Merrillville, Indiana, sits in USDA hardiness zone 6a — a range where zone-matched perennials and frost-aware annual timing set what succeeds.
On paper, cabbage, hazelnut, lavender, and collard greens all suit these conditions — on the ground, soil, sun, and drainage make the final call.
Even in Merrillville, 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 Merrillville 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 Merrillville — soil, climate, flood, and parcel records. How we handle your address.
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Merrillville — the short answer
Merrillville, Indiana: USDA zone 6a, about 207 days between hard freezes, across 21K acres of town.
- USDA zone
- 6a
- USDA PHZM 2023
- Last hard freeze (28°F)
- Apr 10
- 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
- ~207
- NOAA 1991–2020 Climate Normals, 28°F — this town
- Town area
- 21K 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 Merrillville's average, not your lot's — a low corner or a tree line moves it. Against Merrillville's 207-day season, see what your own ground reads.
Soil varies lot by lot — soil types explained.
What this means for growing in Merrillville
Each reading below is measured for Merrillville itself — here is what it means for a garden here, and the move an experienced grower makes about it.
Season length
MeasuredMerrillville runs about 207 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
MeasuredMerrillville 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 Merrillville is in
Merrillville sits in the Central Corn Belt Plains — EPA Level III, inside the wider Eastern Temperate Forests. That is read at Merrillville's own centroid rather than borrowed from Lake County.
What Grows in Merrillville
Every plant below cleared Merrillville's own zone 6a and its 207-day season. Each card opens that plant's Indiana profile. How we score.
Is it too late to plant in Merrillville?
Usually not — gardeners here simply switch what goes in the ground as the season moves. Cool-season crops can go in from around Mar 13; tender transplants wait until two to three weeks after the last 28°F hard freeze, which lands near Apr 10 (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. A long window like this one runs successions deep into fall — and even its last weeks take quick greens and garlic.
Documented around Merrillville
Spotted lanternfly documented 17 miles from Merrillville, first recorded 2023. What to watch for.
What's on the federal record near Merrillville
Closest first, within ~10 miles of Merrillville. Listing isn't leaking, and distance isn't exposure.
- LOWE'S OF MERRILLVILLE, IN #1569Brownfields · 450 ft
- FORMER SUNOCO SERVICE STATIONUnderground Storage Tanks · 750 ft
- CARMAX #7180Brownfields · 800 ft
- Lukes 216Underground Storage Tanks · 850 ft
- Costco Wholesale 370Underground Storage Tanks · 1000 ft
- COSTCOBrownfields · 1000 ft
- TIRE BARNUnderground Storage Tanks · 1500 ft
- FIRESTONE STOREUnderground Storage Tanks · 1700 ft
- KIDDIE KANDIDS LLCBrownfields · 1700 ft
- PORTRAIT INNOVATIONSBrownfields · 1800 ft
- FIRESTONE STOREBrownfields · 1800 ft
- CVS PHARMACY 16307Brownfields · 2200 ft
6 more sites are on the record inside the same radius. See them on the map
Measured from Merrillville'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 Merrillville.
Sources Checked
within ~10 miles of Merrillville
Severity Distribution
within ~10 miles of Merrillville
Highest-Severity Sites
Know Before You Grow
- •Underground tanks leak petroleum as they age — near a former filling station, test the soil.
- •Near a brownfield, raised beds of imported soil give your food clean ground.
- •On a private well, test for nitrates: above 10 mg/L the water needs treatment before irrigating.
Check your specific parcel in Merrillville
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 Merrillville average
Your land is one point inside Merrillville
Everything above resolves to Merrillville as a whole — one PHZM band and one 28°F frost record, read across 21K 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 Merrillville Average
Merrillville Average
- ●USDA Zones 6a, averaged across Merrillville
- ●One soil character for all of Merrillville
- ●Frost dates read at Merrillville's scale: Apr 10 to Nov 3
YOUR Parcel
- ✓Your exact zone, not Merrillville's 6a
- ✓Your SSURGO soil type & pH
- ✓Your sun exposure, cast in 3D
See MY Growing Report
Read your specific parcel in Merrillville
Pull a site-specific report for your exact address in Merrillville, Indiana — soil, sun, drainage, frost risk, and scored plant recommendations.
Three things about your lot that Merrillville averages can't show:
We read public map data around Merrillville — soil, climate, flood, and parcel records. How we handle your address.
25+ data sources read at your address, not the Merrillville average
How we know this about Merrillville
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 Merrillville’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 Merrillville
When does frost risk typically end in Merrillville?
The last hard freeze (28°F) in Merrillville typically lands around Apr 10, 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 1.
When is the first frost in Merrillville?
The first hard freeze (28°F) in Merrillville 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 207 days after the spring freeze cleared.
How long is the growing season in Merrillville?
Measured between 28°F hard freezes, Merrillville sees about 207 frost-free days — roughly Apr 10 through Nov 3, per NOAA 1991–2020 climate normals. Tender crops work a shorter one: nearer May 1 to Oct 20, about 172 days.
Is the soil safe to grow vegetables in Merrillville?
The federal record around Merrillville runs heavier than most — 1,350 documented sites, mostly Underground Storage Tanks entries (735), the nearest Brownfields record under a tenth of a mile out — so test the soil before planting food in the ground, and raised beds with clean imported soil grow well in the meantime. Even here, proximity to a documented site is information, not a diagnosis of any one yard; the contamination map shows exactly what's recorded and where.
How do I protect my plants from frost in Merrillville?
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 Merrillville's scale — its 6a band and its 207-day season. Your yard writes its own version of Merrillville'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 Merrillville’s own scale
7 of the readings below were taken at Merrillville's own scale — its own ~207-day season between 28°F freezes, the 21,260 acres it covers and 1,350 documented sites around it; 4 are borrowed from a wider read, named and linked below.
Measured here
- Merrillville's own USDA hardiness band, zones 6aUSDA PHZM 2023
- Merrillville's own 28°F hard-freeze dates, about Apr 10 and Nov 3 and the ~207-day span between themNOAA 1991–2020 Climate Normals
- 1,350 documented contamination sites on the federal record near Merrillville, the closest Brownfields record under a tenth of a mile out from the town centreFederal environmental registers
- Merrillville's boundary and the 21,260 acres inside itUS Census TIGER/Line 2025
- Which of 1,086 plants clear zones 6a and a ~207-day seasonGrowable Ground crop-matching engine
- The ecoregion at Merrillville's own centroid, the Central Corn Belt PlainsUS EPA Level III Ecoregions
- A documented spotted-lanternfly record within reach of Merrillvillelydemapr (De Bona & Helmus), 10 km survey lattice
Inherited from a wider read
- Soil character — no town-scale survey exists, so Merrillville's 21,260 acres read through its county's SSURGO summaryfrom Lake County
- Growing-degree days and winter chill — measured county-wide only, so the county page carries themfrom Lake 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 Lake County
What this page can’t tell you
- The soil pH, drainage, sun hours, and frost pockets on any one lot among Merrillville's 21,260 acreswhy one lot differs from the next →
- Which side of Merrillville you're on — a low spot frosts first and a south wall warms early, and one normal is being asked to speak for all 21,260 acresreading your own microclimate →
- How close that record sits to YOUR lot — the closest Brownfields 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 Merrillville-wide figureread your own land →