Adams County, in North Dakota, sits in USDA hardiness zone 4b — room for a real mix of vegetables, fruit, and perennials matched to the local frost calendar.
Reliable performers under these conditions include cabbage, cranberry, cilantro, and collard greens; what your own ground favors still comes down to its soil, sun, and drainage.
Grounded in USDA PHZM 2023 · Growable Ground suitability scoring · NOAA 1991–2020 Climate Normals
Adams County holds more than one microclimate.
Soils and elevations shift across Adams 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 Adams County — soil, climate, flood, and parcel records. How we handle your address.
No card required · your full report in seconds
Adams County — the short answer
Adams County, North Dakota: USDA zone 4b, about 149 days between hard freezes, across 632K acres.
- USDA zone
- 4b
- USDA PHZM 2023
- Last hard freeze (28°F)
- May 7
- NOAA 1991–2020 Climate Normals, 28°F
- First hard freeze (28°F)
- Oct 3
- NOAA 1991–2020 Climate Normals, 28°F
- Days between freezes
- ~149
- NOAA 1991–2020 Climate Normals, 28°F
- County area
- 632K 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 4b is Adams County's average, not your lot's — a low corner or a tree line moves it. Against Adams County's 149-day season, see what your own ground reads.
Heat in Adams County
Across a year, Adams County accumulates about 1,931 growing degree days above 50°F, about 18 more than the middle North Dakota county — ahead of 32 of North Dakota’s 53 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 Adams County
Across Adams County, the ground is predominantly Mollisols, where Vebar, Belfield, and Daglum are the most extensive named soil series. The soil is generally well drained with a loam surface. Topsoil pH runs about 6.5–7.2, neutral. Rainfall drains through hydrologic group C soils.
Soil order
Mollisols
Drainage
Well drained
Prime farmland
5%
Hydric soils
5%
Soil still varies lot by lot — soil types explained.
How the ground varies across Adams County
The USDA soil survey maps 58% of Adams County as well drained — but another 42% drains differently: 21% moderately well drained, 14% somewhat excessively drained.
Vebar is the most extensive named soil at 9% of mapped acres, then Belfield (9%) and Daglum (9%).
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 Adams County
Each reading below is measured for Adams 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 Adams County are well drained, in hydrologic group C — ground that drains quickly.
The upside is soil you can work early in spring and roots that never drown; the cost is that fast-draining ground dries out fast and leaches nutrients away before plants can use them.
Work in compost and mulch to hold moisture and feed, and water more often in short doses than deep and rarely.
USDA NRCS SSURGO
Surface pH
MeasuredTopsoil across Adams County runs about pH 6.5–7.2, 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
MeasuredAdams County runs about 149 days between hard freezes — a short growing season.
Long-maturing crops like melons, sweet potatoes, and winter squash can run out of runway before the first hard freeze, ripening late or not at all.
Lead with fast-maturing varieties, and stretch the season on both ends with cold frames, low tunnels, or a greenhouse.
NOAA 1991–2020 Climate Normals
Winter hardiness
MeasuredAdams County 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 Adams County is in
Adams County sits in the Northwestern Great Plains — EPA Level III, inside the wider Great Plains. One consistent ecological setting across the whole county.
What Grows in Adams County
We scored all 1,086 plants against Adams County's own USDA zone 4b and its own 149-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 North Dakota profile.
Is it too late to plant in Adams County?
Usually not — gardeners here simply switch what goes in the ground as the season moves. Cool-season crops can go in from around Apr 9; tender transplants wait until two to three weeks after the last 28°F hard freeze, which lands near May 7 (NOAA 1991–2020 climate normals); and from midsummer, planting counts back from the first fall freeze around Oct 3 — long-season crops need about 90 days of runway, quick greens only 30. In a season this compact, fast finishers and cold-hardy greens do the late work, and garlic tucked in before the freeze repays you next summer.
What gets applied to farmland in Adams County
USGS estimates 225,624 lb of Glyphosate on Adams County farmland in 2019, its largest by weight, ahead of Dicamba (29,278 lb) and Dimethenamid-p (28,501 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 Adams County — and how to grow with it.
We checked the federal record across Adams County — 249 documented sites across 4 of the 9 source types we track.
The most significant on record: 1 Toxics Release Inventory facility. Active industrial facilities reporting chemical releases to air, water, and land.
There's a meaningful federal record across Adams 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 Adams County
Closest first, across Adams County. Listing isn't leaking, and distance isn't exposure.
- 130-094-07DDD2Nitrate · 2.7 mi
- 130-094-07DDD1Nitrate · 2.7 mi
- 130-095-28AAANitrate · 2.9 mi
- 131-095-27CCBNitrate · 3.0 mi
- 130-094-31BCCNitrate · 4.3 mi
- 131-095-22BAANitrate · 4.5 mi
- 131-095-15DCCNitrate · 4.6 mi
- 131-094-20CBC3Nitrate · 4.7 mi
- 131-094-20CBC1Nitrate · 4.7 mi
- 131-094-20CBC2Nitrate · 4.7 mi
- 129-095-02DADNitrate · 5.2 mi
- 130-096-14AABNitrate · 5.5 mi
6 more sites are on the record inside the same radius. See them on the map
Measured from Adams 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 Adams County.
Total Sites
249
across Adams County
Risk Level
Elevated
Highest-severity
1 Toxics Release Inventory facility
Sources Checked
across Adams County
Severity Distribution
across Adams County
Highest-Severity Sites
A note from Gnorman
What an experienced grower watches for around here
In and around Adams County, Nitrate runs higher than the national average — 230 sites across Adams County. 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 Adams 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 Adams County average
Your land is one point inside Adams County
Everything above resolves to Adams County as a whole — one PHZM band and one county frost record, read across 632K 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 Adams County Average
Adams County Average
- ●USDA Zones 4b, averaged across Adams County
- ●One soil character for all of Adams County
- ●Frost dates read at Adams County's scale: May 7 to Oct 3
YOUR Parcel
- ✓Your exact zone, not Adams County's 4b
- ✓Your SSURGO soil type & pH
- ✓Your sun exposure, cast in 3D
See MY Growing Report
Read your parcel in Adams County
Pull a site-specific report for your exact address in Adams County, North Dakota — soil, sun, drainage, frost risk, and scored plant recommendations.
Three things about your lot that Adams County averages can't show:
We read public map data around Adams County — soil, climate, flood, and parcel records. How we handle your address.
25+ data sources read at your address, not the Adams County average
How we know this about Adams 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 Adams County carries no record of its own, the figure is inherited and labelled — the resolution ledger below names each.
Common questions about Adams County
When does frost risk typically end in Adams County?
The last hard freeze (28°F) in Adams County typically lands around May 7, 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 28.
How long is the growing season in Adams County?
Measured between 28°F hard freezes, Adams County sees about 149 frost-free days — roughly May 7 through Oct 3, per NOAA 1991–2020 climate normals. Tender crops work a shorter one: nearer May 28 to Sep 19, about 114 days.
Is the soil safe to grow vegetables in Adams County?
The federal record around Adams County is a meaningful one — 249 documented sites, mostly Nitrate entries (230), the nearest Nitrate record about 2.7 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 gardeners stretch the season in Adams County?
With about 149 frost-free days between hard freezes, Adams County rewards the classic extension moves: floating row cover buys roughly two to four extra weeks at each shoulder — on this season that is a working window nearer 177 to 205 days — and cold frames or low tunnels buy more. Starting transplants indoors ahead of the May 7 hard-freeze normal stretches the season without touching the calendar.
Everything above is measured at Adams County's scale — its 4b band and its 149-day season. Your yard writes its own version of Adams 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 North Dakota's frost window, season length, and soil profile against the plant's real requirements.
What this page reads at Adams County’s own scale
8 of the readings below were taken at Adams County's own scale — its own ~149-day span between 28°F freezes, the 3 most extensive soil series mapped here and 249 documented sites inside its boundary; one is borrowed from a wider read, named and linked below.
Measured here
- Adams County's own USDA hardiness band, zones 4bUSDA PHZM 2023
- Adams County's own 28°F hard-freeze dates and its ~149-day span between themNOAA 1991–2020 Climate Normals
- The soil order, drainage, surface pH, and the 3 most extensive named soil series mapped in Adams CountyUSDA NRCS SSURGO
- 249 documented contamination sites inside the county boundary, distance-sorted from its center — the closest Nitrate record about 2.7 miles outFederal environmental registers
- Adams County's boundary and the 632,029 acres inside itUS Census TIGER/Line 2025
- Which of 1,086 plants clear zones 4b and a ~149-day seasonGrowable Ground crop-matching engine
- Adams County sitting wholly inside the Northwestern Great PlainsUS EPA Level III Ecoregions
- Which agricultural compounds go onto Adams County farmland, and roughly how muchUSGS NAWQA EPest county estimates
Inherited from a wider read
- The growing challenges every North Dakota grower plans around — written at state scale, so they stay on the state guidefrom North Dakota
What this page can’t tell you
- How the season shifts across Adams County — the ~149 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 Adams County's 632,029 acreswhy one lot differs from the next →
- Which of those 249 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 Adams Countyread your own land →