Yes — Strong Match
snow pea is grown in zones 2-11, which covers every zone Iowa contains (4b-6a). Whether the season is long enough is the question that remains.
Snow Pea in Iowa — the short answer
Snow Pea in Iowa: grown in zones 2–11, full sun, against a state median of ~189 frost-free days.
- Plant zones
- Grown as an annual — see the growing season
- Growing season, not a hardiness zone
- 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
- Days to maturity
- 60 days
- Growable Ground Plant Database
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 snow pea 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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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 snow pea 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 in Iowa Fits Best
Even within Iowa's zones 4b-6a, county microclimates differ enough to change what thrives. These counties carry the closest zone match for snow pea (USDA PHZM 2023):
Zone Comparison
Snow Pea Needs
- USDA Zones: 2-11
- Frost-Free Days: 60+
- Sun: Full SunWe haven't confirmed this against a published source yet.
- Mature size: 5 ft tallWe haven't confirmed this against a published source yet.
- Picking window: ~21 days of harvestWe haven't confirmed this against a published source yet.
- Drought tolerance: LowWe haven't confirmed this against a published source yet.
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 2-11)
Preferred Soil pH
We haven't confirmed this against a published source yet.
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 Snow Pea 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.
Frost tenderness
Snow Pea is frost-tender — its killing temperature is 32°F — so set plants out two to three weeks PAST your local last hard freeze, not on it and not on the state's earliest date. The 28°F marker above is when killing freezes stop, not when light frost does. That is the point where cold damages growing tissue, not a winter-survival floor — an established perennial comes through far colder while dormant, which is what its hardiness zone tells you. We haven't confirmed this against a published source yet.
When to start the seed
Snow Pea is direct-sown where it grows rather than started under cover, so there is no seed-tray head start to bank — Iowa's dates above are the whole calendar for it. That makes the last-freeze date the binding constraint, and a warmer pocket of your own yard is worth more to this crop than it is to a transplanted one.
Days to maturity vs. the window
At 60 days to maturity (Growable Ground Plant Database), counting from the last hard freeze it ripens with 124 days to spare even in Iowa's tightest freeze scenario — room for a later start or a second sowing.
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
Snow Pea is grown in zones 2–11, which covers every zone Iowa contains (4b-6a). We have no sourced winter-survival figure for snow pea, so this page does not say whether it overwinters here. Iowa's typical season runs ~189 frost-free days against the ~60 snow pea needs.
Frost-free days
Snow Pea wants 60+ frost-free days; a typical Iowa site sees ~189 (NOAA Regional Climate Centers ACIS, 1991-2020). That leaves comfortable headroom for succession planting.
Growing degree days
Snow Pea needs ~700 GDD (base 50°F) to ripen. We haven't confirmed this against a published source yet. The state median runs ~2730 GDD (from PRISM 1991-2020 climate normals), so Iowa's typical season clears that easily.
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
Snow Pea tolerates a wide pH range (pH 4.5-8.3) — 3.8 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 — 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, a raised bed lifts the roots above wet ground, or work in compost. pH range, preferred pH and drainage need: We haven't confirmed this against a published source yet.
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 snow pea 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 snow pea 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 — 16,064 documented sites across 7 of the 8 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 of imported, lab-tested soil grow well almost anywhere in the meantime.
Sources Checked
across Iowa
Severity Distribution
across Iowa
Highest-Severity Sites
Know Before You Grow
- •Underground tanks leak petroleum as they age — near a former filling station, test the soil.
- •TRI facilities report what they release. Check the wind — downwind beds catch more of it.
- •Near a brownfield, a raised bed of imported, lab-tested soil lowers contact with the ground; it does not remove it.
Sources: EPA, USGS — 950K documented sites tracked nationwide across 8 federal source types.
What Else to Consider for Snow Pea in Iowa
The zone range tells you where snow pea is grown — 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
What to actually do about these — and the constraints that apply to every Iowa grower, not just snow pea — is covered on the Iowa growing guide.
Timing shifts within Iowa
Snow Pea needs about 60 days of frost-free season to complete its cycle. Even Howard County — Iowa’s shortest season at 168 frost-free days — clears that by 108 days, so season length isn’t the constraint anywhere in Iowa. 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"). Snow Pea's 60-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
Snow Pea draws honeybees (low value). Planting it near vegetable beds can lift fruit set on neighboring crops. Outdoors, snow pea 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. Pollinator value: We haven't confirmed this against a published source yet.
Iowa Cooperative Extension
For Iowa-specific cultivar recommendations, planting calendars, and pest pressure for snow pea, 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 Snow Pea in Iowa
When can I plant Snow Pea 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.
Can Snow Pea mature before first frost in Iowa?
Yes — Snow Pea matures in 60 days (Growable Ground Plant Database), and Iowa's dependable hard-freeze-free window runs 184 days (NOAA Regional Climate Centers ACIS, 1991-2020), leaving 124 days of margin. Plant once the last hard freeze has passed — two to three weeks later for anything tender — and it ripens ahead of the first fall freeze.
What hardiness zone is Snow Pea grown in across Iowa?
Iowa spans USDA hardiness zones 4b-6a (USDA ARS PHZM 2023). Snow Pea carries a range of zones 2-11, 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). Snow Pea needs 60+ 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 Snow Pea in Iowa?
Snow Pea tolerates pH 4.5-8.3 and well (dry spells) drainage. We haven't confirmed this against a published source yet. That is a 3.8-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 Snow Pea actually grow on my specific land in Iowa?
State-level zone + climate data is a sketch. A Growable Ground parcel report scores snow pea against your address's mapped 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 snow pea against your land's mapped soil, modelled sun, drainage, and frost data — not zone averages.
Three things about your lot that Iowa snow pea 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 snow pea average
Explore More
Growing guides for snow pea
Explore Iowa county by county
Iowa carries 99 counties with their own USDA zone — a sample of the growing pages for snow pea there:
Where else snow pea grows
Snow Pea'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 810 plants — a rotating sample of the rest of the shelf.
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