What Grows in Denmark, Wisconsin

USDA Zones 4a-5b · 1K acres

Denmark, Wisconsin, sits in USDA hardiness zones 4a-5b — a range where zone-matched perennials and frost-aware annual timing set what succeeds.

Reliable performers under these conditions include cranberry, cherry, potato, and ginseng; what your own ground favors still comes down to its soil, sun, and drainage.

Score your parcel · free

Even in Denmark, 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 Denmark lot. Enter your address and we'll score 1,112 plants against your land's actual soil, sun, and frost.

We read public map data for this spot — soil, climate, flood, and parcel records. How we handle your address.

No card required · your full report in seconds

Quick Facts

USDA Zones

4a-5b

Last Hard Freeze (28°F)

Apr 13

Town normal — light frosts run a few weeks later

First Hard Freeze (28°F)

Nov 6

Town normal — light frosts arrive a few weeks earlier

Town Area

1K acres

Hardiness Zone Range

4a
5b
3a (Cold)13b (Hot)

Zone maps are averages across Denmark. Your yard's slope, trees, and frost pockets shift what actually grows — see your land's exact reading.

Soil varies lot by lot — soil types explained.

Is it too late to plant in Denmark?

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 16; tender transplants wait until two to three weeks after the last 28°F hard freeze, which lands near Apr 13 (NOAA 1991–2020 climate normals); and from midsummer, planting counts back from the first fall freeze around Nov 6 — 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.

Growing Challenges in Wisconsin

What an experienced grower plans around here — each one has a move.

Cold winters (-30F in northern WI)

Plant perennials rated for the cold you actually get — northern Wisconsin rewards zone honesty with decades of returns.

Short growing season (110-140 frost-free days)

Indoor starts plus a cold frame stretch the season on both ends — standard practice from Madison to Superior.

Sandy central soils drain too quickly

The Central Sands fix is organic matter — compost and cover crops, every year, until the ground holds its own water.

For cultivar selection, pest pressure, and planting-time guidance specific to Wisconsin, the UW–Madison Division of Extension is the authoritative local source.

Environmental Intelligence

Understanding what's nearby helps you make informed decisions about where and how to grow.

Total Sites

261

within ~10 miles of Denmark

Risk Level

Elevated

Highest-severity

2 Superfund sites

Severity Distribution

within ~10 miles of Denmark

High2Moderate77Low182

Highest-Severity Sites

R L O'Keefe & Sons INC. Landfill
Superfund · Superfund (Non-NPL)
Schneske Property (Former)
Superfund · Superfund (Non-NPL)
Baycare Aurora LLC D/Ba Aurora Baycare Medical Ctr
Underground Storage Tanks · Open UST(S)
Belgioioso Cheese
Toxics Release Inventory · 5420wblgsc5911c
Belgioioso Cheese INC Denmark
Toxics Release Inventory · 54208blgsc581ct

A note from Gnorman

What an experienced grower watches for around here

In and around Denmark, two things run higher than the national average — CAFO (13 sites) and Toxic Release Inventory (21 sites). 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.

Toxic Release Inventory: TRI facilities report annual chemical releases to air, water, and land.

Wash all produce consumed raw thoroughly, especially leafy greens grown near CAFOs.

Check prevailing wind direction — downwind parcels face higher exposure than upwind or crosswind locations.

Free Report

Check your specific parcel in Denmark

Get exact proximity distances to contamination sources for your specific parcel — plus soil, sun, drainage, and 1,112 plant recommendations.

Three things about your exact spot that zone averages miss:

Your soil pHYour frost-free daysYour sun & shade

We read public map data for this spot — soil, climate, flood, and parcel records. How we handle your address.

25+ data sources analyzed in seconds

Your Specific Parcel Matters

Denmark Average

  • USDA Zones 4a-5b
  • Generic soil type for the area
  • State-average frost dates

YOUR Parcel

  • Your exact hardiness zone
  • Your SSURGO soil type & pH
  • Your sun exposure, cast in 3D

See MY Growing Report

Free Report

Read your specific parcel in Denmark

Pull a site-specific report for your exact address in Denmark, Wisconsin — soil, sun, drainage, frost risk, and scored plant recommendations.

Three things about your exact spot that zone averages miss:

Your soil pHYour frost-free daysYour sun & shade

We read public map data for this spot — soil, climate, flood, and parcel records. How we handle your address.

25+ data sources analyzed in seconds

Key Growing Facts for Denmark, Wisconsin

  • USDA Hardiness Zones: 4a-5b (USDA PHZM 2023)
  • Last Hard Freeze (28°F): Apr 13 (town normal, NOAA 1991–2020 Climate Normals — light frosts can follow for a few weeks)
  • First Hard Freeze (28°F): Nov 6 (town normal, NOAA 1991–2020 Climate Normals — light frosts can arrive a few weeks earlier)
  • Days Between Hard Freezes: ~207 (town normal, NOAA 1991–2020 Climate Normals)
  • Land Area: 1K acres (US Census TIGER 2025)

Zone data: USDA ARS Plant Hardiness Zone Map 2023. Climate data: NOAA NCEI. Boundaries: US Census TIGER/Line 2025.

Frequently Asked Questions

What hardiness zone is Denmark, Wisconsin?

Denmark sits in USDA hardiness zones 4a-5b, per the USDA Plant Hardiness Zone Map 2023. Zones reflect average annual extreme minimum temperatures from 1991–2020 weather data.

Is it too late to plant in Denmark?

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 16; tender transplants wait until two to three weeks after the last 28°F hard freeze, which lands near Apr 13 (NOAA 1991–2020 climate normals); and from midsummer, planting counts back from the first fall freeze around Nov 6 — 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.

When does frost risk typically end in Denmark?

The last hard freeze (28°F) in Denmark typically lands around Apr 13, per NOAA 1991–2020 climate normals — an earlier marker than the light-frost dates many planting charts quote. That marks the hard freeze, not the last light frost — light frosts can still bite for a few more weeks, so tender transplants usually wait another 2–3 weeks.

When is the first frost in Denmark?

The first hard freeze (28°F) in Denmark typically arrives around Nov 6, per NOAA 1991–2020 climate normals — the point most tender summer crops finish. Lighter frosts usually reach a couple of weeks earlier, so watch the forecast from late summer on and harvest or cover tender plants before the first cold night.

What vegetables grow in Denmark?

Denmark's zones 4a-5b support a wide range — strong performers include Cranberry, Cherry, Potato, Ginseng, and Sugar Maple. What actually takes on any one site comes down to its soil, sun, and drainage, and we score each plant against the real conditions at your address.

Which hardiness zone is Denmark, really?

Officially, Denmark sits in USDA zones 4a-5b (USDA PHZM 2023) — but a zone is a 30-year average of winter's coldest night across an area, and it can't see any one yard. A south-facing slope, a tree line, or a low frost pocket can shift a single site by half a zone either way, which is why neighboring gardeners often quote different numbers. We read the conditions at your exact address — soil, sun, slope, and frost — and score 1,112 plants against what's actually there.

Is the soil safe to grow vegetables in Denmark?

The federal record around Denmark is a meaningful one — 261 documented sites — 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 Denmark?

As the season closes around the first 28°F hard freeze near Nov 6 (NOAA 1991–2020 climate normals), a few moves buy time: cover tender plants with floating row cover or an old sheet on still, clear nights, water the soil the afternoon before a freeze so it holds warmth overnight, and harvest frost-tender crops like tomatoes, peppers, and basil before the first hard night. Hardy greens and root crops shrug off light frost and often sweeten after it, so leave them in.

Everything on this page is a Denmark average. Your yard writes its own version — we read soil, sun, drainage, and frost at your exact address. Try it for 14 days — no card required.