Lennox, South Dakota, sits in USDA hardiness zones 5a-6b — a zone band wide enough that plant choice, not possibility, is the interesting question.
Reliable performers under these conditions include tomato, grape (marquette), black hills spruce, and potato; what your own ground favors still comes down to its soil, sun, and drainage.
Even in Lennox, 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 Lennox 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 7
Town normal — light frosts run a few weeks later
First Hard Freeze (28°F)
Oct 30
Town normal — light frosts arrive a few weeks earlier
City Area
1K acres
Hardiness Zone Range
Zone maps are averages across Lennox. 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.
What Grows in Lennox
Plants matched to Lennox's USDA zones 5a-6b — each links to its full growing profile.





Is it too late to plant in Lennox?
For most of the year, no — what changes is which crops still fit the days remaining. Cool-season crops can go in from around Mar 10; tender transplants wait until two to three weeks after the last 28°F hard freeze, which lands near Apr 7 (NOAA 1991–2020 climate normals); and from midsummer, planting counts back from the first fall freeze around Oct 30 — 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 South Dakota
What an experienced grower plans around here — each one has a move.

Extreme cold and short growing season
Cold-proven varieties and a high tunnel turn a short prairie season into a reliable one — the northern-plains standard.

Low rainfall in western SD
West-river gardens run on drip and mulch — putting the water plan first makes the dry summers routine.

Wind exposure on the open prairie
A windbreak is the best structure you can plant on the prairie — even a shrub row shifts the microclimate.
For cultivar selection, pest pressure, and planting-time guidance specific to South Dakota, the SDSU 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
268
within ~10 miles of Lennox
Risk Level
Elevated
Highest-severity
10 Toxics Release Inventory facilities
Sources Checked
within ~10 miles of Lennox
Severity Distribution
within ~10 miles of Lennox
Highest-Severity Sites

A note from Gnorman
What an experienced grower watches for around here
In and around Lennox, Nitrate runs higher than the national average — 200 sites nearby. It's not cause for alarm — it's worth knowing, and there's a sensible way to grow around it.
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 Lennox
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:
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
Lennox 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
Read your specific parcel in Lennox
Pull a site-specific report for your exact address in Lennox, South Dakota — soil, sun, drainage, frost risk, and scored plant recommendations.
Three things about your exact spot that zone averages miss:
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 Lennox, South Dakota
- USDA Hardiness Zones: 5a-6b (USDA PHZM 2023)
- Last Hard Freeze (28°F): Apr 7 (town normal, NOAA 1991–2020 Climate Normals — light frosts can follow for a few weeks)
- First Hard Freeze (28°F): Oct 30 (town normal, NOAA 1991–2020 Climate Normals — light frosts can arrive a few weeks earlier)
- Days Between Hard Freezes: ~206 (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 Lennox, South Dakota?
Lennox 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 Lennox?
For most of the year, no — what changes is which crops still fit the days remaining. Cool-season crops can go in from around Mar 10; tender transplants wait until two to three weeks after the last 28°F hard freeze, which lands near Apr 7 (NOAA 1991–2020 climate normals); and from midsummer, planting counts back from the first fall freeze around Oct 30 — 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 Lennox?
The last hard freeze (28°F) in Lennox typically lands around Apr 7, 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 Lennox?
The first hard freeze (28°F) in Lennox typically arrives around Oct 30, 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 Lennox?
Lennox's zones 5a-6b support a wide range — strong performers include Tomato, Grape (Marquette), Black Hills Spruce, Potato, and Rhubarb. 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 Lennox, really?
Officially, Lennox 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 Lennox?
The federal record around Lennox is a meaningful one — 268 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 Lennox?
As the season closes around the first 28°F hard freeze near Oct 30 (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 Lennox 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.
