Can I Grow Hollyhock in Ohio?

USDA Zones 5b-7a · Plant zone range 5-9

Yes — Strong Match

hollyhock (zones 5-9) covers every zone Ohio contains (5b-7a), so hardiness is not what limits it anywhere in the state.

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Your yard isn't the whole zone.

Ohio spans zones 5b-7a, 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 hollyhock against your land's actual soil, sun, and frost.

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Zone Comparison

Hollyhock Needs

  • USDA Zones: 5-9
  • Sun: Full Sun
  • Mature size: 6 ft tall
  • Picking window: ~45 days of harvest
  • Drought tolerance: Medium

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 5-9)

5a
9b
3a (Cold)13b (Hot)

Plant data: USDA PLANTS Database / Growable Ground plant catalog. State data: USDA ARS PHZM 2023, NOAA Climate Normals, NRCS SSURGO.

When to Plant Hollyhock 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.

When to start the seed

Those dates are when hollyhock goes out, not when it starts. It is sown under cover about 8 weeks ahead, so counting back from Ohio's late-side last freeze of Apr 13 is what fixes your sowing date — and a yard that clears frost earlier than the state's late date starts earlier still.

Frost window: NOAA Climate Normals 1991-2020. Plant timing fields: USDA PLANTS Database. Your site's own frost dates can run earlier or later than the state range — a parcel report pins them down.

Soil + Drainage Fit

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 and drainage requirements from USDA PLANTS Database. Ohio soil profile from USDA NRCS SSURGO. Site-specific verification: a 30-minute soil test from your local Extension lab.

Hollyhock in Ohio — Quick Answer

  • Verdict: Yes — Strong Match
  • Plant Zones: 5-9 (USDA PLANTS Database)
  • State Zones: 5b-7a (USDA ARS PHZM 2023)
  • Growing Season: 28°F hard freezes about Apr 5 - Apr 13 to Oct 31 - Nov 6 (NOAA Regional Climate Centers ACIS, 1991-2020)

What Else to Consider for Hollyhock 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 hollyhock — is covered on the Ohio growing guide.

Where in Ohio Hollyhock Is Zone-Hardy

Hollyhock is rated for USDA zones 59. 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 hollyhock 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". Hollyhock’s zone 59 band: USDA PLANTS / Growable Ground plant database. A parcel report resolves your address’s own zone and frost dates rather than its county’s.

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 hollyhock (USDA PHZM 2023):

Pollinator + Wildlife Value

Hollyhock draws honeybees, native bees, butterflies, and hummingbirds (high value, Growable Ground Plant Database). Planting it near vegetable beds can lift fruit set on neighboring crops. Outdoors, hollyhock 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 hollyhock, the canonical source is Ohio State University Extension. Their fact sheets carry the local trial data we can't generalize across 50 states.

Is Hollyhock native to Ohio?

No — the USDA PLANTS Database lists Hollyhock as introduced rather than native in the Lower 48, so it is not part of Ohio's native flora. It grows here as a garden plant; pairing it with a few Ohio natives keeps local pollinators fed too.

Looking for plants that belong here? The Ohio growing guide lists USDA-documented natives for the state.

Native-range data: USDA PLANTS Database state-distribution records, accessed 2026-07-01.

What pests threaten hollyhock in Ohio?

Japanese beetle is documented in Ohio and will find hollyhock, but it is manageable here. What an experienced grower watches for, and does:

Japanese beetle

Japanese beetle

Worth watching

This is on the University of Minnesota's list of Japanese beetle preferred plants — but their read is that fruits, vegetables and herbs tolerate limited leaf feeding, and that in most cases the damage is cosmetic and will not kill the plant.

What to do: Protect it only through the few peak weeks: handpick into soapy water in the cool of morning, harvest regularly through July and August to take the feeding pressure off the edible parts, and keep the plant well watered — a vigorous plant outgrows feeding that looks worse than it is. Do not hang a beetle trap.

Documented range: states listed as Japanese-beetle infested · University of Minnesota Extension, National Plant Board

The full japanese beetle playbook

Only pests whose documented range and host relationship both trace to a primary source appear here — so a quiet section means we have nothing sourced to tell you, not that your garden is pest-free.

Common Questions About Growing Hollyhock in Ohio

When can I plant Hollyhock 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). 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 Hollyhock grown in across Ohio?

Ohio spans USDA hardiness zones 5b-7a (USDA ARS PHZM 2023). Hollyhock carries a range of zones 5-9, 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). Hollyhock 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 Hollyhock native to Ohio?

No — the USDA PLANTS Database lists Hollyhock as introduced rather than native in the Lower 48, so it is not part of Ohio's native flora. It grows here as a garden plant; pairing it with a few Ohio natives keeps local pollinators fed too.

Will Hollyhock actually grow on my specific land in Ohio?

State-level zone + climate data is a sketch. A Growable Ground parcel report scores hollyhock against your address's exact soil pH, drainage, sun, and frost-date data drawn from USDA SSURGO, NOAA, and PRISM — not state averages.

Free Report

Check your specific parcel in Ohio

State-level data is a sketch. Your Growable Ground report scores hollyhock against your parcel's exact soil, sun, drainage, and frost data — not zone averages.

Three things about your lot that Ohio hollyhock averages can't show:

Your soil pHYour frost-free days — Ohio averages 208Your sun & shade

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 hollyhock average

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