skirret (Sium sisarum), photographi

Can I Grow Skirret in North Dakota?

USDA Zones 3b-4b · Plant zone range 5-9

Unlikely — Zone Mismatch

skirret (zones 5-9) does not overlap with North Dakota's zone range (3b-4b). Growing outdoors is unlikely without significant protection.

Skirret in North Dakota — the short answer

Skirret in North Dakota: hardy in zones 5–9, part sun, against a state median of ~157 frost-free days.

Plant zones
5-9
Manual horticultural correction (source not retained); NC State Extension and Missouri Botanical Garden, with the remaining rows from other published sources or Growable Ground compilation
North Dakota zones
3b-4b
USDA PHZM 2023
Frost window
Apr 30 - May 6 – Oct 4 - Oct 9
NOAA RCC ACIS 1991-2020, 28°F
Shortest county season
141 days
NOAA Regional Climate Centers ACIS, 1991-2020, county 28°F killing freeze

Plant data: Growable Ground Plant Database, compiled from FAO ECOCROP, USDA PLANTS and university Extension sources — per-field provenance varies and is published with the dataset.

Score your parcel · free

Your yard isn't the whole zone.

North Dakota spans zones 3b-4b, but your yard has its own microclimate — slope, trees, and low spots shift frost and sun across a single parcel. Enter your address and we'll score skirret 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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North Dakota is not one climate

North Dakota’s winter-low ladder runs across 53 counties, from zone 3.5 in Bottineau County to zone 4.5 in Stutsman County. That is 10°F between the two counties’ average coldest night — the difference between skirret overwintering in the ground and coming under cover.

3.5 zonesBottineau County4.5 zonesStutsman County

The middle half of 53 counties runs 44 zones, with a median of 4 zones — a 1-zone span end to end.

Measured across 53 North Dakota counties. USDA PHZM 2023, per county. Quartiles are order statistics — every figure shown is a value a real county recorded, not an interpolation. Your own site sits somewhere inside this range; a parcel report resolves where.

Where Skirret Stands in North Dakota

Skirret is rated for zones 59 — a cold floor USDA puts at -20 to -10°F. No North Dakota county sits inside it, so in open ground this is a grown-under-cover plant here rather than a bed plant — which is a statement about North Dakota winters, not about skirret.

Below the zone 5 floor

53 counties

3 of 53 shown

Winter cold is the limit here — the same plant works in a container that comes under cover.

County hardiness zones: USDA Plant Hardiness Zone Map (PHZM) 2023, per county. A zone is a 10°F band of average annual extreme minimum temperature, so the floor above is the band the plant's rating denotes, not a single measured kill point. Slope, shelter and cold-air drainage routinely move a site half a zone either way from its county figure — which is the part only your address resolves.

Zone Comparison

Skirret Needs

  • USDA Zones: 5-9
  • Frost-Free Days: 40+
  • Sun: Part Sun

North Dakota Has

  • USDA Zones: 3b-4b
  • Last Hard Freeze (28°F): Apr 30 - May 6
  • First Hard Freeze (28°F): Oct 4 - Oct 9
  • Annual Rainfall: 14-22 inches
  • Common Soils: Prairie loam, Clay (Red River Valley), Sandy loam

Plant Zone Range (zones 5-9)

5a
9b
3a (Cold)13b (Hot)

Preferred Soil pH

3.5 (Acidic)7.0 (Neutral)9.0 (Alkaline)
Highlighted range: pH 5.57.5

Plant data: Growable Ground Plant Database, compiled from FAO ECOCROP, USDA PLANTS, and university Extension sources — per-field provenance varies and is published with the dataset. State data: USDA ARS PHZM 2023, NOAA Climate Normals, NRCS SSURGO.

When to Plant Skirret in North Dakota

The frost window

Across North Dakota, the last spring hard freeze (28°F) clears between Apr 30 and May 6, and the first fall hard freeze lands between Oct 4 and Oct 9 (NOAA Regional Climate Centers ACIS, 1991-2020). Counting from the latest last freeze to the earliest first freeze, that's a 151-day window you can count on — up to 162 days on a mild site in a kind year. That marks the hard freeze, not the last light frost, so tender transplants usually wait another 2-3 weeks.

When to start the seed

Those dates are when skirret goes out, not when it starts. It is sown under cover about 6 weeks ahead, so counting back from North Dakota's late-side last freeze of May 6 is what fixes your sowing date — and a yard that clears frost earlier than the state's late date starts earlier still.

Frost window: NOAA Climate Normals 1991-2020. Plant timing fields: Growable Ground Plant Database — frost-free days from FAO ECOCROP, days to harvest from university Extension production guides, and growing-degree-day and chill-hour minimums that are compilation estimates rather than published figures. Your site's own frost dates can run earlier or later than the state range — a parcel report pins them down.

Growing Season Fit

The zone check says skirret does not survive a North Dakota winter in the ground. The season figures below measure a different question — whether it could finish a season here at all — and they only bear on North Dakota under protection.

Frost-free days

Skirret wants 40+ frost-free days; a typical North Dakota site sees ~157 (NOAA Regional Climate Centers ACIS, 1991-2020). That leaves comfortable headroom for succession planting.

GDD and chill-hour figures are computed from PRISM 1991-2020 monthly climate normals; frost-free days from NOAA Regional Climate Centers ACIS, 1991-2020. Each is the state median across its counties (P25/P75 span the within-state spread). Hardiness-zone range is USDA PHZM 2023.

Soil + Drainage Fit

Skirret likes near-neutral soil (pH 5.5-7.5). That's the common-ground band across North Dakota's prairie loam and clay (red river valley) — a soil test confirms it for your site. It will grow across that whole span, but it does best between pH 6 and 6.8 — worth knowing before you decide whether a North Dakota soil test result is a problem or just a number. Drainage matters: this plant wants poorly (saturated >50% of year), well (dry spells). If your North Dakota site is heavier clay or sits in a low spot, raised beds or amendment with compost solve it.

Plant pH requirements: FAO ECOCROP and USDA PLANTS, with the remaining rows from other published sources or Growable Ground compilation. Drainage: FAO ECOCROP, with the remaining rows from other published sources or Growable Ground compilation. North Dakota soil profile from USDA NRCS SSURGO. Site-specific verification: a 30-minute soil test from your local Extension lab.

Before you plant skirret for food

Anything you grow to eat takes up what is in the ground it grows in, so what is on record near you is worth knowing before skirret goes in. What follows is North Dakota’s documented federal record at state scale — a screening signal, not a soil test, and not a statement about any one lot.

Safe to Grow Here?

What the federal record shows across North Dakota — and how to grow with it.

Federal record: High

We checked the federal record across North Dakota20,590 documented sites across 6 of the 9 source types we track.

The most significant on record: 22 Superfund sites. Sites tracked in EPA's Superfund program — from assessment-stage CERCLIS entries to confirmed National Priorities List cleanup sites.

North Dakota carries one of the heavier federal records we track — and that's not a verdict on your yard. Proximity to a documented site is information, not a diagnosis: nothing here says any particular parcel is affected. It does earn one concrete step — before food beds go in the ground, a professional soil test tells you exactly what you're working with, and raised beds with clean imported soil grow well almost anywhere in the meantime.

Know before you grow — the guide

Sources Checked

across North Dakota

Severity Distribution

across North Dakota

High37Moderate16,959Low3,594

Highest-Severity Sites

Superfund · Superfund NPL
PFAS Sampling · PFAS Detected
PFAS Sampling · PFAS Detected
PFAS Sampling · PFAS Detected
PFAS Sampling · PFAS Detected

A note from Gnorman

What an experienced grower watches for around here

In and around North Dakota, Nitrate runs higher than the national average — 15,844 sites across North Dakota. 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).

Sources: EPA, USGS1.8M documented sites tracked nationwide across 9 federal source types.

What Else to Consider for Skirret in North Dakota

Zone compatibility tells you about winter cold survival — but North Dakota growers also need to think about:

Extreme cold (-40F) and short growing season

Persistent wind desiccates plants

Low rainfall in western ND

What to actually do about these — and the constraints that apply to every North Dakota grower, not just skirret — is covered on the North Dakota growing guide.

Timing shifts within North Dakota

Skirret needs about 40 days of frost-free season to complete its cycle. Even Bottineau County — North Dakota’s shortest season at 141 frost-free days — clears that by 101 days, so season length isn’t the constraint anywhere in North Dakota. What varies is your own parcel.

County last-freeze dates and frost-free day counts: NOAA Regional Climate Centers ACIS (1991-2020), county 28°F freeze (earlier than the folk 32°F "last frost"). Skirret's 40-day requirement: USDA PLANTS / Growable Ground plant database (minimum frost-free days). A parcel report resolves your address's own frost dates.

Pollinator + Wildlife Value

Skirret draws honeybees and native bees (moderate value, Growable Ground Plant Database). Planting it near vegetable beds can lift fruit set on neighboring crops. Outdoors, skirret can only work that bloom inside North Dakota's frost window — roughly 157 days, opening after the last 28°F freeze (Apr 30 - May 6) and closing at the first (Oct 4 - Oct 9), per NOAA Regional Climate Centers ACIS, 1991-2020.

North Dakota Cooperative Extension

For North Dakota-specific cultivar recommendations, planting calendars, and pest pressure for skirret, the canonical source is NDSU Extension. Their fact sheets carry the local trial data we can't generalize across 50 states.

Common Questions About Growing Skirret in North Dakota

When can I plant Skirret in North Dakota?

North Dakota's last spring hard freeze (28°F) clears between Apr 30 and May 6, and the first fall hard freeze lands between Oct 4 and Oct 9 (NOAA Regional Climate Centers ACIS, 1991-2020). Time outdoor planting to after the last hard freeze for your specific site — a further two to three weeks for anything tender — and count back from those dates for transplant scheduling.

What hardiness zone is Skirret grown in across North Dakota?

North Dakota spans USDA hardiness zones 3b-4b (USDA ARS PHZM 2023). Skirret carries a range of zones 5-9, so the overlap zones are where outdoor growing is most reliable.

How many frost-free days does a typical North Dakota site have?

A typical North Dakota site sees ~157 frost-free days per year (derived from NOAA Regional Climate Centers ACIS, 1991-2020). Skirret needs 40+ frost-free days, so check whether your local microclimate runs above or below the state average before settling on a planting date.

How should I amend the soil for Skirret in North Dakota?

Skirret prefers pH 5.5-7.5 and poorly (saturated >50% of year), well (dry spells) drainage (FAO ECOCROP). That sits in the common-ground band across North Dakota soils — a 30-minute soil test from a local Extension lab confirms it for your specific site.

Will Skirret actually grow on my specific land in North Dakota?

State-level zone + climate data is a sketch. A Growable Ground parcel report scores skirret against your address's exact soil pH, drainage, sun, and frost-date data drawn from USDA SSURGO, NOAA, and PRISM — not state averages.

Free Report

Check your specific parcel in North Dakota

State-level data is a sketch. Your Growable Ground report scores skirret against your parcel's exact soil, sun, drainage, and frost data — not zone averages.

Three things about your lot that North Dakota skirret averages can't show:

Your soil pHYour frost-free days — North Dakota averages 157Your sun & shade

We read public map data around North Dakota — soil, climate, flood, and parcel records. How we handle your address.

25+ data sources read at your address, not the North Dakota skirret average

Explore More

Explore North Dakota county by county

North Dakota carries 53 counties with their own USDA zone — a sample of the growing pages for skirret there:

Where else skirret grows

Skirret's zone band crosses state lines — these are the states closest to North Dakota in winter climate where it also has a page, plus the far ends of its range. Each one re-answers the question with that state's own record.

More to grow in North Dakota

North Dakota has a growing page for 745 plants — a rotating sample of the rest of the shelf.

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