Yes — Strong Match
whorled milkweed (zones 3-9) covers every zone Ohio contains (5b-7a), so hardiness is not what limits it anywhere in the state.
Whorled Milkweed in Ohio — the short answer
Whorled Milkweed in Ohio: hardy in zones 3–9, full sun, against a state median of ~208 frost-free days.
- Plant zones
- 3-9
- 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
- Ohio zones
- 5b-7a
- USDA PHZM 2023
- Frost window
- Apr 5 - Apr 13 – Oct 31 - Nov 6
- NOAA RCC ACIS 1991-2020, 28°F
- Shortest county season
- 182 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.
Ohio 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 whorled milkweed against your parcel's actual hardiness, soil, and sun.
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Ohio is not one climate
Ohio’s winter-low ladder runs across 88 counties, from zone 6 in Allen County to zone 7 in Scioto County. That is 10°F between the two counties’ average coldest night — the difference between whorled milkweed overwintering in the ground and coming under cover.
The middle half of 88 counties runs 6–6.5 zones, with a median of 6.5 zones — a 1-zone span end to end.
Measured across 88 Ohio 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 Ohio Fits Best
Even within Ohio's zones 5b-7a, county microclimates differ enough to change what thrives. These counties carry the closest zone match for whorled milkweed (USDA PHZM 2023):
Zone Comparison
Whorled Milkweed Needs
- USDA Zones: 3-9
- Sun: Full Sun
- Mature size: 2 ft tall
- Picking window: ~45 days of harvest
- Drought tolerance: High
Ohio Has
- USDA Zones: 5b-7a
- Last Hard Freeze (28°F): Apr 5 - Apr 13
- First Hard Freeze (28°F): Oct 31 - Nov 6
- Annual Rainfall: 34-42 inches
- Common Soils: Glacial till, Clay loam, Silt loam
Plant Zone Range (zones 3-9)
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 Whorled Milkweed in Ohio
The frost window
Across Ohio, the last spring hard freeze (28°F) clears between Apr 5 and Apr 13, and the first fall hard freeze lands between Oct 31 and Nov 6 (NOAA Regional Climate Centers ACIS, 1991-2020). Counting from the latest last freeze to the earliest first freeze, that's a 201-day window you can count on — up to 215 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
Ohio runs as cold as USDA zone 5, and no sourced winter-hardiness floor is on record for whorled milkweed, so this page does not state whether it overwinters here — and gives no fall establishment date on the strength of a guess. Whether whorled milkweed is a permanent planting or a replant-every-spring crop for you turns on your own zone within Ohio; 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.
Soil + Drainage Fit
Whorled Milkweed likes near-neutral soil (pH 5.5-7.5). That's the common-ground band across Ohio's glacial till and clay loam — a soil test confirms it for your site. Drainage matters: this plant wants well (dry spells). If your Ohio 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. Ohio soil profile from USDA NRCS SSURGO. Site-specific verification: a 30-minute soil test from your local Extension lab.
What Else to Consider for Whorled Milkweed in Ohio
Zone compatibility tells you about winter cold survival — but Ohio growers also need to think about:
Heavy clay soils across much of northern Ohio require amendment for drainage
Variable spring weather with late frost risk through mid-May
Japanese beetles and tomato hornworms are common garden pests
Wet springs can delay planting and promote root rot
What to actually do about these — and the constraints that apply to every Ohio grower, not just whorled milkweed — is covered on the Ohio growing guide.
Where in Ohio Whorled Milkweed Is Zone-Hardy
Whorled Milkweed is rated for USDA zones 3–9. Every one of Ohio’s 88 counties sits inside that band — from Allen County at zone 6a to Scioto County at zone 7a — so winter cold is not what decides this plant anywhere in the state. What is left to vary is your own parcel: slope, shelter and cold-air drainage routinely move a site half a zone either way from the county figure.
Across those 88 counties Ohio’s winter-low ladder runs from zone 6a in Allen County to zone 7a in Scioto County — 1 USDA zone of spread, which is 10°F between the two counties’ average coldest night of the year. That is why a statewide hardiness answer is where you start and not where you finish.
The planting window moves with it. Geauga County holds its last hard freeze (28°F) until about Apr 22, while Cuyahoga County is clear by Mar 30 — 23 days apart. Set whorled milkweed out on your county’s date, not the state’s.
County hardiness zones: USDA Plant Hardiness Zone Map (PHZM) 2023, per county. County last-freeze dates: NOAA Regional Climate Centers ACIS (1991-2020), county 28°F killing freeze — earlier than the folk 32°F "last frost". Whorled Milkweed’s zone 3–9 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
Whorled Milkweed draws honeybees, native bees, butterflies, and moths (high value, Growable Ground Plant Database). Planting it near vegetable beds can lift fruit set on neighboring crops. Outdoors, whorled milkweed can only work that bloom inside Ohio's frost window — roughly 208 days, opening after the last 28°F freeze (Apr 5 - Apr 13) and closing at the first (Oct 31 - Nov 6), per NOAA Regional Climate Centers ACIS, 1991-2020.
Ohio Cooperative Extension
For Ohio-specific cultivar recommendations, planting calendars, and pest pressure for whorled milkweed, the canonical source is Ohio State University Extension. Their fact sheets carry the local trial data we can't generalize across 50 states.
Is Whorled Milkweed native to Ohio?
Yes — the USDA PLANTS Database (accessed 2026-07-01) documents Whorled Milkweed as native to Ohio. 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 Whorled Milkweed in Ohio
When can I plant Whorled Milkweed in Ohio?
Ohio's last spring hard freeze (28°F) clears between Apr 5 and Apr 13, and the first fall hard freeze lands between Oct 31 and Nov 6 (NOAA Regional Climate Centers ACIS, 1991-2020). No sourced winter-hardiness floor is on record for Whorled Milkweed, so this page does not state whether it overwinters in Ohio 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 Whorled Milkweed grown in across Ohio?
Ohio spans USDA hardiness zones 5b-7a (USDA ARS PHZM 2023). Whorled Milkweed carries a range of zones 3-9, so the overlap zones are where outdoor growing is most reliable.
How many frost-free days does a typical Ohio site have?
A typical Ohio site sees ~208 frost-free days per year (derived from NOAA Regional Climate Centers ACIS, 1991-2020). Whorled Milkweed 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.
Is Whorled Milkweed native to Ohio?
Yes — the USDA PLANTS Database (accessed 2026-07-01) documents Whorled Milkweed as native to Ohio. Planting it supports the pollinators and wildlife that evolved alongside it.
How should I amend the soil for Whorled Milkweed in Ohio?
Whorled Milkweed prefers pH 5.5-7.5 and well (dry spells) drainage (Growable Ground Plant Database). That sits in the common-ground band across Ohio soils — a 30-minute soil test from a local Extension lab confirms it for your specific site.
Will Whorled Milkweed actually grow on my specific land in Ohio?
State-level zone + climate data is a sketch. A Growable Ground parcel report scores whorled milkweed 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 Ohio
State-level data is a sketch. Your Growable Ground report scores whorled milkweed against your parcel's exact soil, sun, drainage, and frost data — not zone averages.
Three things about your lot that Ohio whorled milkweed averages can't show:
We read public map data around Ohio — soil, climate, flood, and parcel records. How we handle your address.
25+ data sources read at your address, not the Ohio whorled milkweed average
Explore More
Growing guides for whorled milkweed
Explore Ohio county by county
Ohio carries 88 counties with their own USDA zone — a sample of the growing pages for whorled milkweed there:
Where else whorled milkweed grows
Whorled Milkweed's zone band crosses state lines — these are the states closest to Ohio 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 Ohio
Ohio has a growing page for 893 plants — a rotating sample of the rest of the shelf.
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