Griggs County, in North Dakota, sits in USDA hardiness zone 4a — a range where zone-matched perennials and frost-aware annual timing set what succeeds.
Among the crops suited to this profile: cabbage, cranberry, turkish rocket, and collard greens. The site-level story — soil, sun, drainage — decides the rest.
Grounded in USDA PHZM 2023 · Growable Ground suitability scoring · NOAA 1991–2020 Climate Normals
Griggs County holds more than one microclimate.
Soils and elevations shift across Griggs 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 Griggs County — soil, climate, flood, and parcel records. How we handle your address.
No card required · your full report in seconds
Griggs County — the short answer
Griggs County, North Dakota: USDA zone 4a, about 162 days between hard freezes, across 454K acres.
- USDA zone
- 4a
- USDA PHZM 2023
- Last hard freeze (28°F)
- Apr 30
- NOAA 1991–2020 Climate Normals, 28°F
- First hard freeze (28°F)
- Oct 9
- NOAA 1991–2020 Climate Normals, 28°F
- Days between freezes
- ~162
- NOAA 1991–2020 Climate Normals, 28°F
- County area
- 454K 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 4a is Griggs County's average, not your lot's — a low corner or a tree line moves it. Against Griggs County's 162-day season, see what your own ground reads.
Heat in Griggs County
Across a year, Griggs County accumulates about 1,872 growing degree days above 50°F, about 41 fewer than the middle North Dakota county — ahead of 18 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 Griggs County
Across Griggs County, the ground is predominantly Mollisols, where Hamerly, Heimdal, and Barnes are the most extensive named soil series. The soil is generally well drained with a loam surface. Topsoil pH runs about 7.0–7.5, neutral. Rainfall drains through hydrologic group B soils.
Soil order
Mollisols
Drainage
Well drained
Prime farmland
43%
Hydric soils
15%
Soil still varies lot by lot — soil types explained.
How the ground varies across Griggs County
The USDA soil survey maps 31% of Griggs County as well drained — but another 68% drains differently: 28% somewhat poorly drained, 19% moderately well drained.
Hamerly is the most extensive named soil at 12% of mapped acres, then Heimdal (8%) and Barnes (7%).
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 Griggs County
Each reading below is measured for Griggs 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 Griggs County are well drained, in hydrologic group B — 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 Griggs County runs about pH 7.0–7.5, 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
Wet ground
MeasuredAbout 15% of Griggs County is mapped as hydric — wetland — soil.
If your lot falls in one of those pockets, a standard in-ground bed will fight waterlogging all season, and roots that need air will struggle.
Check how your own ground drains before you dig; raised beds or moisture-loving plantings turn a wet corner from a problem into a niche.
USDA NRCS SSURGO
Season length
MeasuredGriggs County runs about 162 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
The kind of country Griggs County is in
Griggs County sits in the Northern Glaciated Plains — EPA Level III, inside the wider Great Plains. One consistent ecological setting across the whole county.
What Grows in Griggs County
We scored all 1,086 plants against Griggs County's own USDA zone 4a and its own 162-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 Griggs County?
Almost never — the real question is what to plant next. Cool-season crops can go in from around Apr 2; tender transplants wait until two to three weeks after the last 28°F hard freeze, which lands near Apr 30 (NOAA 1991–2020 climate normals); and from midsummer, planting counts back from the first fall freeze around Oct 9 — long-season crops need about 90 days of runway, quick greens only 30. The tail of the season still works: sixty-day crops into late summer, quick greens after, garlic last of all.
What gets applied to farmland in Griggs County
USGS estimates 136,253 lb of Glyphosate on Griggs County farmland in 2019, its largest by weight, ahead of Metolachlor & Metolachlor-s (61,328 lb) and Metolachlor-s (46,513 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 Griggs County — and how to grow with it.
We checked the federal record across Griggs County — 317 documented sites across 3 of the 9 source types we track.
The most significant on record: 1 brownfield site. Former commercial or industrial land where legacy contamination may persist.
There's a meaningful federal record across Griggs 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 Griggs County
Closest first, across Griggs County. Listing isn't leaking, and distance isn't exposure.
- 146-060-14AAANitrate · 1.9 mi
- Grand Forks Air Force BaseUnderground Storage Tanks · 2.1 mi
- 146-060-01BCCNitrate · 2.6 mi
- 146-059-22BCCNitrate · 2.6 mi
- 146-060-22DDDNitrate · 2.7 mi
- 146-060-10DDDNitrate · 2.8 mi
- 146-059-04DCCNitrate · 2.9 mi
- 146-060-36CCCNitrate · 3.3 mi
- 146-060-16AAANitrate · 3.7 mi
- 146-060-34BBBNitrate · 4.0 mi
- 145-059-04CDDNitrate · 4.3 mi
- Farmers Oil CompanyUnderground Storage Tanks · 4.9 mi
6 more sites are on the record inside the same radius. See them on the map
Measured from Griggs 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 Griggs County.
Severity Distribution
across Griggs County
Highest-Severity Sites
A note from Gnorman
What an experienced grower watches for around here
In and around Griggs County, Nitrate runs higher than the national average — 282 sites across Griggs County. That's not a problem with your land — it's information about 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 Griggs 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 Griggs County average
Your land is one point inside Griggs County
Everything above resolves to Griggs County as a whole — one PHZM band and one county frost record, read across 454K 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 Griggs County Average
Griggs County Average
- ●USDA Zones 4a, averaged across Griggs County
- ●One soil character for all of Griggs County
- ●Frost dates read at Griggs County's scale: Apr 30 to Oct 9
YOUR Parcel
- ✓Your exact zone, not Griggs County's 4a
- ✓Your SSURGO soil type & pH
- ✓Your sun exposure, cast in 3D
See MY Growing Report
Read your parcel in Griggs County
Pull a site-specific report for your exact address in Griggs County, North Dakota — soil, sun, drainage, frost risk, and scored plant recommendations.
Three things about your lot that Griggs County averages can't show:
We read public map data around Griggs County — soil, climate, flood, and parcel records. How we handle your address.
25+ data sources read at your address, not the Griggs County average
How we know this about Griggs 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 Griggs County carries no record of its own, the figure is inherited and labelled — the resolution ledger below names each.
Common questions about Griggs County
When does frost risk typically end in Griggs County?
The last hard freeze (28°F) in Griggs County typically lands around Apr 30, 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 21.
How long is the growing season in Griggs County?
Measured between 28°F hard freezes, Griggs County sees about 162 frost-free days — roughly Apr 30 through Oct 9, per NOAA 1991–2020 climate normals. Tender crops work a shorter one: nearer May 21 to Sep 25, about 127 days.
Is the soil safe to grow vegetables in Griggs County?
The federal record around Griggs County is a meaningful one — 317 documented sites, mostly Nitrate entries (282), the nearest Nitrate record about 1.9 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.
Everything above is measured at Griggs County's scale — its 4a band and its 162-day season. Your yard writes its own version of Griggs 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 Griggs County’s own scale
8 of the readings below were taken at Griggs County's own scale — its own ~162-day span between 28°F freezes, the 3 most extensive soil series mapped here and 317 documented sites inside its boundary; one is borrowed from a wider read, named and linked below.
Measured here
- Griggs County's own USDA hardiness band, zones 4aUSDA PHZM 2023
- Griggs County's own 28°F hard-freeze dates and its ~162-day span between themNOAA 1991–2020 Climate Normals
- The soil order, drainage, surface pH, and the 3 most extensive named soil series mapped in Griggs CountyUSDA NRCS SSURGO
- 317 documented contamination sites inside the county boundary, distance-sorted from its center — the closest Nitrate record about 1.9 miles outFederal environmental registers
- Griggs County's boundary and the 453,558 acres inside itUS Census TIGER/Line 2025
- Which of 1,086 plants clear zones 4a and a ~162-day seasonGrowable Ground crop-matching engine
- Griggs County sitting wholly inside the Northern Glaciated PlainsUS EPA Level III Ecoregions
- Which agricultural compounds go onto Griggs 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 Griggs County — the ~162 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 Griggs County's 453,558 acreswhy one lot differs from the next →
- Which of those 317 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 Griggs Countyread your own land →