Rockford, Minnesota, sits in USDA hardiness zone 4b — room for a real mix of vegetables, fruit, and perennials matched to the local frost calendar.
Well-matched crops include cabbage, cranberry, turkish rocket, 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 Rockford, 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 Rockford 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 Rockford — soil, climate, flood, and parcel records. How we handle your address.
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Rockford — the short answer
Rockford, Minnesota: USDA zone 4b, about 185 days between hard freezes, across 2K acres of city.
- USDA zone
- 4b
- USDA PHZM 2023
- Last hard freeze (28°F)
- Apr 18
- NOAA 1991–2020 Climate Normals, 28°F — this town
- First hard freeze (28°F)
- Oct 20
- NOAA 1991–2020 Climate Normals, 28°F — this town
- Days between freezes
- ~185
- NOAA 1991–2020 Climate Normals, 28°F — this town
- City area
- 2K 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 4b is Rockford's average, not your lot's — a low corner or a tree line moves it. Against Rockford's 185-day season, see what your own ground reads.
Soil varies lot by lot — soil types explained.
What this means for growing in Rockford
Each reading below is measured for Rockford itself — here is what it means for a garden here, and the move an experienced grower makes about it.
Season length
MeasuredRockford 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
MeasuredRockford sits in USDA hardiness zone 4b.
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 Rockford is in
Rockford sits in the North Central Hardwood Forests — EPA Level III, inside the wider Eastern Temperate Forests. That is read at Rockford's own centroid rather than borrowed from Wright County.
What Grows in Rockford
Every plant below cleared Rockford's own zone 4b and its 185-day season. Each card opens that plant's Minnesota profile. How we score.
Is it too late to plant in Rockford?
Usually not — gardeners here simply switch what goes in the ground as the season moves. Cool-season crops can go in from around Mar 21; tender transplants wait until two to three weeks after the last 28°F hard freeze, which lands near Apr 18 (NOAA 1991–2020 climate normals); and from midsummer, planting counts back from the first fall freeze around Oct 20 — long-season crops need about 90 days of runway, quick greens only 30. As the window narrows, the plantings just get faster — fall brassicas, then greens, then garlic to finish.
What's on the federal record near Rockford
Closest first, within ~10 miles of Rockford. Listing isn't leaking, and distance isn't exposure.
- BRENNER FAMILY DENTALBrownfields · 600 ft
- Wright-Hennepin GenerationUnderground Storage Tanks · 750 ft
- DOLLAR GENERAL STORE 18158Brownfields · 900 ft
- COREY J BRENNER DDS PLLCBrownfields · 950 ft
- 119N24W29BAD 01 Rockford 1Nitrate · 1300 ft
- WRIGHT-HENNEPIN ELECTRIC COOPERATIVEBrownfields · 1500 ft
- ROCKFORD VETERINARY CLINICBrownfields · 2000 ft
- Riverside MotorsUnderground Storage Tanks · 2500 ft
- VERGIN SALESBrownfields · 0.5 mi
- HOLIDAY SALES INCBrownfields · 0.6 mi
- VER-TECH INCBrownfields · 0.6 mi
- ROCKFORD WWTPBrownfields · 0.7 mi
6 more sites are on the record inside the same radius. See them on the map
Measured from Rockford'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 Rockford.
Total Sites
604
within ~10 miles of Rockford
Risk Level
Elevated
Highest-severity
18 Toxics Release Inventory facilities
Sources Checked
within ~10 miles of Rockford
Severity Distribution
within ~10 miles of Rockford
Highest-Severity Sites
A note from Gnorman
What an experienced grower watches for around here
In and around Rockford, two things run higher than the national average within ~10 miles of Rockford — Brownfields (330 sites) and PFAS (5 sites). Knowing it is half the work — and it's nothing a thoughtful grower can't plan for.
Brownfields: Brownfield sites are former commercial or industrial properties where legacy soil contamination (heavy metals, PAHs, petroleum compounds) may persist.
PFAS: PFAS (per- and polyfluoroalkyl substances) are called "forever chemicals" because they do not biodegrade.
Check EPA brownfield remediation status — many sites have completed cleanup with institutional controls.
Test irrigation water source — this is the primary pathway for PFAS to reach garden crops.
Check your specific parcel in Rockford
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 Rockford average
Your land is one point inside Rockford
Everything above resolves to Rockford as a whole — one PHZM band and one 28°F frost record, read across 2K 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 Rockford Average
Rockford Average
- ●USDA Zones 4b, averaged across Rockford
- ●One soil character for all of Rockford
- ●Frost dates read at Rockford's scale: Apr 18 to Oct 20
YOUR Parcel
- ✓Your exact zone, not Rockford's 4b
- ✓Your SSURGO soil type & pH
- ✓Your sun exposure, cast in 3D
See MY Growing Report
Read your specific parcel in Rockford
Pull a site-specific report for your exact address in Rockford, Minnesota — soil, sun, drainage, frost risk, and scored plant recommendations.
Three things about your lot that Rockford averages can't show:
We read public map data around Rockford — soil, climate, flood, and parcel records. How we handle your address.
25+ data sources read at your address, not the Rockford average
How we know this about Rockford
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 Rockford’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 Rockford
When does frost risk typically end in Rockford?
The last hard freeze (28°F) in Rockford typically lands around Apr 18, 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 9.
When is the first frost in Rockford?
The first hard freeze (28°F) in Rockford typically arrives around Oct 20, per NOAA 1991–2020 climate normals — the point tender summer crops finish. Lighter frosts run ahead of it, near Oct 6, so the watching starts about Sep 20 — about 185 days after the spring freeze cleared.
How long is the growing season in Rockford?
Measured between 28°F hard freezes, Rockford sees about 185 frost-free days — roughly Apr 18 through Oct 20, per NOAA 1991–2020 climate normals. Tender crops work a shorter one: nearer May 9 to Oct 6, about 150 days.
Is the soil safe to grow vegetables in Rockford?
The federal record around Rockford is a meaningful one — 604 documented sites, mostly Brownfields entries (330), the nearest Brownfields 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 Rockford?
From about Sep 20 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 20 (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 20. Hardy greens and roots shrug off light frost and sweeten after it — leave them in.
Everything above is measured at Rockford's scale — its 4b band and its 185-day season. Your yard writes its own version of Rockford'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 Rockford’s own scale
6 of the readings below were taken at Rockford's own scale — its own ~185-day season between 28°F freezes, the 1,617 acres it covers and 604 documented sites around it; 4 are borrowed from a wider read, named and linked below.
Measured here
- Rockford's own USDA hardiness band, zones 4bUSDA PHZM 2023
- Rockford's own 28°F hard-freeze dates, about Apr 18 and Oct 20 and the ~185-day span between themNOAA 1991–2020 Climate Normals
- 604 documented contamination sites on the federal record near Rockford, the closest Brownfields record about 0.1 miles out from the town centreFederal environmental registers
- Rockford's boundary and the 1,617 acres inside itUS Census TIGER/Line 2025
- Which of 1,086 plants clear zones 4b and a ~185-day seasonGrowable Ground crop-matching engine
- The ecoregion at Rockford's own centroid, the North Central Hardwood ForestsUS EPA Level III Ecoregions
Inherited from a wider read
- Soil character — no town-scale survey exists, so Rockford's 1,617 acres read through its county's SSURGO summaryfrom Wright County
- Growing-degree days and winter chill — measured county-wide only, so the county page carries themfrom Wright County
- The growing challenges every Minnesota grower plans around — written at state scale, so they stay on the state guidefrom Minnesota
- Butterfly and beetle records, and the farmland pesticide estimate — all published county-widefrom Wright County
What this page can’t tell you
- The soil pH, drainage, sun hours, and frost pockets on any one lot among Rockford's 1,617 acreswhy one lot differs from the next →
- Which side of Rockford you're on — a low spot frosts first and a south wall warms early, and one normal is being asked to speak for all 1,617 acresreading your own microclimate →
- How close that record sits to YOUR lot — the closest Brownfields 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 Rockford-wide figureread your own land →
More in Minnesota
Wider growing context
What grows across MinnesotaRockford sits outside our named growing regions, so Minnesota as a whole is its closest context here.
Nearby growing guides