Yes — Strong Match
mulberry (zones 4-8) covers every zone Iowa contains (4b-6a), so hardiness is not what limits it anywhere in the state.
Mulberry in Iowa — the short answer
Mulberry in Iowa: hardy in zones 4–8, full sun, against a state median of ~189 frost-free days.
- Plant zones
- 4-8
- 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
- Days to maturity
- 1460 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 sits in exactly one — and slope, tree cover, and cold-air pockets nudge it further. Enter your address and we'll score mulberry 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
Iowa is not one climate
Iowa’s winter-low ladder runs across 99 counties, from zone 4.5 in Clayton County to zone 6 in Lee County. That is 15°F between the two counties’ average coldest night — the difference between mulberry overwintering in the ground and coming under cover.
The middle half of 99 counties runs 5–5.5 zones, with a median of 5 zones — a 1.5-zone span end to end.
Measured across 99 Iowa 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 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 mulberry (USDA PHZM 2023):
Zone Comparison
Mulberry Needs
- USDA Zones: 4-8
- Frost-Free Days: 240+
- Sun: Full Sun
- Mature size: 70 ft tall
- Picking window: ~30 days of harvest
- Drought tolerance: Medium
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 4-8)
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 Mulberry 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.
Winter standing
Iowa runs as cold as USDA zone 4, and no sourced winter-hardiness floor is on record for mulberry, so this page does not state whether it overwinters here — and gives no fall establishment date on the strength of a guess. Whether mulberry is a permanent planting or a replant-every-spring crop for you turns on your own zone within Iowa; 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 mulberry survives winter here. Whether the season is long enough — and warm enough — is a different question.
Frost-free days
Mulberry wants 240+ frost-free days; a typical Iowa site sees ~189 (NOAA Regional Climate Centers ACIS, 1991-2020) — 51 days short of what it needs. A typical Iowa season does not carry this crop to harvest outdoors, and a gap that size is not one an earlier sowing date or a faster cultivar closes; growing it here means growing it under cover.
Growing degree days
Mulberry needs ~1800 GDD (base 50°F) to ripen. The state median runs ~2730 GDD (from PRISM 1991-2020 climate normals), so Iowa's typical season clears that easily.
Chill hours
Mulberry requires ~600 chill hours (32-45°F dormancy window). Iowa typically banks ~2500 chill hours per winter (from PRISM 1991-2020 climate normals), which keeps this plant on track.
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
Mulberry 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 — 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.
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 mulberry 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 mulberry 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.
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 Mulberry 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
What to actually do about these — and the constraints that apply to every Iowa grower, not just mulberry — is covered on the Iowa growing guide.
Timing shifts within Iowa
Mulberry needs about 240 days of frost-free season to complete its cycle. No Iowa county gives it that outdoors: even Lee County, the state’s longest season at 216 frost-free days, falls 24 days short — so it needs transplants, a short-season variety, or covered growing.
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"). Mulberry's 240-day requirement: USDA PLANTS / Growable Ground plant database (minimum frost-free days). A parcel report resolves your address's own frost dates.
Iowa Cooperative Extension
For Iowa-specific cultivar recommendations, planting calendars, and pest pressure for mulberry, 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.
Is Mulberry native to Iowa?
Yes — the USDA PLANTS Database (accessed 2026-07-01) documents Mulberry as native to Iowa. Planting it supports the pollinators and wildlife that evolved alongside it.
Native-range data: USDA PLANTS Database state-distribution records, accessed 2026-07-01.
Common Questions About Growing Mulberry in Iowa
When can I plant Mulberry 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). No sourced winter-hardiness floor is on record for Mulberry, so this page does not state whether it overwinters in Iowa 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 Mulberry grown in across Iowa?
Iowa spans USDA hardiness zones 4b-6a (USDA ARS PHZM 2023). Mulberry carries a range of zones 4-8, 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). Mulberry needs 240+ frost-free days, so check whether your local microclimate runs above or below the state average before settling on a planting date.
Is Mulberry native to Iowa?
Yes — the USDA PLANTS Database (accessed 2026-07-01) documents Mulberry as native to Iowa. Planting it supports the pollinators and wildlife that evolved alongside it.
How should I amend the soil for Mulberry in Iowa?
Mulberry 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 Mulberry actually grow on my specific land in Iowa?
State-level zone + climate data is a sketch. A Growable Ground parcel report scores mulberry 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 mulberry against your parcel's exact soil, sun, drainage, and frost data — not zone averages.
Three things about your lot that Iowa mulberry 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 mulberry average
Explore More
Growing guides for mulberry
Last updated: