What Grows in Round Lake, Minnesota

USDA Zones 5a-6b · 464 acres

Round Lake, Minnesota, sits in USDA hardiness zones 5a-6b — a zone band wide enough that plant choice, not possibility, is the interesting question.

Growers here do well with honeycrisp apple, wild rice, tomato, and grape (marquette) — with the usual caveat that any single yard's soil, sun, and drainage cast the deciding vote.

Score your parcel · free

Even in Round Lake, 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 Round Lake 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.

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Quick Facts

USDA Zones

5a-6b

Last Hard Freeze (28°F)

Apr 11

Town normal — light frosts run a few weeks later

First Hard Freeze (28°F)

Oct 29

Town normal — light frosts arrive a few weeks earlier

City Area

464 acres

Hardiness Zone Range

5a
6b
3a (Cold)13b (Hot)

Zone maps are averages across Round Lake. 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 Round Lake?

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 14; tender transplants wait until two to three weeks after the last 28°F hard freeze, which lands near Apr 11 (NOAA 1991–2020 climate normals); and from midsummer, planting counts back from the first fall freeze around Oct 29 — long-season crops need about 90 days of runway, quick greens only 30. A long window like this one runs successions deep into fall — and even its last weeks take quick greens and garlic.

Growing Challenges in Minnesota

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

Extreme cold (zone 3a: -40F) limits many species

Plant to zone 3 realities and the garden thrives — the hardy-plant palette here is deeper than most catalogs suggest.

Short growing season (100-140 frost-free days)

Start transplants indoors and add a cold frame — the standard Minnesota moves that stretch a short season into a full one.

Heavy clay soils in the Red River Valley

Valley clay grows world-class crops once drainage is handled — raised beds do it instantly, compost does it permanently.

For cultivar selection, pest pressure, and planting-time guidance specific to Minnesota, the University of Minnesota 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

212

within ~10 miles of Round Lake

Risk Level

Elevated

Highest-severity

8 Toxics Release Inventory facilities

Severity Distribution

within ~10 miles of Round Lake

High1Moderate79Low132

Highest-Severity Sites

Worthington
PFAS Sampling · PFAS Detected
100520
Nitrate Monitoring · Well
100520
Nitrate Monitoring · Well
101n39w24bbd 03 Round Lake
Nitrate Monitoring · Well
101n39w24bbd 03 Round Lake
Nitrate Monitoring · Well

A note from Gnorman

What an experienced grower watches for around here

In and around Round Lake, two things run higher than the national average — CAFO (7 sites) and Nitrate (56 sites). It's not cause for alarm — it's worth knowing, and there's a sensible way to grow around it.

CAFO: CAFOs pose a different contamination profile than chemical sources.

Nitrate: Nitrate contamination primarily comes from agricultural fertilizer runoff and failing septic systems.

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

Test well water for nitrate if you rely on a private well for irrigation (EPA standard: 10 mg/L).

Free Report

Check your specific parcel in Round Lake

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

Round Lake Average

  • USDA Zones 5a-6b
  • 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 Round Lake

Pull a site-specific report for your exact address in Round Lake, Minnesota — 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 Round Lake, Minnesota

  • USDA Hardiness Zones: 5a-6b (USDA PHZM 2023)
  • Last Hard Freeze (28°F): Apr 11 (town normal, NOAA 1991–2020 Climate Normals — light frosts can follow for a few weeks)
  • First Hard Freeze (28°F): Oct 29 (town normal, NOAA 1991–2020 Climate Normals — light frosts can arrive a few weeks earlier)
  • Days Between Hard Freezes: ~201 (town normal, NOAA 1991–2020 Climate Normals)
  • Land Area: 464 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 Round Lake, Minnesota?

Round Lake sits in USDA hardiness zones 5a-6b, 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 Round Lake?

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 14; tender transplants wait until two to three weeks after the last 28°F hard freeze, which lands near Apr 11 (NOAA 1991–2020 climate normals); and from midsummer, planting counts back from the first fall freeze around Oct 29 — long-season crops need about 90 days of runway, quick greens only 30. A long window like this one runs successions deep into fall — and even its last weeks take quick greens and garlic.

When does frost risk typically end in Round Lake?

The last hard freeze (28°F) in Round Lake typically lands around Apr 11, 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 Round Lake?

The first hard freeze (28°F) in Round Lake typically arrives around Oct 29, 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 Round Lake?

Round Lake's zones 5a-6b support a wide range — strong performers include Honeycrisp Apple, Wild Rice, Tomato, Grape (Marquette), and Red Pine. 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 Round Lake, really?

Officially, Round Lake sits in USDA zones 5a-6b (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 Round Lake?

The federal record around Round Lake is a meaningful one — 212 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 Round Lake?

As the season closes around the first 28°F hard freeze near Oct 29 (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 Round Lake 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.