Conditional — Some Areas
cast iron plant (zones 7-11) reaches only part of Kansas (5b-7a): zone 7 are in range, so where you are in the state decides it.
Cast Iron Plant in Kansas — the short answer
Cast Iron Plant in Kansas: hardy in zones 7–11, shade, against a state median of ~208 frost-free days.
- Plant zones
- 7-11
- 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.
Your yard isn't the whole zone.
Kansas spans zones 5b-7a, but your yard sits in exactly one — and slope, tree cover, and cold-air pockets nudge it further. Enter your address and we'll score cast iron plant against your parcel's actual hardiness, soil, and sun.
We read public map data for this spot — soil, climate, flood, and parcel records. How we handle your address.
No card required · your full report in seconds
Kansas is not one climate
Kansas’s winter-low ladder runs across 105 counties, from zone 6 in Atchison County to zone 7 in Wilson County. That is 10°F between the two counties’ average coldest night — the difference between cast iron plant overwintering in the ground and coming under cover.
The middle half of 105 counties runs 6–6.5 zones, with a median of 6.5 zones — a 1-zone span end to end.
Measured across 105 Kansas 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 in Kansas Fits Best
Cast Iron Plant is rated for zones 7–11 — a cold floor USDA puts at 0 to 10°F. Against Kansas’s 105 counties that band holds in 16 of them, and the line runs at Barber County (zone 7a), the coldest county still inside it.
Inside zones 7–11
16 counties
- Bourbon County · zone 7a
- Butler County · zone 7a
- Chautauqua County · zone 7a
3 of 16 shown
Below the zone 7 floor
89 counties
- Atchison County · zone 6a
- Brown County · zone 6a
- Cheyenne County · zone 6a
3 of 89 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.
Even within Kansas's zones 5b-7a, county microclimates differ enough to change what thrives. These counties carry the closest zone match for cast iron plant (USDA PHZM 2023):
Zone Comparison
Cast Iron Plant Needs
- USDA Zones: 7-11
- Frost-Free Days: 120+
- Sun: Shade
- Mature size: 2 ft tall
- Drought tolerance: High
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 7-11)
Preferred Soil pH
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 Cast Iron Plant 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.
Winter standing
Kansas runs as cold as USDA zone 5, and no sourced winter-hardiness floor is on record for cast iron plant, so this page does not state whether it overwinters here — and gives no fall establishment date on the strength of a guess. Whether cast iron plant is a permanent planting or a replant-every-spring crop for you turns on your own zone within Kansas; check its hardiness range against that before treating it as long-lived ground.
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 cast iron plant survives winter in part of Kansas, not across all of it. Whether the season is long enough — and warm enough — is a different question.
Frost-free days
Cast Iron Plant wants 120+ 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
Cast Iron Plant likes near-neutral soil (pH 5.5-7). 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 5.5 and 6.5 — worth knowing before you decide whether a Kansas soil test result is a problem or just a number. Drainage matters: this plant wants 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.
What Else to Consider for Cast Iron Plant 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 cast iron plant — is covered on the Kansas growing guide.
Timing shifts within Kansas
Cast Iron Plant needs about 120 days of frost-free season to complete its cycle. Even Greeley County — Kansas’s shortest season at 177 frost-free days — clears that by 57 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"). Cast Iron Plant's 120-day requirement: USDA PLANTS / Growable Ground plant database (minimum frost-free days). A parcel report resolves your address's own frost dates.
Kansas Cooperative Extension
For Kansas-specific cultivar recommendations, planting calendars, and pest pressure for cast iron plant, the canonical source is K-State Research and Extension. Their fact sheets carry the local trial data we can't generalize across 50 states.
Is Cast Iron Plant native to Kansas?
No — the USDA PLANTS Database lists Cast Iron Plant as introduced rather than native in the Lower 48, so it is not part of Kansas's native flora. It grows here as a garden plant; pairing it with a few Kansas natives keeps local pollinators fed too.
Looking for plants that belong here? The Kansas growing guide lists USDA-documented natives for the state.
Native-range data: USDA PLANTS Database state-distribution records, accessed 2026-07-01.
Common Questions About Growing Cast Iron Plant in Kansas
When can I plant Cast Iron Plant 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). No sourced winter-hardiness floor is on record for Cast Iron Plant, so this page does not state whether it overwinters in Kansas and publishes no fall establishment date for it — check its hardiness range against your own zone before treating it as a permanent planting.
What hardiness zone is Cast Iron Plant grown in across Kansas?
Kansas spans USDA hardiness zones 5b-7a (USDA ARS PHZM 2023). Cast Iron Plant carries a range of zones 7-11, 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). Cast Iron Plant needs 120+ frost-free days, so check whether your local microclimate runs above or below the state average before settling on a planting date.
Is Cast Iron Plant native to Kansas?
No — the USDA PLANTS Database lists Cast Iron Plant as introduced rather than native in the Lower 48, so it is not part of Kansas's native flora. It grows here as a garden plant; pairing it with a few Kansas natives keeps local pollinators fed too.
How should I amend the soil for Cast Iron Plant in Kansas?
Cast Iron Plant prefers pH 5.5-7 and well (dry spells) drainage (Growable Ground Plant Database). 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 Cast Iron Plant actually grow on my specific land in Kansas?
State-level zone + climate data is a sketch. A Growable Ground parcel report scores cast iron plant against your address's exact soil pH, drainage, sun, and frost-date data drawn from USDA SSURGO, NOAA, and PRISM — not state averages.
Check your specific parcel in Kansas
State-level data is a sketch. Your Growable Ground report scores cast iron plant against your parcel's exact soil, sun, drainage, and frost data — not zone averages.
Three things about your lot that Kansas cast iron plant averages can't show:
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 cast iron plant average
Explore More
Growing guides for cast iron plant
Explore Kansas county by county
Kansas carries 105 counties with their own USDA zone — a sample of the growing pages for cast iron plant there:
Where else cast iron plant grows
Cast Iron Plant's zone band crosses state lines — these are the states closest to Kansas 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 Kansas
Kansas has a growing page for 893 plants — a rotating sample of the rest of the shelf.
Last updated: