Yes — Strong Match
calendula is grown in zones 2-11, which covers every zone Kentucky contains (6a-7b). Whether the season is long enough is the question that remains.
Calendula in Kentucky — the short answer
Calendula in Kentucky: grown in zones 2–11, full sun, against a state median of ~221 frost-free days.
- Plant zones
- Grown as an annual — see the growing season
- Growing season, not a hardiness zone
- Kentucky zones
- 6a-7b
- USDA PHZM 2023
- Frost window
- Mar 27 - Apr 2 – Nov 4 - Nov 10
- NOAA RCC ACIS 1991-2020, 28°F
- Shortest county season
- 195 days
- NOAA Regional Climate Centers ACIS, 1991-2020, county 28°F killing freeze
- Days to maturity
- 55 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.
Calendula is grown as an annual, so your winter zone isn't the deciding factor — your frost-free window is. A typical Kentucky site runs ~221 frost-free days, but that is a state median, not your yard: slope, trees, and low spots move the last-frost date across a single parcel. Enter your address and we'll score calendula against your land's actual frost dates, sun, and soil.
We read public map data for this spot — soil, climate, flood, and parcel records. How we handle your address.
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Kentucky is not one climate
A single Kentucky answer averages 120 counties whose growing seasons are 50 days apart — from 195 frost-free days in Greenup County to 245 in Jefferson County. Which end of that your land sits nearer changes what calendula can finish before the first hard freeze.
The middle half of 120 counties runs 216–227 days, with a median of 221 days — a 50-day span end to end.
Measured across 120 Kentucky 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 Kentucky Fits Best
Even within Kentucky's zones 6a-7b, county microclimates differ enough to change what thrives. These counties carry the closest zone match for calendula (USDA PHZM 2023):
Zone Comparison
Calendula Needs
- USDA Zones: 2-11
- Frost-Free Days: 120+
- Sun: Full Sun
- Mature size: 2 ft tallWe haven't confirmed this against a published source yet.
- Picking window: ~90 days of harvestWe haven't confirmed this against a published source yet.
- Drought tolerance: MediumWe haven't confirmed this against a published source yet.
Kentucky Has
- USDA Zones: 6a-7b
- Last Hard Freeze (28°F): Mar 27 - Apr 2
- First Hard Freeze (28°F): Nov 4 - Nov 10
- Annual Rainfall: 42-52 inches
- Common Soils: Silt loam, Clay loam, Limestone-derived
Plant Zone Range (zones 2-11)
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 Calendula in Kentucky
The frost window
Across Kentucky, the last spring hard freeze (28°F) clears between Mar 27 and Apr 2, and the first fall hard freeze lands between Nov 4 and Nov 10 (NOAA Regional Climate Centers ACIS, 1991-2020). Counting from the latest last freeze to the earliest first freeze, that's a 216-day window you can count on — up to 228 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 calendula goes out, not when it starts. It is sown under cover about 6 weeks ahead, so counting back from Kentucky's late-side last freeze of Apr 2 is what fixes your sowing date — and a yard that clears frost earlier than the state's late date starts earlier still.
Days to maturity vs. the window
At 55 days to maturity (Growable Ground Plant Database), counting from the last hard freeze it ripens with 161 days to spare even in Kentucky'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
Calendula is grown in zones 2–11, which covers every zone Kentucky contains (6a-7b). It is grown as a summer crop, so season length decides it here. Kentucky's typical season runs ~221 frost-free days against the ~120 calendula needs.
Frost-free days
Calendula wants 120+ frost-free days; a typical Kentucky site sees ~221 (NOAA Regional Climate Centers ACIS, 1991-2020). That leaves comfortable headroom for succession planting.
Growing degree days
Calendula needs ~900 GDD (base 50°F) to ripen. We haven't confirmed this against a published source yet. The state median runs ~3689 GDD (from PRISM 1991-2020 climate normals), so Kentucky'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
Calendula 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 Kentucky. 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 Kentucky soil test result is a problem or just a number. Drainage matters: this plant wants well (dry spells). If your Kentucky site is heavier clay or sits in a low spot, a raised bed lifts the roots above wet ground, or work in compost.
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. Kentucky soil profile from USDA NRCS SSURGO. Site-specific verification: a 30-minute soil test from your local Extension lab.
Before you plant calendula 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 calendula goes in. What follows is Kentucky’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 Kentucky — and how to grow with it.
We checked the federal record across Kentucky — 19,166 documented sites across 7 of the 8 source types we track.
The most significant on record: 219 Superfund sites. Sites tracked in EPA's Superfund program — from assessment-stage CERCLIS entries to confirmed National Priorities List cleanup sites.
Kentucky 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 Kentucky
Severity Distribution
across Kentucky
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 Calendula in Kentucky
The zone range tells you where calendula is grown — but Kentucky growers also need to think about:
Heavy clay soils in the Bluegrass region
High humidity promotes fungal diseases
Karst topography creates drainage unpredictability
What to actually do about these — and the constraints that apply to every Kentucky grower, not just calendula — is covered on the Kentucky growing guide.
Timing shifts within Kentucky
Calendula needs about 120 days of frost-free season to complete its cycle. Even Greenup County — Kentucky’s shortest season at 195 frost-free days — clears that by 75 days, so season length isn’t the constraint anywhere in Kentucky. 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"). Calendula's 120-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
Calendula draws honeybees, native bees, and butterflies (moderate value). Planting it near vegetable beds can lift fruit set on neighboring crops. Outdoors, calendula can only work that bloom inside Kentucky's frost window — roughly 221 days, opening after the last 28°F freeze (Mar 27 - Apr 2) and closing at the first (Nov 4 - Nov 10), per NOAA Regional Climate Centers ACIS, 1991-2020. Pollinator value: We haven't confirmed this against a published source yet.
Good to Know Before You Plant Calendula
Listed as non-toxic to dogs and cats by a source we can't cite. We haven't confirmed this against a published source yet.
Kentucky Cooperative Extension
For Kentucky-specific cultivar recommendations, planting calendars, and pest pressure for calendula, the canonical source is University of Kentucky Cooperative Extension. Their fact sheets carry the local trial data we can't generalize across 50 states.
Is Calendula native to Kentucky?
No — the USDA PLANTS Database lists Calendula as introduced rather than native in the Lower 48, so it is not part of Kentucky's native flora. It grows here as a garden plant; pairing it with a few Kentucky natives keeps local pollinators fed too.
Looking for plants that belong here? The Kentucky growing guide lists plants that USDA PLANTS records growing in Kentucky and that Kew and NatureServe Explorer both list in its native range, leaving out any that NatureServe flags as exotic there or that our audit holds.
State records: USDA PLANTS Database state-distribution data (presence, not state-level nativity), accessed 2026-10-19.
Common Questions About Growing Calendula in Kentucky
When can I plant Calendula in Kentucky?
Kentucky's last spring hard freeze (28°F) clears between Mar 27 and Apr 2, and the first fall hard freeze lands between Nov 4 and Nov 10 (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 Calendula mature before first frost in Kentucky?
Yes — Calendula matures in 55 days (Growable Ground Plant Database), and Kentucky's dependable hard-freeze-free window runs 216 days (NOAA Regional Climate Centers ACIS, 1991-2020), leaving 161 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 Calendula grown in across Kentucky?
Kentucky spans USDA hardiness zones 6a-7b (USDA ARS PHZM 2023). Calendula 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 Kentucky site have?
A typical Kentucky site sees ~221 frost-free days per year (derived from NOAA Regional Climate Centers ACIS, 1991-2020). Calendula needs 120+ frost-free days, so check whether your local microclimate runs above or below the state average before settling on a planting date.
Is Calendula native to Kentucky?
No — the USDA PLANTS Database lists Calendula as introduced rather than native in the Lower 48, so it is not part of Kentucky's native flora. It grows here as a garden plant; pairing it with a few Kentucky natives keeps local pollinators fed too.
How should I amend the soil for Calendula in Kentucky?
Calendula tolerates pH 4.5-8.3 and well (dry spells) drainage (FAO ECOCROP). That is a 3.8-unit span, acid ground through alkaline, so pH is rarely what limits this plant on a Kentucky site — amend for drainage and organic matter first.
Will Calendula actually grow on my specific land in Kentucky?
State-level zone + climate data is a sketch. A Growable Ground parcel report scores calendula 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 Kentucky
State-level data is a sketch. Your Growable Ground report scores calendula against your land's mapped soil, modelled sun, drainage, and frost data — not zone averages.
Three things about your lot that Kentucky calendula averages can't show:
We read public map data around Kentucky — soil, climate, flood, and parcel records. How we handle your address.
25+ data sources read at your address, not the Kentucky calendula average
Explore More
Growing guides for calendula
Explore Kentucky county by county
Kentucky carries 120 counties with their own USDA zone — a sample of the growing pages for calendula there:
Where else calendula grows
Calendula's zone band crosses state lines — these are the states closest to Kentucky 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 Kentucky
Kentucky has a growing page for 889 plants — a rotating sample of the rest of the shelf.
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