CLUBUnderground Storage Tanks · 1.6 mi
- PRECISION MARINAUnderground Storage Tanks · 1.8 mi
- Wabash Valley Produce IncorporatedUnderground Storage Tanks · 2.4 mi
- INDIANA CABINET COMPANY INCORPORATEDUnderground Storage Tanks · 2.4 mi
- CHAPMAN LAKE MARINAUnderground Storage Tanks · 2.8 mi
- DEWART LAKE MARINAUnderground Storage Tanks · 2.8 mi
- COMPOSITES DESIGNS INCORPORATEDToxics Release Inventory · 3.1 mi
- COMPOSITE DESIGNS INCORPORATEDToxics Release Inventory · 3.1 mi
6 more sites are on the record inside the same radius. See them on the map
Measured from Oswego'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 Oswego.
Total Sites
443
within ~10 miles of Oswego
Risk Level
Elevated
Highest-severity
3 Superfund sites (none NPL-listed)
Sources Checked
within ~10 miles of Oswego
Severity Distribution
within ~10 miles of Oswego
Highest-Severity Sites
A note from Gnorman
What an experienced grower watches for around here
In and around Oswego, Toxics Release Inventory runs higher than the national average — 65 sites within ~10 miles of Oswego. It's not cause for alarm — it's worth knowing, and there's a sensible way to grow around it.
Toxics Release Inventory: TRI facilities report annual chemical releases to air, water, and land.
Check prevailing wind direction — downwind parcels face higher exposure than upwind or crosswind locations.
Check your specific parcel in Oswego
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 Oswego average
Your land is one point inside Oswego
Everything above resolves to Oswego as a whole — one PHZM band and one 28°F frost record, read across 300 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 Oswego Average
Oswego Average
- ●USDA Zones 6a, averaged across Oswego
- ●One soil character for all of Oswego
- ●Frost dates read at Oswego's scale: Apr 13 to Nov 1
YOUR Parcel
- ✓Your exact zone, not Oswego's 6a
- ✓Your SSURGO soil type & pH
- ✓Your sun exposure, cast in 3D
See MY Growing Report
Read your specific parcel in Oswego
Pull a site-specific report for your exact address in Oswego, Indiana — soil, sun, drainage, frost risk, and scored plant recommendations.
Three things about your lot that Oswego averages can't show:
We read public map data around Oswego — soil, climate, flood, and parcel records. How we handle your address.
25+ data sources read at your address, not the Oswego average
How we know this about Oswego
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 Oswego’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 Oswego
When does frost risk typically end in Oswego?
The last hard freeze (28°F) in Oswego typically lands around Apr 13, 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 May 4.
When is the first frost in Oswego?
The first hard freeze (28°F) in Oswego typically arrives around Nov 1, per NOAA 1991–2020 climate normals — the point tender summer crops finish. Lighter frosts run ahead of it, near Oct 18, so the watching starts about Oct 2 — about 202 days after the spring freeze cleared.
How long is the growing season in Oswego?
Measured between 28°F hard freezes, Oswego sees about 202 frost-free days — roughly Apr 13 through Nov 1, per NOAA 1991–2020 climate normals. Tender crops work a shorter one: nearer May 4 to Oct 18, about 167 days.
Is the soil safe to grow vegetables in Oswego?
The federal record around Oswego is a meaningful one — 443 documented sites, mostly Underground Storage Tanks entries (250), the nearest Underground Storage Tanks record about 0.2 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 Oswego?
From about Oct 2 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 1 (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 1. Hardy greens and roots shrug off light frost and sweeten after it — leave them in.
Everything above is measured at Oswego's scale — its 6a band and its 202-day season. Your yard writes its own version of Oswego'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 Oswego’s own scale
7 of the readings below were taken at Oswego's own scale — its own ~202-day season between 28°F freezes, the 300 acres it covers and 443 documented sites around it; 4 are borrowed from a wider read, named and linked below.
Measured here
- Oswego's own USDA hardiness band, zones 6aUSDA PHZM 2023
- Oswego's own 28°F hard-freeze dates, about Apr 13 and Nov 1 and the ~202-day span between themNOAA 1991–2020 Climate Normals
- 443 documented contamination sites on the federal record near Oswego, the closest Underground Storage Tanks record about 0.2 miles out from the town centreFederal environmental registers
- Oswego's boundary and the 300 acres inside itUS Census TIGER/Line 2025
- Which of 1,086 plants clear zones 6a and a ~202-day seasonGrowable Ground crop-matching engine
- The ecoregion at Oswego's own centroid, the Southern Michigan/Northern Indiana Drift PlainsUS EPA Level III Ecoregions
- A documented spotted-lanternfly record within reach of Oswegolydemapr (De Bona & Helmus), 10 km survey lattice
Inherited from a wider read
- Soil character — no town-scale survey exists, so Oswego's 300 acres read through its county's SSURGO summaryfrom Kosciusko County
- Growing-degree days and winter chill — measured county-wide only, so the county page carries themfrom Kosciusko 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 Kosciusko County
What this page can’t tell you
- The soil pH, drainage, sun hours, and frost pockets on any one lot among Oswego's 300 acreswhy one lot differs from the next →
- Which side of Oswego you're on — a low spot frosts first and a south wall warms early, and one normal is being asked to speak for all 300 acresreading your own microclimate →
- How close that record sits to YOUR lot — the closest Underground Storage Tanks 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 Oswego-wide figureread your own land →
More in Indiana
Wider growing context
What grows across IndianaOswego sits outside our named growing regions, so Indiana as a whole is its closest context here.
Nearby growing guides