Grand River, Iowa, sits in USDA hardiness zone 5b — room for a real mix of vegetables, fruit, and perennials matched to the local frost calendar.
Reliable performers under these conditions include cabbage, cranberry, lavender, and collard greens; what your own ground favors still comes down to its soil, sun, and drainage.
Even in Grand River, 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 River 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 River — soil, climate, flood, and parcel records. How we handle your address.
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Grand River — the short answer
Grand River, Iowa: USDA zone 5b, about 194 days between hard freezes, across 121 acres of city.
- USDA zone
- 5b
- USDA PHZM 2023
- Last hard freeze (28°F)
- Apr 11
- NOAA 1991–2020 Climate Normals, 28°F — this town
- First hard freeze (28°F)
- Oct 22
- NOAA 1991–2020 Climate Normals, 28°F — this town
- Days between freezes
- ~194
- NOAA 1991–2020 Climate Normals, 28°F — this town
- City area
- 121 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 5b is Grand River's average, not your lot's — a low corner or a tree line moves it. Against Grand River's 194-day season, see what your own ground reads.
Soil varies lot by lot — soil types explained.
What this means for growing in Grand River
Each reading below is measured for Grand River itself — here is what it means for a garden here, and the move an experienced grower makes about it.
Season length
MeasuredGrand River runs about 194 days between hard freezes — a moderate growing season.
There is room for the full run of cool-season crops plus a warm-season main crop, but the calendar is tight enough that a late spring or early fall frost still decides how much finishes.
Time warm-season transplants to your last hard freeze, and a few weeks of season extension turns a near-miss harvest into a sure one.
NOAA 1991–2020 Climate Normals
Winter hardiness
MeasuredGrand River sits in USDA hardiness zone 5b.
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 River is in
Grand River sits in the Central Irregular Plains — EPA Level III, inside the wider Great Plains. That is read at Grand River's own centroid rather than borrowed from Decatur County.
What Grows in Grand River
Every plant below cleared Grand River's own zone 5b and its 194-day season. Each card opens that plant's Iowa profile. How we score.
Is it too late to plant in Grand River?
Too late for some crops, right on time for others — a growing season is a sequence, not a deadline. Cool-season crops can go in from around Mar 14; tender transplants wait until two to three weeks after the last 28°F hard freeze, which lands near Apr 11 (NOAA 1991–2020 climate normals); and from midsummer, planting counts back from the first fall freeze around Oct 22 — long-season crops need about 90 days of runway, quick greens only 30. Even past midsummer there is room for a true fall garden here, and garlic planted near the close carries the momentum into next year.
What's on the federal record near Grand River
Closest first, within ~10 miles of Grand River. Listing isn't leaking, and distance isn't exposure.
- JIMMERSON SERVICEUnderground Storage Tanks · 250 ft
- GRAND RIVER OIL COMPANYUnderground Storage Tanks · 750 ft
- DEKALB QUARRYUnderground Storage Tanks · 750 ft
- MARTIN MARIETTA AGGREGATESUnderground Storage Tanks · 750 ft
- REASONERS GARAGE INCUnderground Storage Tanks · 4.6 mi
- SUN VALLEY MOTOR & MARINAUnderground Storage Tanks · 5.8 mi
- JOE FISHERCAFO · 7.0 mi
- 071N28W34DBBB 34560 1935CCC Camp 2Nitrate · 7.5 mi
- FORMER ELLSTON SERVICEUnderground Storage Tanks · 7.7 mi
- DECATUR CITY TEXACOUnderground Storage Tanks · 8.4 mi
- ABANDONED GAS STATIONUnderground Storage Tanks · 8.6 mi
- DECATUR QUARRYUnderground Storage Tanks · 8.6 mi
6 more sites are on the record inside the same radius. See them on the map
Measured from Grand River'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 River.
Total Sites
23
within ~10 miles of Grand River
Risk Level
Low
Highest-severity
1 concentrated animal feeding operation
Sources Checked
within ~10 miles of Grand River
Severity Distribution
within ~10 miles of Grand River
Highest-Severity Sites
Know Before You Grow
- •Underground tanks leak petroleum as they age — near a former filling station, test the soil.
- •On a private well, test for nitrates: above 10 mg/L the water needs treatment before irrigating.
- •Near a brownfield, raised beds of imported soil give your food clean ground.
Check your specific parcel in Grand River
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 River average
Your land is one point inside Grand River
Everything above resolves to Grand River as a whole — one PHZM band and one 28°F frost record, read across 121 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 River Average
Grand River Average
- ●USDA Zones 5b, averaged across Grand River
- ●One soil character for all of Grand River
- ●Frost dates read at Grand River's scale: Apr 11 to Oct 22
YOUR Parcel
- ✓Your exact zone, not Grand River's 5b
- ✓Your SSURGO soil type & pH
- ✓Your sun exposure, cast in 3D
See MY Growing Report
Read your specific parcel in Grand River
Pull a site-specific report for your exact address in Grand River, Iowa — soil, sun, drainage, frost risk, and scored plant recommendations.
Three things about your lot that Grand River averages can't show:
We read public map data around Grand River — soil, climate, flood, and parcel records. How we handle your address.
25+ data sources read at your address, not the Grand River average
How we know this about Grand River
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 River’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 River
When does frost risk typically end in Grand River?
The last hard freeze (28°F) in Grand River typically lands around Apr 11, 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 2.
When is the first frost in Grand River?
The first hard freeze (28°F) in Grand River typically arrives around Oct 22, per NOAA 1991–2020 climate normals — the point tender summer crops finish. Lighter frosts run ahead of it, near Oct 8, so the watching starts about Sep 22 — about 194 days after the spring freeze cleared.
How long is the growing season in Grand River?
Measured between 28°F hard freezes, Grand River sees about 194 frost-free days — roughly Apr 11 through Oct 22, per NOAA 1991–2020 climate normals. Tender crops work a shorter one: nearer May 2 to Oct 8, about 159 days.
Is the soil safe to grow vegetables in Grand River?
The federal record around Grand River is light — 23 documented sites across the 9 federal source types we checked, mostly Underground Storage Tanks entries (15), the nearest Underground Storage Tanks record under a tenth of a mile out — and proximity to a documented site is information, not a diagnosis of any one yard. Growing food here starts from a strong position; a soil test before new food beds settles any site-specific question.
How do I protect my plants from frost in Grand River?
From about Sep 22 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 Oct 22 (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 Oct 22. Hardy greens and roots shrug off light frost and sweeten after it — leave them in.
Everything above is measured at Grand River's scale — its 5b band and its 194-day season. Your yard writes its own version of Grand River'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 River’s own scale
6 of the readings below were taken at Grand River's own scale — its own ~194-day season between 28°F freezes, the 121 acres it covers and 23 documented sites around it; 4 are borrowed from a wider read, named and linked below.
Measured here
- Grand River's own USDA hardiness band, zones 5bUSDA PHZM 2023
- Grand River's own 28°F hard-freeze dates, about Apr 11 and Oct 22 and the ~194-day span between themNOAA 1991–2020 Climate Normals
- 23 documented contamination sites on the federal record near Grand River, the closest Underground Storage Tanks record under a tenth of a mile out from the town centreFederal environmental registers
- Grand River's boundary and the 121 acres inside itUS Census TIGER/Line 2025
- Which of 1,086 plants clear zones 5b and a ~194-day seasonGrowable Ground crop-matching engine
- The ecoregion at Grand River's own centroid, the Central Irregular PlainsUS EPA Level III Ecoregions
Inherited from a wider read
- Soil character — no town-scale survey exists, so Grand River's 121 acres read through its county's SSURGO summaryfrom Decatur County
- Growing-degree days and winter chill — measured county-wide only, so the county page carries themfrom Decatur County
- The growing challenges every Iowa grower plans around — written at state scale, so they stay on the state guidefrom Iowa
- Butterfly and beetle records, and the farmland pesticide estimate — all published county-widefrom Decatur County
What this page can’t tell you
- The soil pH, drainage, sun hours, and frost pockets on any one lot among Grand River's 121 acreswhy one lot differs from the next →
- Which side of Grand River you're on — a low spot frosts first and a south wall warms early, and one normal is being asked to speak for all 121 acresreading your own microclimate →
- How close that record sits to YOUR lot — the closest Underground Storage Tanks 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 Grand River-wide figureread your own land →
More in Iowa
Wider growing context
What grows across IowaGrand River sits outside our named growing regions, so Iowa as a whole is its closest context here.
Nearby growing guides