Dike, 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.
On paper, cabbage, cranberry, lavender, and collard greens all suit these conditions — on the ground, soil, sun, and drainage make the final call.
Even in Dike, 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 Dike 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 Dike — soil, climate, flood, and parcel records. How we handle your address.
No card required · your full report in seconds
Dike — the short answer
Dike, Iowa: USDA zone 5a, about 185 days between hard freezes, across 889 acres of city.
- USDA zone
- 5a
- USDA PHZM 2023
- Last hard freeze (28°F)
- Apr 16
- NOAA 1991–2020 Climate Normals, 28°F — this town
- First hard freeze (28°F)
- Oct 18
- NOAA 1991–2020 Climate Normals, 28°F — this town
- Days between freezes
- ~185
- NOAA 1991–2020 Climate Normals, 28°F — this town
- City area
- 889 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 Dike's average, not your lot's — a low corner or a tree line moves it. Against Dike's 185-day season, see what your own ground reads.
Soil varies lot by lot — soil types explained.
What this means for growing in Dike
Each reading below is measured for Dike itself — here is what it means for a garden here, and the move an experienced grower makes about it.
Season length
MeasuredDike runs about 185 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
MeasuredDike 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 Dike is in
Dike sits in the Western Corn Belt Plains — EPA Level III, inside the wider Great Plains. That is read at Dike's own centroid rather than borrowed from Grundy County.
What Grows in Dike
Every plant below cleared Dike's own zone 5a and its 185-day season. Each card opens that plant's Iowa profile. How we score.
Is it too late to plant in Dike?
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 19; tender transplants wait until two to three weeks after the last 28°F hard freeze, which lands near Apr 16 (NOAA 1991–2020 climate normals); and from midsummer, planting counts back from the first fall freeze around Oct 18 — long-season crops need about 90 days of runway, quick greens only 30. The tail of the season still works: sixty-day crops into late summer, quick greens after, garlic last of all.
What's on the federal record near Dike
Closest first, within ~10 miles of Dike. Listing isn't leaking, and distance isn't exposure.
- CLARKE COUNTY SECONDARY ROADSUnderground Storage Tanks · 750 ft
- EAST ERICKSEN FARMS INCUnderground Storage Tanks · 750 ft
- FARMERS COOPERATIVE COMPANYUnderground Storage Tanks · 1000 ft
- DIKE-NEW HARTFORD COMMUNITY HIGH SCHOOLBrownfields · 1500 ft
- 088N15W05BCB 1996NAWQA City of DikeNitrate · 1600 ft
- 088N15W05BBBD 1935Dike 1Nitrate · 2100 ft
- KWIK STAR #703Underground Storage Tanks · 2100 ft
- MARVS REPAIRBrownfields · 2200 ft
- 088N15W05BBBD 07401 1955Dike 2Nitrate · 2200 ft
- KOCHS 66Underground Storage Tanks · 2300 ft
- DELTA SPORT PRODUCTS LLCToxics Release Inventory · 2300 ft
- DELTA SPORT PRODUCTS LLCBrownfields · 2300 ft
6 more sites are on the record inside the same radius. See them on the map
Measured from Dike'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 Dike.
Total Sites
234
within ~10 miles of Dike
Risk Level
Elevated
Highest-severity
9 Toxics Release Inventory facilities
Sources Checked
within ~10 miles of Dike
Severity Distribution
within ~10 miles of Dike
Highest-Severity Sites
A note from Gnorman
What an experienced grower watches for around here
In and around Dike, Nitrate runs higher than the national average — 76 sites within ~10 miles of Dike. That's not a problem with your land — it's information about 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 Dike
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 Dike average
Your land is one point inside Dike
Everything above resolves to Dike as a whole — one PHZM band and one 28°F frost record, read across 889 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 Dike Average
Dike Average
- ●USDA Zones 5a, averaged across Dike
- ●One soil character for all of Dike
- ●Frost dates read at Dike's scale: Apr 16 to Oct 18
YOUR Parcel
- ✓Your exact zone, not Dike's 5a
- ✓Your SSURGO soil type & pH
- ✓Your sun exposure, cast in 3D
See MY Growing Report
Read your specific parcel in Dike
Pull a site-specific report for your exact address in Dike, Iowa — soil, sun, drainage, frost risk, and scored plant recommendations.
Three things about your lot that Dike averages can't show:
We read public map data around Dike — soil, climate, flood, and parcel records. How we handle your address.
25+ data sources read at your address, not the Dike average
How we know this about Dike
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 Dike’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 Dike
When does frost risk typically end in Dike?
The last hard freeze (28°F) in Dike typically lands around Apr 16, 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 7.
When is the first frost in Dike?
The first hard freeze (28°F) in Dike typically arrives around Oct 18, per NOAA 1991–2020 climate normals — the point tender summer crops finish. Lighter frosts run ahead of it, near Oct 4, so the watching starts about Sep 18 — about 185 days after the spring freeze cleared.
How long is the growing season in Dike?
Measured between 28°F hard freezes, Dike sees about 185 frost-free days — roughly Apr 16 through Oct 18, per NOAA 1991–2020 climate normals. Tender crops work a shorter one: nearer May 7 to Oct 4, about 150 days.
Is the soil safe to grow vegetables in Dike?
The federal record around Dike is a meaningful one — 234 documented sites, mostly Underground Storage Tanks entries (97), the nearest Underground Storage Tanks record about 0.1 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 Dike?
From about Sep 18 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 18 (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 18. Hardy greens and roots shrug off light frost and sweeten after it — leave them in.
Everything above is measured at Dike's scale — its 5a band and its 185-day season. Your yard writes its own version of Dike'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 Dike’s own scale
6 of the readings below were taken at Dike's own scale — its own ~185-day season between 28°F freezes, the 889 acres it covers and 234 documented sites around it; 4 are borrowed from a wider read, named and linked below.
Measured here
- Dike's own USDA hardiness band, zones 5aUSDA PHZM 2023
- Dike's own 28°F hard-freeze dates, about Apr 16 and Oct 18 and the ~185-day span between themNOAA 1991–2020 Climate Normals
- 234 documented contamination sites on the federal record near Dike, the closest Underground Storage Tanks record about 0.1 miles out from the town centreFederal environmental registers
- Dike's boundary and the 889 acres inside itUS Census TIGER/Line 2025
- Which of 1,086 plants clear zones 5a and a ~185-day seasonGrowable Ground crop-matching engine
- The ecoregion at Dike'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 Dike's 889 acres read through its county's SSURGO summaryfrom Grundy County
- Growing-degree days and winter chill — measured county-wide only, so the county page carries themfrom Grundy 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 Grundy County
What this page can’t tell you
- The soil pH, drainage, sun hours, and frost pockets on any one lot among Dike's 889 acreswhy one lot differs from the next →
- Which side of Dike you're on — a low spot frosts first and a south wall warms early, and one normal is being asked to speak for all 889 acresreading your own microclimate →
- How close that record sits to YOUR lot — the closest Underground Storage Tanks record about 0.1 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 Dike-wide figureread your own land →
More in Iowa
Wider growing context
What grows across IowaDike sits outside our named growing regions, so Iowa as a whole is its closest context here.
Nearby growing guides