Emerald, Wisconsin, sits in USDA hardiness zone 4b — a range where zone-matched perennials and frost-aware annual timing set what succeeds.
A short list that earns its place here — cabbage, cranberry, turkish rocket, and collard greens — with any one site's soil, sun, and drainage making the final cut.
Even in Emerald, 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 Emerald 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 Emerald — soil, climate, flood, and parcel records. How we handle your address.
No card required · your full report in seconds
Emerald — the short answer
Emerald, Wisconsin: USDA zone 4b, about 167 days between hard freezes, across 1K acres of town.
- USDA zone
- 4b
- USDA PHZM 2023
- Last hard freeze (28°F)
- Apr 27
- NOAA 1991–2020 Climate Normals, 28°F — this town
- First hard freeze (28°F)
- Oct 11
- NOAA 1991–2020 Climate Normals, 28°F — this town
- Days between freezes
- ~167
- NOAA 1991–2020 Climate Normals, 28°F — this town
- Town area
- 1K 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 Emerald's average, not your lot's — a low corner or a tree line moves it. Against Emerald's 167-day season, see what your own ground reads.
Soil varies lot by lot — soil types explained.
What this means for growing in Emerald
Each reading below is measured for Emerald itself — here is what it means for a garden here, and the move an experienced grower makes about it.
Season length
MeasuredEmerald runs about 167 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
MeasuredEmerald 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 Emerald is in
Emerald sits in the North Central Hardwood Forests — EPA Level III, inside the wider Eastern Temperate Forests. That is read at Emerald's own centroid, and it is not what its county reads: St. Croix County is mostly Western Corn Belt Plains. The wider page above you is answering a different question about different ground.
What Grows in Emerald
Every plant below cleared Emerald's own zone 4b and its 167-day season. Each card opens that plant's Wisconsin profile. How we score.
Is it too late to plant in Emerald?
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 30; tender transplants wait until two to three weeks after the last 28°F hard freeze, which lands near Apr 27 (NOAA 1991–2020 climate normals); and from midsummer, planting counts back from the first fall freeze around Oct 11 — 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 Emerald
Closest first, within ~10 miles of Emerald. Listing isn't leaking, and distance isn't exposure.
- FOREST CROSSROADS INCUnderground Storage Tanks · 2400 ft
- N R FARMERS UNION CO OPUnderground Storage Tanks · 2400 ft
- EMERALD TIRE & AUTO SERVICEUnderground Storage Tanks · 2500 ft
- JERRYS SERVICEUnderground Storage Tanks · 2600 ft
- WEYER FARMSBrownfields · 2.6 mi
- BILLS REPAIR SERVICEBrownfields · 2.6 mi
- NORMAN LOGTERMANUnderground Storage Tanks · 3.4 mi
- NEW RICHMOND FARMERS UNION COOP OILUnderground Storage Tanks · 3.5 mi
- SC-31/15W/30-0673Nitrate · 3.5 mi
- BRIAN A HURTGENUnderground Storage Tanks · 3.6 mi
- CLIFFS REPAIRBrownfields · 3.9 mi
- DALE BERENDSToxics Release Inventory · 4.0 mi
6 more sites are on the record inside the same radius. See them on the map
Measured from Emerald'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 Emerald.
Total Sites
213
within ~10 miles of Emerald
Risk Level
Elevated
Highest-severity
1 Superfund site (none NPL-listed)
Sources Checked
within ~10 miles of Emerald
Severity Distribution
within ~10 miles of Emerald
Highest-Severity Sites
A note from Gnorman
What an experienced grower watches for around here
In and around Emerald, Nitrate runs higher than the national average — 58 sites within ~10 miles of Emerald. Knowing it is half the work — and it's nothing a thoughtful grower can't plan for.
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 Emerald
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 Emerald average
Your land is one point inside Emerald
Everything above resolves to Emerald as a whole — one PHZM band and one 28°F frost record, read across 1K 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 Emerald Average
Emerald Average
- ●USDA Zones 4b, averaged across Emerald
- ●One soil character for all of Emerald
- ●Frost dates read at Emerald's scale: Apr 27 to Oct 11
YOUR Parcel
- ✓Your exact zone, not Emerald's 4b
- ✓Your SSURGO soil type & pH
- ✓Your sun exposure, cast in 3D
See MY Growing Report
Read your specific parcel in Emerald
Pull a site-specific report for your exact address in Emerald, Wisconsin — soil, sun, drainage, frost risk, and scored plant recommendations.
Three things about your lot that Emerald averages can't show:
We read public map data around Emerald — soil, climate, flood, and parcel records. How we handle your address.
25+ data sources read at your address, not the Emerald average
How we know this about Emerald
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 Emerald’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 Emerald
When does frost risk typically end in Emerald?
The last hard freeze (28°F) in Emerald typically lands around Apr 27, 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 18.
When is the first frost in Emerald?
The first hard freeze (28°F) in Emerald typically arrives around Oct 11, per NOAA 1991–2020 climate normals — the point tender summer crops finish. Lighter frosts run ahead of it, near Sep 27, so the watching starts about Sep 11 — about 167 days after the spring freeze cleared.
How long is the growing season in Emerald?
Measured between 28°F hard freezes, Emerald sees about 167 frost-free days — roughly Apr 27 through Oct 11, per NOAA 1991–2020 climate normals. Tender crops work a shorter one: nearer May 18 to Sep 27, about 132 days.
Is the soil safe to grow vegetables in Emerald?
The federal record around Emerald is a meaningful one — 213 documented sites, mostly Underground Storage Tanks entries (99), the nearest Underground Storage Tanks record about 0.5 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 Emerald?
From about Sep 11 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 11 (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 11. Hardy greens and roots shrug off light frost and sweeten after it — leave them in.
Everything above is measured at Emerald's scale — its 4b band and its 167-day season. Your yard writes its own version of Emerald'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 Emerald’s own scale
6 of the readings below were taken at Emerald's own scale — its own ~167-day season between 28°F freezes, the 1,194 acres it covers and 213 documented sites around it; 4 are borrowed from a wider read, named and linked below.
Measured here
- Emerald's own USDA hardiness band, zones 4bUSDA PHZM 2023
- Emerald's own 28°F hard-freeze dates, about Apr 27 and Oct 11 and the ~167-day span between themNOAA 1991–2020 Climate Normals
- 213 documented contamination sites on the federal record near Emerald, the closest Underground Storage Tanks record about 0.5 miles out from the town centreFederal environmental registers
- Emerald's boundary and the 1,194 acres inside itUS Census TIGER/Line 2025
- Which of 1,086 plants clear zones 4b and a ~167-day seasonGrowable Ground crop-matching engine
- Emerald sits in the North Central Hardwood Forests — not the ecoregion its county mostly readsUS EPA Level III Ecoregions
Inherited from a wider read
- Soil character — no town-scale survey exists, so Emerald's 1,194 acres read through its county's SSURGO summaryfrom St. Croix County
- Growing-degree days and winter chill — measured county-wide only, so the county page carries themfrom St. Croix 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 St. Croix County
What this page can’t tell you
- The soil pH, drainage, sun hours, and frost pockets on any one lot among Emerald's 1,194 acreswhy one lot differs from the next →
- Which side of Emerald you're on — a low spot frosts first and a south wall warms early, and one normal is being asked to speak for all 1,194 acresreading your own microclimate →
- How close that record sits to YOUR lot — the closest Underground Storage Tanks record about 0.5 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 Emerald-wide figureread your own land →
More in Wisconsin
Wider growing context
What grows across WisconsinEmerald sits outside our named growing regions, so Wisconsin as a whole is its closest context here.
Nearby growing guides