Milwaukee County, in Wisconsin, sits in USDA hardiness zone 6a — a band that supports both cool-season staples and warm-season crops chosen to fit the local frost window.
Expect cabbage, hazelnut, lavender, and collard greens to be strong candidates here; the deciding factors on any one parcel stay local — soil, sun, and drainage.
Milwaukee County lies within the Southeastern Wisconsin Lakeshore (Milwaukee Metro) — a regional growing area with its own character.
Grounded in USDA PHZM 2023 · Growable Ground suitability scoring · NOAA 1991–2020 Climate Normals
Milwaukee County holds more than one microclimate.
Soils and elevations shift across Milwaukee County, so your frost dates and drainage aren't the county average. 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 Milwaukee County — soil, climate, flood, and parcel records. How we handle your address.
No card required · your full report in seconds
Milwaukee County — the short answer
Milwaukee County, Wisconsin: USDA zone 6a, about 217 days between hard freezes, across 155K acres.
- USDA zone
- 6a
- USDA PHZM 2023
- Last hard freeze (28°F)
- Apr 5
- NOAA 1991–2020 Climate Normals, 28°F
- First hard freeze (28°F)
- Nov 8
- NOAA 1991–2020 Climate Normals, 28°F
- Days between freezes
- ~217
- NOAA 1991–2020 Climate Normals, 28°F
- County area
- 155K acres
- US Census TIGER/Line 2025
Every figure names the dataset it came from. Hard-freeze dates are county 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 6a is Milwaukee County's average, not your lot's — a low corner or a tree line moves it. Against Milwaukee County's 217-day season, see what your own ground reads.
Heat in Milwaukee County
Across a year, Milwaukee County accumulates about 2,494 growing degree days above 50°F, about 344 more than the middle Wisconsin county — ahead of 67 of Wisconsin’s 72 counties. Degree days are the heat a crop actually gets to work with — more of them is more room to ripen a long-season crop before the freeze closes the window.
Grounded in PRISM Climate Group, Oregon State University — 1991–2020 monthly normals
Soil in Milwaukee County
Across Milwaukee County, the ground is predominantly Alfisols, where Ozaukee, Blount, and Mequon are the most extensive named soil series. The soil is generally moderately well drained with a silt loam surface. Topsoil pH runs about 6.2–7.0, neutral. Rainfall drains through hydrologic group C soils.
Soil order
Alfisols
Drainage
Moderately well drained
Prime farmland
27%
Hydric soils
11%
Soil still varies lot by lot — soil types explained.
How the ground varies across Milwaukee County
The USDA soil survey maps 26% of Milwaukee County as moderately well drained — but another 31% drains differently: 19% somewhat poorly drained, 6% well drained.
Ozaukee is the most extensive named soil at 46% of mapped acres, then Blount (12%) and Mequon (11%).
Which of them your own lot sits on is a parcel question, not a county one. Check your address for the survey at your boundary.
What this means for growing in Milwaukee County
Each reading below is measured for Milwaukee County itself — here is what it means for a garden here, and the move an experienced grower makes about it.
Drainage
MeasuredThe dominant soils across Milwaukee County are moderately well drained, in hydrologic group C — roughly the middle of the drainage range.
This is close to the middle most vegetables prefer: it holds enough water to carry a crop between rains without staying waterlogged. The catch is that a wet spring or a low corner can still tip it soggy.
Plant on the site as-is for most crops, but keep the lowest, slowest-draining beds for moisture-tolerant plantings.
USDA NRCS SSURGO
Surface pH
MeasuredTopsoil across Milwaukee County runs about pH 6.2–7.0, close to neutral.
This is the range most vegetables prefer — one correction you probably do not have to make, which is genuinely good news for a new bed.
Keep it there with compost rather than lime or sulfur, and only amend if your own soil test says otherwise.
USDA NRCS SSURGO
Season length
MeasuredMilwaukee County runs about 217 days between hard freezes — a long growing season.
There is slack for succession plantings and slow-finishing crops: many vegetables can be sown twice, and the heat-lovers have time to ripen fully.
Plan a second sowing of quick crops after the first comes out, and use the fall window most gardeners let sit idle.
NOAA 1991–2020 Climate Normals
Winter hardiness
MeasuredMilwaukee County sits in USDA hardiness zone 6a.
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 Milwaukee County is in
Milwaukee County sits in the Southeastern Wisconsin Till Plains — EPA Level III, inside the wider Eastern Temperate Forests. One consistent ecological setting across the whole county.
What Grows in Milwaukee County
We scored all 1,086 plants against Milwaukee County's own USDA zone 6a and its own 217-day season between hard freezes, using the same matching engine that runs a full parcel report. These cleared both. Sun, soil pH and drainage vary lot by lot — those are the parcel questions below. Each card opens that plant's Wisconsin profile.
Is it too late to plant in Milwaukee County?
Usually not — gardeners here simply switch what goes in the ground as the season moves. Cool-season crops can go in from around Mar 8; tender transplants wait until two to three weeks after the last 28°F hard freeze, which lands near Apr 5 (NOAA 1991–2020 climate normals); and from midsummer, planting counts back from the first fall freeze around Nov 8 — long-season crops need about 90 days of runway, quick greens only 30. With a season this long, “too late” mostly means “switch crops” — second sowings and a full fall garden are the norm, with garlic closing the year.
Documented around Milwaukee County
- Japanese beetle30 documented records
- monarch butterfly380 documented records
Sighting records, so they follow observers as much as insects.
What gets applied to farmland in Milwaukee County
USGS estimates 4,405 lb of Glyphosate on Milwaukee County farmland in 2019, its largest by weight, ahead of Metolachlor & Metolachlor-s (1,854 lb) and Metolachlor-s (1,643 lb).
Farmland across the whole county, not any one lot. Check your address for the site-by-site record.
Safe to Grow Here?
What the federal record shows across Milwaukee County — and how to grow with it.
We checked the federal record across Milwaukee County — 5,747 documented sites across 6 of the 9 source types we track.
The most significant on record: 50 Superfund sites. Sites tracked in EPA's Superfund program — from assessment-stage CERCLIS entries to confirmed National Priorities List cleanup sites.
There's a meaningful federal record across Milwaukee County — worth a look before you plant food, not a reason to hold back from growing. Proximity to a documented site is information, not a diagnosis of any one yard. A soil test before new food beds is the sensible precaution here, and the map shows exactly which sites sit where, so you can see what's actually near you.
Sources: EPA, USGS — 1.8M documented sites tracked nationwide across 9 federal source types.
What's on the federal record near Milwaukee County
Closest first, across Milwaukee County. Listing isn't leaking, and distance isn't exposure.
- SUNSHINE GASUnderground Storage Tanks · 600 ft
- Citgo #4248Underground Storage Tanks · 600 ft
- Bucyrus Erie InternationalUnderground Storage Tanks · 650 ft
- CATERPILLAR GLOBAL MININGToxics Release Inventory · 700 ft
- CATERPILLAR GLOBAL MININGSuperfund · 700 ft
- STEELE SOLUTIONS INCToxics Release Inventory · 700 ft
- LAST PROPERTYUnderground Storage Tanks · 700 ft
- SUNBRITE CLEANERSBrownfields · 700 ft
- SOUTH MILWAUKEE WATERWORKSPFAS · 750 ft
- CATERPILLAR GLOBAL MINING-NORTH OF RAWSONBrownfields · 950 ft
- CATERPILLAR GLOBAL MINING - NORTH OF RAWSONToxics Release Inventory · 950 ft
- Madison ArchivesUnderground Storage Tanks · 1000 ft
6 more sites are on the record inside the same radius. See them on the map
Measured from Milwaukee County'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 Milwaukee County.
Sources Checked
across Milwaukee County
Severity Distribution
across Milwaukee County
Highest-Severity Sites
A note from Gnorman
What an experienced grower watches for around here
In and around Milwaukee County, Toxics Release Inventory runs higher than the national average — 374 sites across Milwaukee County. It's not cause for alarm — it's worth knowing, and there's a sensible way to grow around it.
Toxics Release Inventory: TRI facilities report annual chemical releases to air, water, and land.
Check prevailing wind direction — downwind parcels face higher exposure than upwind or crosswind locations.
Check your specific parcel in Milwaukee County
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 Milwaukee County average
Your land is one point inside Milwaukee County
Everything above resolves to Milwaukee County as a whole — one PHZM band and one county frost record, read across 155K 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 county 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 county average.
Your Lot vs the Milwaukee County Average
Milwaukee County Average
- ●USDA Zones 6a, averaged across Milwaukee County
- ●One soil character for all of Milwaukee County
- ●Frost dates read at Milwaukee County's scale: Apr 5 to Nov 8
YOUR Parcel
- ✓Your exact zone, not Milwaukee County's 6a
- ✓Your SSURGO soil type & pH
- ✓Your sun exposure, cast in 3D
See MY Growing Report
Read your parcel in Milwaukee County
Pull a site-specific report for your exact address in Milwaukee County, Wisconsin — soil, sun, drainage, frost risk, and scored plant recommendations.
Three things about your lot that Milwaukee County averages can't show:
We read public map data around Milwaukee County — soil, climate, flood, and parcel records. How we handle your address.
25+ data sources read at your address, not the Milwaukee County average
How we know this about Milwaukee County
The datasets: hardiness from the USDA ARS Plant Hardiness Zone Map 2023, read at county grain; hard-freeze dates from NOAA 1991–2020 28°F normals at this county’s own record where one resolves, and the labelled statewide window where none does; soils from the USDA NRCS SSURGO survey, area-weighted across the county’s own map units; boundaries and acreage from US Census TIGER/Line 2025; the contamination and pesticide records from the federal sources named in their beats above. Where Milwaukee County carries no record of its own, the figure is inherited and labelled — the resolution ledger below names each.
Common questions about Milwaukee County
When does frost risk typically end in Milwaukee County?
The last hard freeze (28°F) in Milwaukee County typically lands around Apr 5, 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 Apr 26.
How long is the growing season in Milwaukee County?
Measured between 28°F hard freezes, Milwaukee County sees about 217 frost-free days — roughly Apr 5 through Nov 8, per NOAA 1991–2020 climate normals. Tender crops work a shorter one: nearer Apr 26 to Oct 25, about 182 days.
Is the soil safe to grow vegetables in Milwaukee County?
The federal record around Milwaukee County is a meaningful one — 5,747 documented sites, mostly Underground Storage Tanks entries (2,930), 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.
Everything above is measured at Milwaukee County's scale — its 6a band and its 217-day season. Your yard writes its own version of Milwaukee County's numbers: we read soil, sun, drainage and frost at your exact address. Try it for 14 days — no card required.
Will It Grow Here?
Zone fit is the first question — each answer below reads Wisconsin's frost window, season length, and soil profile against the plant's real requirements.
What this page reads at Milwaukee County’s own scale
9 of the readings below were taken at Milwaukee County's own scale — its own ~217-day span between 28°F freezes, the 3 most extensive soil series mapped here and 5,747 documented sites inside its boundary; one is borrowed from a wider read, named and linked below.
Measured here
- Milwaukee County's own USDA hardiness band, zones 6aUSDA PHZM 2023
- Milwaukee County's own 28°F hard-freeze dates and its ~217-day span between themNOAA 1991–2020 Climate Normals
- The soil order, drainage, surface pH, and the 3 most extensive named soil series mapped in Milwaukee CountyUSDA NRCS SSURGO
- 5,747 documented contamination sites inside the county boundary, distance-sorted from its center — the closest Underground Storage Tanks record about 0.1 miles outFederal environmental registers
- Milwaukee County's boundary and the 154,533 acres inside itUS Census TIGER/Line 2025
- Which of 1,086 plants clear zones 6a and a ~217-day seasonGrowable Ground crop-matching engine
- Milwaukee County sitting wholly inside the Southeastern Wisconsin Till PlainsUS EPA Level III Ecoregions
- Open occurrence records documented in Milwaukee County for 2 tracked speciesGBIF derived datasets (CC0 / CC BY 4.0)
- Which agricultural compounds go onto Milwaukee County farmland, and roughly how muchUSGS NAWQA EPest county estimates
Inherited from a wider read
- The growing challenges every Wisconsin grower plans around — written at state scale, so they stay on the state guidefrom Wisconsin
What this page can’t tell you
- How the season shifts across Milwaukee County — the ~217 days above is one reading at its centre; the 12 towns below each carry their owntowns in this county →
- The soil pH, drainage, sun hours, and frost pockets on any one lot among Milwaukee County's 154,533 acreswhy one lot differs from the next →
- Which of those 5,747 documented sites actually reaches your soil — that needs your address, the wind, and the groundwater directionhow we read the record →
- Where cold air settles, which slopes face the sun, and which way the wind runs on your own ground — none of it survives being averaged over Milwaukee Countyread your own land →