Rock Falls, Wisconsin, sits in USDA hardiness zone 4b — enough range to grow cool-season vegetables, hardy fruit, and warm-season crops that mature before the first hard frost.
Growers here do well with cabbage, cranberry, turkish rocket, and collard greens — with the usual caveat that any single yard's soil, sun, and drainage cast the deciding vote.
Even in Rock Falls, 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 Rock Falls 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 Rock Falls — soil, climate, flood, and parcel records. How we handle your address.
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Rock Falls — the short answer
Rock Falls, Wisconsin: USDA zone 4b, about 178 days between hard freezes, across 413 acres of town.
- USDA zone
- 4b
- USDA PHZM 2023
- Last hard freeze (28°F)
- Apr 22
- NOAA 1991–2020 Climate Normals, 28°F — this town
- First hard freeze (28°F)
- Oct 17
- NOAA 1991–2020 Climate Normals, 28°F — this town
- Days between freezes
- ~178
- NOAA 1991–2020 Climate Normals, 28°F — this town
- Town area
- 413 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 Rock Falls's average, not your lot's — a low corner or a tree line moves it. Against Rock Falls's 178-day season, see what your own ground reads.
Soil varies lot by lot — soil types explained.
What this means for growing in Rock Falls
Each reading below is measured for Rock Falls itself — here is what it means for a garden here, and the move an experienced grower makes about it.
Season length
MeasuredRock Falls runs about 178 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
MeasuredRock Falls 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 Rock Falls is in
Rock Falls sits in the Driftless Area — EPA Level III, inside the wider Eastern Temperate Forests. That is read at Rock Falls's own centroid, and it is not what its county reads: Dunn County is mostly North Central Hardwood Forests. The wider page above you is answering a different question about different ground.
What Grows in Rock Falls
Every plant below cleared Rock Falls's own zone 4b and its 178-day season. Each card opens that plant's Wisconsin profile. How we score.
Is it too late to plant in Rock Falls?
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 25; tender transplants wait until two to three weeks after the last 28°F hard freeze, which lands near Apr 22 (NOAA 1991–2020 climate normals); and from midsummer, planting counts back from the first fall freeze around Oct 17 — 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 Rock Falls
Closest first, within ~10 miles of Rock Falls. Listing isn't leaking, and distance isn't exposure.
- Rock Falls Mill CoopUnderground Storage Tanks · 1100 ft
- DOHMS GROCERYUnderground Storage Tanks · 1200 ft
- DAYS GROCERY & LOCKERUnderground Storage Tanks · 1900 ft
- DAYS HARDWAREUnderground Storage Tanks · 2200 ft
- DU-26/11W/22-0139Nitrate · 2400 ft
- DU-26/11W/23-0082Nitrate · 2600 ft
- LLOYD PAPENFUSUnderground Storage Tanks · 0.6 mi
- DU-26/11W/23-0138Nitrate · 0.7 mi
- Rock Falls ServiceUnderground Storage Tanks · 1.1 mi
- BURGEY TRUCKING LLC.Brownfields · 1.4 mi
- Luers GroceryUnderground Storage Tanks · 2.7 mi
- C DAIRY WEST SITECAFO · 3.0 mi
6 more sites are on the record inside the same radius. See them on the map
Measured from Rock Falls'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 Rock Falls.
Total Sites
90
within ~10 miles of Rock Falls
Risk Level
Moderate
Highest-severity
1 Toxics Release Inventory facility
Sources Checked
within ~10 miles of Rock Falls
Severity Distribution
within ~10 miles of Rock Falls
Highest-Severity Sites
A note from Gnorman
What an experienced grower watches for around here
In and around Rock Falls, CAFO runs higher than the national average — 5 sites within ~10 miles of Rock Falls. Knowing it is half the work — and it's nothing a thoughtful grower can't plan for.
CAFO: CAFOs pose a different contamination profile than chemical sources.
Wash all produce consumed raw thoroughly, especially leafy greens grown near CAFOs.
Check your specific parcel in Rock Falls
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 Rock Falls average
Your land is one point inside Rock Falls
Everything above resolves to Rock Falls as a whole — one PHZM band and one 28°F frost record, read across 413 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 Rock Falls Average
Rock Falls Average
- ●USDA Zones 4b, averaged across Rock Falls
- ●One soil character for all of Rock Falls
- ●Frost dates read at Rock Falls's scale: Apr 22 to Oct 17
YOUR Parcel
- ✓Your exact zone, not Rock Falls's 4b
- ✓Your SSURGO soil type & pH
- ✓Your sun exposure, cast in 3D
See MY Growing Report
Read your specific parcel in Rock Falls
Pull a site-specific report for your exact address in Rock Falls, Wisconsin — soil, sun, drainage, frost risk, and scored plant recommendations.
Three things about your lot that Rock Falls averages can't show:
We read public map data around Rock Falls — soil, climate, flood, and parcel records. How we handle your address.
25+ data sources read at your address, not the Rock Falls average
How we know this about Rock Falls
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 Rock Falls’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 Rock Falls
When does frost risk typically end in Rock Falls?
The last hard freeze (28°F) in Rock Falls typically lands around Apr 22, 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 13.
When is the first frost in Rock Falls?
The first hard freeze (28°F) in Rock Falls typically arrives around Oct 17, per NOAA 1991–2020 climate normals — the point tender summer crops finish. Lighter frosts run ahead of it, near Oct 3, so the watching starts about Sep 17 — about 178 days after the spring freeze cleared.
How long is the growing season in Rock Falls?
Measured between 28°F hard freezes, Rock Falls sees about 178 frost-free days — roughly Apr 22 through Oct 17, per NOAA 1991–2020 climate normals. Tender crops work a shorter one: nearer May 13 to Oct 3, about 143 days.
Is the soil safe to grow vegetables in Rock Falls?
The federal record around Rock Falls shows 90 documented sites, mostly Underground Storage Tanks entries (41), 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 Rock Falls?
From about Sep 17 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 17 (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 17. Hardy greens and roots shrug off light frost and sweeten after it — leave them in.
Everything above is measured at Rock Falls's scale — its 4b band and its 178-day season. Your yard writes its own version of Rock Falls'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 Rock Falls’s own scale
6 of the readings below were taken at Rock Falls's own scale — its own ~178-day season between 28°F freezes, the 413 acres it covers and 90 documented sites around it; 4 are borrowed from a wider read, named and linked below.
Measured here
- Rock Falls's own USDA hardiness band, zones 4bUSDA PHZM 2023
- Rock Falls's own 28°F hard-freeze dates, about Apr 22 and Oct 17 and the ~178-day span between themNOAA 1991–2020 Climate Normals
- 90 documented contamination sites on the federal record near Rock Falls, the closest Underground Storage Tanks record about 0.2 miles out from the town centreFederal environmental registers
- Rock Falls's boundary and the 413 acres inside itUS Census TIGER/Line 2025
- Which of 1,086 plants clear zones 4b and a ~178-day seasonGrowable Ground crop-matching engine
- Rock Falls sits in the Driftless Area — not the ecoregion its county mostly readsUS EPA Level III Ecoregions
Inherited from a wider read
- Soil character — no town-scale survey exists, so Rock Falls's 413 acres read through its county's SSURGO summaryfrom Dunn County
- Growing-degree days and winter chill — measured county-wide only, so the county page carries themfrom Dunn County
- The growing challenges every Wisconsin grower plans around — written at state scale, so they stay on the state guidefrom Wisconsin
- Butterfly and beetle records, and the farmland pesticide estimate — all published county-widefrom Dunn County
What this page can’t tell you
- The soil pH, drainage, sun hours, and frost pockets on any one lot among Rock Falls's 413 acreswhy one lot differs from the next →
- Which side of Rock Falls you're on — a low spot frosts first and a south wall warms early, and one normal is being asked to speak for all 413 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 Rock Falls-wide figureread your own land →
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