Harcourt, Iowa, sits in USDA hardiness zone 5a — enough range to grow cool-season vegetables, hardy fruit, and warm-season crops that mature before the first hard frost.
A short list that earns its place here — cabbage, cranberry, lavender, and collard greens — with any one site's soil, sun, and drainage making the final cut.
Even in Harcourt, 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 Harcourt 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 Harcourt — soil, climate, flood, and parcel records. How we handle your address.
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Harcourt — the short answer
Harcourt, Iowa: USDA zone 5a, about 189 days between hard freezes, across 647 acres of city.
- USDA zone
- 5a
- USDA PHZM 2023
- Last hard freeze (28°F)
- Apr 15
- NOAA 1991–2020 Climate Normals, 28°F — this town
- First hard freeze (28°F)
- Oct 21
- NOAA 1991–2020 Climate Normals, 28°F — this town
- Days between freezes
- ~189
- NOAA 1991–2020 Climate Normals, 28°F — this town
- City area
- 647 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 5a is Harcourt's average, not your lot's — a low corner or a tree line moves it. Against Harcourt's 189-day season, see what your own ground reads.
Soil varies lot by lot — soil types explained.
What this means for growing in Harcourt
Each reading below is measured for Harcourt itself — here is what it means for a garden here, and the move an experienced grower makes about it.
Season length
MeasuredHarcourt runs about 189 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
MeasuredHarcourt sits in USDA hardiness zone 5a.
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 Harcourt is in
Harcourt sits in the Western Corn Belt Plains — EPA Level III, inside the wider Great Plains. That is read at Harcourt's own centroid rather than borrowed from Webster County.
What Grows in Harcourt
Every plant below cleared Harcourt's own zone 5a and its 189-day season. Each card opens that plant's Iowa profile. How we score.
Is it too late to plant in Harcourt?
Rarely: the season closes in stages, not all at once, and each stage has its crops. Cool-season crops can go in from around Mar 18; tender transplants wait until two to three weeks after the last 28°F hard freeze, which lands near Apr 15 (NOAA 1991–2020 climate normals); and from midsummer, planting counts back from the first fall freeze around Oct 21 — 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 Harcourt
Closest first, within ~10 miles of Harcourt. Listing isn't leaking, and distance isn't exposure.
- MAINTENANCE SHEDUnderground Storage Tanks · 1300 ft
- 086N29W13BACC 00870 1939Harcourt 1Nitrate · 1600 ft
- 086N29W13BACC 07307 1955Harcourt 1Nitrate · 1600 ft
- HARCOURT EQUIPMENTBrownfields · 2600 ft
- HARCOURT DXUnderground Storage Tanks · 0.6 mi
- 086N28W21ABA 03387 1948Nitrate · 3.3 mi
- HY-CAPACITY ENG & MFG INCBrownfields · 4.8 mi
- CITY OF DAYTONUnderground Storage Tanks · 5.2 mi
- 086N28W02CDD 03164 1947Nitrate · 5.2 mi
- CASEY''S GENERAL STORE 2515Underground Storage Tanks · 5.2 mi
- 086N28W14ADBA 05548 1952Dayton 3Nitrate · 5.2 mi
- GENE MOELLER OIL COUnderground Storage Tanks · 5.3 mi
6 more sites are on the record inside the same radius. See them on the map
Measured from Harcourt'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 Harcourt.
Total Sites
119
within ~10 miles of Harcourt
Risk Level
Moderate
Highest-severity
6 Toxics Release Inventory facilities
Sources Checked
within ~10 miles of Harcourt
Severity Distribution
within ~10 miles of Harcourt
Highest-Severity Sites
A note from Gnorman
What an experienced grower watches for around here
In and around Harcourt, Nitrate runs higher than the national average — 56 sites within ~10 miles of Harcourt. It's not cause for alarm — it's worth knowing, and there's a sensible way to grow around it.
Nitrate: Nitrate contamination primarily comes from agricultural fertilizer runoff and failing septic systems.
Test well water for nitrate if you rely on a private well for irrigation (EPA standard: 10 mg/L).
Check your specific parcel in Harcourt
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 Harcourt average
Your land is one point inside Harcourt
Everything above resolves to Harcourt as a whole — one PHZM band and one 28°F frost record, read across 647 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 Harcourt Average
Harcourt Average
- ●USDA Zones 5a, averaged across Harcourt
- ●One soil character for all of Harcourt
- ●Frost dates read at Harcourt's scale: Apr 15 to Oct 21
YOUR Parcel
- ✓Your exact zone, not Harcourt's 5a
- ✓Your SSURGO soil type & pH
- ✓Your sun exposure, cast in 3D
See MY Growing Report
Read your specific parcel in Harcourt
Pull a site-specific report for your exact address in Harcourt, Iowa — soil, sun, drainage, frost risk, and scored plant recommendations.
Three things about your lot that Harcourt averages can't show:
We read public map data around Harcourt — soil, climate, flood, and parcel records. How we handle your address.
25+ data sources read at your address, not the Harcourt average
How we know this about Harcourt
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 Harcourt’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 Harcourt
When does frost risk typically end in Harcourt?
The last hard freeze (28°F) in Harcourt typically lands around Apr 15, 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 6.
When is the first frost in Harcourt?
The first hard freeze (28°F) in Harcourt typically arrives around Oct 21, per NOAA 1991–2020 climate normals — the point tender summer crops finish. Lighter frosts run ahead of it, near Oct 7, so the watching starts about Sep 21 — about 189 days after the spring freeze cleared.
How long is the growing season in Harcourt?
Measured between 28°F hard freezes, Harcourt sees about 189 frost-free days — roughly Apr 15 through Oct 21, per NOAA 1991–2020 climate normals. Tender crops work a shorter one: nearer May 6 to Oct 7, about 154 days.
Is the soil safe to grow vegetables in Harcourt?
The federal record around Harcourt shows 119 documented sites, mostly Nitrate entries (56), the nearest Underground Storage Tanks record about 0.2 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 Harcourt?
From about Sep 21 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 21 (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 21. Hardy greens and roots shrug off light frost and sweeten after it — leave them in.
Everything above is measured at Harcourt's scale — its 5a band and its 189-day season. Your yard writes its own version of Harcourt'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 Harcourt’s own scale
6 of the readings below were taken at Harcourt's own scale — its own ~189-day season between 28°F freezes, the 647 acres it covers and 119 documented sites around it; 4 are borrowed from a wider read, named and linked below.
Measured here
- Harcourt's own USDA hardiness band, zones 5aUSDA PHZM 2023
- Harcourt's own 28°F hard-freeze dates, about Apr 15 and Oct 21 and the ~189-day span between themNOAA 1991–2020 Climate Normals
- 119 documented contamination sites on the federal record near Harcourt, the closest Underground Storage Tanks record about 0.2 miles out from the town centreFederal environmental registers
- Harcourt's boundary and the 647 acres inside itUS Census TIGER/Line 2025
- Which of 1,086 plants clear zones 5a and a ~189-day seasonGrowable Ground crop-matching engine
- The ecoregion at Harcourt's own centroid, the Western Corn Belt PlainsUS EPA Level III Ecoregions
Inherited from a wider read
- Soil character — no town-scale survey exists, so Harcourt's 647 acres read through its county's SSURGO summaryfrom Webster County
- Growing-degree days and winter chill — measured county-wide only, so the county page carries themfrom Webster 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 Webster County
What this page can’t tell you
- The soil pH, drainage, sun hours, and frost pockets on any one lot among Harcourt's 647 acreswhy one lot differs from the next →
- Which side of Harcourt you're on — a low spot frosts first and a south wall warms early, and one normal is being asked to speak for all 647 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 Harcourt-wide figureread your own land →
More in Iowa
Wider growing context
What grows across IowaHarcourt sits outside our named growing regions, so Iowa as a whole is its closest context here.