Yes — Strong Match
hollyhock (zones 5-9) covers every zone Connecticut contains (6a-7b), so hardiness is not what limits it anywhere in the state.
Your yard isn't the whole zone.
Connecticut spans zones 6a-7b, 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
Connecticut Has
- USDA Zones: 6a-7b
- Last Hard Freeze (28°F): Mar 31 - Apr 11
- First Hard Freeze (28°F): Oct 30 - Nov 3
- Annual Rainfall: 44-52 inches
- Common Soils: Glacial till, Sandy loam, River valley silt
Plant Zone Range (zones 5-9)
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 Connecticut
The frost window
Across Connecticut, the last spring hard freeze (28°F) clears between Mar 31 and Apr 11, and the first fall hard freeze lands between Oct 30 and Nov 3 (NOAA Regional Climate Centers ACIS, 1991-2020). Counting from the latest last freeze to the earliest first freeze, that's a 202-day window you can count on — up to 217 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 Connecticut's late-side last freeze of Apr 11 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 Connecticut 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. Connecticut soil profile from USDA NRCS SSURGO. Site-specific verification: a 30-minute soil test from your local Extension lab.
Hollyhock in Connecticut — Quick Answer
- Verdict: Yes — Strong Match
- Plant Zones: 5-9 (USDA PLANTS Database)
- State Zones: 6a-7b (USDA ARS PHZM 2023)
- Growing Season: 28°F hard freezes about Mar 31 - Apr 11 to Oct 30 - Nov 3 (NOAA Regional Climate Centers ACIS, 1991-2020)
What Else to Consider for Hollyhock in Connecticut
Zone compatibility tells you about winter cold survival — but Connecticut growers also need to think about:
Rocky glacial soils require clearing and amendment
Short growing season in northern hills
Deer pressure is high in suburban areas
What to actually do about these — and the constraints that apply to every Connecticut grower, not just hollyhock — is covered on the Connecticut growing guide.
Where in Connecticut Hollyhock Is Zone-Hardy
Hollyhock is rated for USDA zones 5–9. Every one of Connecticut’s 9 counties sits inside that band — from Northwest Hills County at zone 6a to South Central Connecticut 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 9 counties Connecticut’s winter-low ladder runs from zone 6a in Northwest Hills County to zone 7a in South Central Connecticut 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. Northwest Hills County holds its last hard freeze (28°F) until about Apr 19, while Greater Bridgeport County is clear by Mar 27 — 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 5–9 band: USDA PLANTS / Growable Ground plant database. A parcel report resolves your address’s own zone and frost dates rather than its county’s.
Where in Connecticut Fits Best
Even within Connecticut's zones 6a-7b, 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 Connecticut's frost window — roughly 207 days, opening after the last 28°F freeze (Mar 31 - Apr 11) and closing at the first (Oct 30 - Nov 3), per NOAA Regional Climate Centers ACIS, 1991-2020.
Connecticut Cooperative Extension
For Connecticut-specific cultivar recommendations, planting calendars, and pest pressure for hollyhock, the canonical source is UConn Extension. Their fact sheets carry the local trial data we can't generalize across 50 states.
Is Hollyhock native to Connecticut?
No — the USDA PLANTS Database lists Hollyhock as introduced rather than native in the Lower 48, so it is not part of Connecticut's native flora. It grows here as a garden plant; pairing it with a few Connecticut natives keeps local pollinators fed too.
Looking for plants that belong here? The Connecticut 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 Connecticut?
Japanese beetle is documented in Connecticut and will find hollyhock, but it is manageable here. What an experienced grower watches for, and does:
Japanese beetle
Worth watchingThis 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
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 Connecticut
When can I plant Hollyhock in Connecticut?
Connecticut's last spring hard freeze (28°F) clears between Mar 31 and Apr 11, and the first fall hard freeze lands between Oct 30 and Nov 3 (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 Connecticut?
Connecticut spans USDA hardiness zones 6a-7b (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 Connecticut site have?
A typical Connecticut site sees ~207 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 Connecticut?
No — the USDA PLANTS Database lists Hollyhock as introduced rather than native in the Lower 48, so it is not part of Connecticut's native flora. It grows here as a garden plant; pairing it with a few Connecticut natives keeps local pollinators fed too.
Will Hollyhock actually grow on my specific land in Connecticut?
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.
Check your specific parcel in Connecticut
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 Connecticut hollyhock averages can't show:
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Growing guides for hollyhock
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