skirret (Sium sisarum), photographi

Can I Grow Skirret in Kansas?

USDA Zones 5b-7a · Plant zone range 5-9

Yes — Strong Match

skirret (zones 5-9) covers every zone Kansas contains (5b-7a), so hardiness is not what limits it anywhere in the state.

Skirret in Kansas — the short answer

Skirret in Kansas: hardy in zones 5–9, part sun, against a state median of ~208 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
Kansas zones
5b-7a
USDA PHZM 2023
Frost window
Apr 1 - Apr 12 – Oct 25 - Nov 3
NOAA RCC ACIS 1991-2020, 28°F
Shortest county season
177 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.

Kansas spans zones 5b-7a, 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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Kansas is not one climate

A single Kansas answer averages 105 counties whose growing seasons are 54 days apart — from 177 frost-free days in Greeley County to 231 in Crawford County. Which end of that your land sits nearer changes what skirret can finish before the first hard freeze.

177 daysGreeley County231 daysCrawford County

The middle half of 105 counties runs 197216 days, with a median of 208 days — a 54-day span end to end.

Measured across 105 Kansas counties. NOAA Regional Climate Centers ACIS, 1991-2020, county 28°F killing freeze. 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 in Kansas Fits Best

Even within Kansas's zones 5b-7a, county microclimates differ enough to change what thrives. These counties carry the closest zone match for skirret (USDA PHZM 2023):

Zone Comparison

Skirret Needs

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

Kansas Has

  • USDA Zones: 5b-7a
  • Last Hard Freeze (28°F): Apr 1 - Apr 12
  • First Hard Freeze (28°F): Oct 25 - Nov 3
  • Annual Rainfall: 16-42 inches
  • Common Soils: Prairie loam, Silt loam, Clay

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 Kansas

The frost window

Across Kansas, the last spring hard freeze (28°F) clears between Apr 1 and Apr 12, and the first fall hard freeze lands between Oct 25 and Nov 3 (NOAA Regional Climate Centers ACIS, 1991-2020). Counting from the latest last freeze to the earliest first freeze, that's a 196-day window you can count on — up to 216 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 Kansas's late-side last freeze of Apr 12 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 survives winter here. Whether the season is long enough — and warm enough — is a different question.

Frost-free days

Skirret wants 40+ frost-free days; a typical Kansas site sees ~208 (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 Kansas's prairie loam and silt loam — 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 Kansas 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 Kansas 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. Kansas 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 Kansas’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 Kansas — and how to grow with it.

Federal record: High

We checked the federal record across Kansas33,298 documented sites across 8 of the 9 source types we track.

The most significant on record: 146 Superfund sites. Sites tracked in EPA's Superfund program — from assessment-stage CERCLIS entries to confirmed National Priorities List cleanup sites.

Kansas 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.

Severity Distribution

across Kansas

High153Moderate19,485Low13,660

Highest-Severity Sites

29TH & Mead Ground Water Contamination
Superfund · Superfund NPL
57TH and North Broadway Streets Site
Superfund · Superfund NPL
A. E. Van Tebra Land
Mining Sites · Past Producer
Abilene, City of
PFAS Sampling · PFAS Detected
Ace Services
Superfund · Superfund NPL

A note from Gnorman

What an experienced grower watches for around here

In and around Kansas, two things run higher than the national average across Kansas — Nitrate (15,878 sites) and CAFO (485 sites). 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.

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

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

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

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

What Else to Consider for Skirret in Kansas

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

Low rainfall in western KS requires irrigation

Extreme wind and hail during severe storm season

Hot dry summers with 100F+ days

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

Timing shifts within Kansas

Skirret needs about 40 days of frost-free season to complete its cycle. Even Greeley County — Kansas’s shortest season at 177 frost-free days — clears that by 137 days, so season length isn’t the constraint anywhere in Kansas. 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 Kansas's frost window — roughly 208 days, opening after the last 28°F freeze (Apr 1 - Apr 12) and closing at the first (Oct 25 - Nov 3), per NOAA Regional Climate Centers ACIS, 1991-2020.

Kansas Cooperative Extension

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

Common Questions About Growing Skirret in Kansas

When can I plant Skirret in Kansas?

Kansas's last spring hard freeze (28°F) clears between Apr 1 and Apr 12, and the first fall hard freeze lands between Oct 25 and Nov 3 (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 Kansas?

Kansas spans USDA hardiness zones 5b-7a (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 Kansas site have?

A typical Kansas site sees ~208 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 Kansas?

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 Kansas 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 Kansas?

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 Kansas

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 Kansas skirret averages can't show:

Your soil pHYour frost-free days — Kansas averages 208Your sun & shade

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

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

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