Unlikely — Zone Mismatch
canna lily (indica) (zones 7-11) does not overlap with Iowa's zone range (4b-6a). Growing outdoors is unlikely without significant protection.
One zone short — what would close it
Canna Lily Indica is hardy to zone 7, and the warmest ground in Iowa is zone 6 — 1 zone short. Planted in open ground it will not survive a Iowa winter. To grow it here, grow canna lily indica in a hoop house or unheated greenhouse — its modeled 1.5-zone lift covers this gap.
A hoop house or unheated greenhouse is the lift this needs. How a greenhouse changes what you can grow →
Zone math from 7-11 (plant) against 4-6 (Iowa). Lift modeled by crop_engine.GREENHOUSE_ZONE_MODIFIER_BY_SUBTYPE['hoop_house'] (+1.5 zones) via api/fast_sections.py Unlock Engine v2.
Canna Lily Indica in Iowa — the short answer
Canna Lily Indica in Iowa: hardy in zones 7–11, full sun, against a state median of ~189 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
- Iowa zones
- 4b-6a
- USDA PHZM 2023
- Frost window
- Apr 10 - Apr 17 – Oct 18 - Oct 23
- NOAA RCC ACIS 1991-2020, 28°F
- Shortest county season
- 168 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.
Iowa spans zones 4b-6a, 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 canna lily indica 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.
No card required · your full report in seconds
Iowa is not one climate
A single Iowa answer averages 99 counties whose growing seasons are 48 days apart — from 168 frost-free days in Howard County to 216 in Lee County. Which end of that your land sits nearer changes what canna lily indica can finish before the first hard freeze.
The middle half of 99 counties runs 183–197 days, with a median of 189 days — a 48-day span end to end.
Measured across 99 Iowa 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 Canna Lily Indica Stands in Iowa
Canna Lily Indica is rated for zones 7–11 — a cold floor USDA puts at 0 to 10°F. No Iowa 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 Iowa winters, not about canna lily indica.
Below the zone 7 floor
99 counties
- Clayton County · zone 4b
- Howard County · zone 4b
- Winneshiek County · zone 4b
3 of 99 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
Canna Lily Indica Needs
- USDA Zones: 7-11
- Sun: Full Sun
- Picking window: ~60 days of harvest
Iowa Has
- USDA Zones: 4b-6a
- Last Hard Freeze (28°F): Apr 10 - Apr 17
- First Hard Freeze (28°F): Oct 18 - Oct 23
- Annual Rainfall: 26-36 inches
- Common Soils: Prairie loess, Silt loam, Clay loam
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 Canna Lily Indica in Iowa
The frost window
Across Iowa, the last spring hard freeze (28°F) clears between Apr 10 and Apr 17, and the first fall hard freeze lands between Oct 18 and Oct 23 (NOAA Regional Climate Centers ACIS, 1991-2020). Counting from the latest last freeze to the earliest first freeze, that's a 184-day window you can count on — up to 196 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 canna lily indica goes out, not when it starts. It is sown under cover about 8 weeks ahead, so counting back from Iowa's late-side last freeze of Apr 17 is what fixes your sowing date — and a yard that clears frost earlier than the state's late date starts earlier still.
Timing tuned to sub-state frost dates — Howard County, not the statewide average.
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.
Soil + Drainage Fit
Canna Lily Indica tolerates a wide pH range (pH 5-8) — 3 units, acid ground through alkaline — so soil acidity is rarely what limits it in Iowa. A soil test is still worth having, but for what else it tells you about this site, not to clear this plant. It will grow across that whole span, but it does best between pH 5.5 and 7.5 — worth knowing before you decide whether a Iowa soil test result is a problem or just a number. Drainage matters: this plant wants well (dry spells). If your Iowa site is heavier clay or sits in a low spot, raised beds or amendment with compost solve it.
Your land, not the state average
Whether canna lily indica is safe to eat from Iowa soil is a block-by-block question, not a town-wide one — 28,062 documented contamination sites mean levels spike on some parcels and not the one next door. Canna Lily Indica roots to about 59 inches, so it is the top 59 inches under your address that decide what it takes up, so only a test on your address settles it.
Check your parcel → Source: USDA NRCS SSURGO + EPA/state contamination databases.
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. Iowa soil profile from USDA NRCS SSURGO. Site-specific verification: a 30-minute soil test from your local Extension lab.
Before you plant canna lily indica 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 canna lily indica goes in. What follows is Iowa’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 Iowa — and how to grow with it.
We checked the federal record across Iowa — 28,062 documented sites across 8 of the 9 source types we track.
The most significant on record: 122 Superfund sites. Sites tracked in EPA's Superfund program — from assessment-stage CERCLIS entries to confirmed National Priorities List cleanup sites.
Iowa 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.
Sources Checked
across Iowa
Severity Distribution
across Iowa
Highest-Severity Sites
A note from Gnorman
What an experienced grower watches for around here
In and around Iowa, Nitrate runs higher than the national average — 8,028 sites across Iowa. 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, USGS — 1.8M documented sites tracked nationwide across 9 federal source types.
What Else to Consider for Canna Lily Indica in Iowa
Zone compatibility tells you about winter cold survival — but Iowa growers also need to think about:
Cold winters reaching -20F or below
Variable spring weather delays planting
Wind exposure on open prairies desiccates plants
Growing canna lily indica here specifically
Because you eat the root of canna lily indica that sit in the soil, contamination matters more than for most crops — Iowa has 28,062 documented sites, and lead concentrates block by block, not town-wide.
Test your soil for lead first, and raise canna lily indica in clean imported soil if the reading is high. How to handle it →
What to actually do about these — and the constraints that apply to every Iowa grower, not just canna lily indica — is covered on the Iowa growing guide.
Timing shifts within Iowa
Iowa isn't one climate. In Howard County, the last hard freeze (28°F) holds until about Apr 24 — roughly 10 days later than the recorded state median — so plant canna lily indica to your county's window, not the statewide date.
County last-freeze dates: NOAA Regional Climate Centers ACIS (1991-2020), county 28°F freeze (earlier than the folk 32°F "last frost"). A parcel report resolves your address's own frost dates.
Where in Iowa Canna Lily Indica Is Zone-Hardy
Canna Lily Indica is rated for USDA zones 7–11. No Iowa county reaches it. Even Lee County, the state’s mildest winter at zone 6a, sits below the plant’s zone 7 floor — so in open ground this one needs winter protection here, or a container that comes under cover.
Across those 99 counties Iowa’s winter-low ladder runs from zone 4b in Clayton County to zone 6a in Lee County — 1.5 USDA zones of spread, which is 15°F between the two counties’ average coldest night of the year. None of that range reaches the band canna lily indica needs, so here the statewide answer really is the answer.
County hardiness zones: USDA Plant Hardiness Zone Map (PHZM) 2023, per county. Canna Lily Indica’s zone 7–11 band: USDA PLANTS / Growable Ground plant database. A parcel report resolves your address’s own zone and frost dates rather than its county’s.
Pollinator + Wildlife Value
Canna Lily Indica draws hummingbirds and native bees (moderate value, Growable Ground Plant Database). Planting it near vegetable beds can lift fruit set on neighboring crops. Outdoors, canna lily indica can only work that bloom inside Iowa's frost window — roughly 189 days, opening after the last 28°F freeze (Apr 10 - Apr 17) and closing at the first (Oct 18 - Oct 23), per NOAA Regional Climate Centers ACIS, 1991-2020.
Iowa Cooperative Extension
For Iowa-specific cultivar recommendations, planting calendars, and pest pressure for canna lily indica, the canonical source is Iowa State University Extension and Outreach. Their fact sheets carry the local trial data we can't generalize across 50 states.
Common Questions About Growing Canna Lily Indica in Iowa
When can I plant Canna Lily Indica in Iowa?
Iowa's last spring hard freeze (28°F) clears between Apr 10 and Apr 17, and the first fall hard freeze lands between Oct 18 and Oct 23 (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 Canna Lily Indica grown in across Iowa?
Iowa spans USDA hardiness zones 4b-6a (USDA ARS PHZM 2023). Canna Lily Indica 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 Iowa site have?
A typical Iowa site sees ~189 frost-free days per year (derived from NOAA Regional Climate Centers ACIS, 1991-2020). Canna Lily Indica should be matched against that window, so check whether your local microclimate runs above or below the state average before settling on a planting date. In cooler counties like Howard, the freeze-free season runs shorter than the state average, so verify your own county's window.
How should I amend the soil for Canna Lily Indica in Iowa?
Canna Lily Indica tolerates pH 5-8 and well (dry spells) drainage (FAO ECOCROP). That is a 3-unit span, acid ground through alkaline, so pH is rarely what limits this plant on a Iowa site — amend for drainage and organic matter first.
Will Canna Lily Indica actually grow on my specific land in Iowa?
State-level zone + climate data is a sketch. A Growable Ground parcel report scores canna lily indica 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 Iowa
State-level data is a sketch. Your Growable Ground report scores canna lily indica against your parcel's exact soil, sun, drainage, and frost data — not zone averages.
Three things about your lot that Iowa canna lily indica averages can't show:
We read public map data around Iowa — soil, climate, flood, and parcel records. How we handle your address.
25+ data sources read at your address, not the Iowa canna lily indica average
Explore More
Growing guides for canna lily indica
Explore Iowa county by county
Iowa carries 99 counties with their own USDA zone — a sample of the growing pages for canna lily indica there:
Where else canna lily indica grows
Canna Lily Indica's zone band crosses state lines — these are the states closest to Iowa 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 Iowa
Iowa has a growing page for 806 plants — a rotating sample of the rest of the shelf.
Analysis by the Growable Ground research team, grounded in USDA PLANTS, USDA NRCS SSURGO, NOAA Climate Normals (1991-2020), and named Cooperative Extension sources. How we know →
Cite this dataset
Kirchick, M. (2026). Growable Ground Plant Database [Data set]. Zenodo. https://doi.org/10.5281/zenodo.21435643
Licensed CC BY-NC 4.0. DOI 10.5281/zenodo.21435643
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