Yes — Strong Match
leek 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.
Leek in Kentucky — the short answer
Leek in Kentucky: grown in zones 2–11, full sun.
- Plant zones
- 2-11
- Not verified — NC State Extension Gardener Plant Toolbox lists zones 5a–10b
- 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
- 100 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.
Kentucky spans zones 6a-7b, 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 leek 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 parcel report in seconds — read in full free for your first 14 days
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 leek 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 leek (USDA PHZM 2023):
Zone Comparison
Leek Needs
- USDA Zones: 2-11
- Sun: Full Sun
- Mature size: 2.5 ft tallWe haven't confirmed this against a published source yet.
- Picking window: ~60 days of harvestWe haven't confirmed this against a published source yet.
- Drought tolerance: LowWe 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 Leek 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 leek goes out, not when it starts. It is sown under cover about 8 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.
Establishment timing
As a long-lived plant, leek isn't racing the calendar to a harvest date. Plant it in spring once the last hard-freeze window passes so roots settle in through the full season, or in early fall while the soil still holds summer warmth.
Timing tuned to sub-state frost dates — Greenup County, not the statewide average.
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
Leek is grown in zones 2–11, which covers every zone Kentucky contains (6a-7b). It overwinters in the ground only in zone 5 and warmer (NC State Extension Gardener Plant Toolbox). Kentucky's typical season runs ~221 frost-free days against the ~120 leek needs.
Growing degree days
Leek needs ~1500 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
Leek tolerates a wide pH range (pH 4.5-7.5) — 3 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 6 and 6.5 — 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. Drainage need: We haven't confirmed this against a published source yet.
Your land, not the state average
Whether leek is safe to eat from Kentucky soil is a block-by-block question, not a town-wide one — 19,166 documented contamination sites mean levels spike on some parcels and not the one next door. Leek roots to about 19 inches, so it is the top 19 inches under your address that decide what it takes up, so only a test on your address settles it.
Check your parcel → Source: USDA NRCS SSURGO + EPA/state contamination databases.
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 leek 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 leek 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 Leek in Kentucky
The zone range tells you where leek 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
Growing leek here specifically
Leek grows its edible bulb in the soil itself, so on any of Kentucky's 19,166 documented contamination sites it can carry up lead you'd then eat.
Confirm your parcel's lead level before the first crop, and keep leek in raised beds of imported, lab-tested soil, which lower contact with the ground but do not remove it. How to handle it →
What to actually do about these — and the constraints that apply to every Kentucky grower, not just leek — is covered on the Kentucky growing guide.
Timing shifts within Kentucky
Kentucky isn't one climate. In Greenup County, the last hard freeze (28°F) holds until about Apr 13 — roughly 13 days later than the recorded state median — so plant leek to your county's window, not the statewide date.
County last-freeze dates: NOAA Regional Climate Centers ACIS (1991-2020), county 28°F freeze (earlier than the folk 32°F "last frost"). A parcel report resolves your address's own frost dates.
Where in Kentucky Leek Is Zone-Hardy
Leek is rated for USDA zones 2–11. Every one of Kentucky’s 120 counties sits inside that band — from Anderson County at zone 6b to Lyon County at zone 7b — 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 120 counties Kentucky’s winter-low ladder runs from zone 6b in Anderson County to zone 7b in Lyon 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. Greenup County holds its last hard freeze (28°F) until about Apr 13, while Livingston County is clear by Mar 18 — 26 days apart. Set leek 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". Leek’s zone 2–11 band: Not verified — NC State Extension Gardener Plant Toolbox lists zones 5a–10b. A parcel report resolves your address’s own zone and frost dates rather than its county’s.
Pollinator + Wildlife Value
Leek draws honeybees, native bees, and butterflies (moderate value). Planting it near vegetable beds can lift fruit set on neighboring crops. Outdoors, leek 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 Leek
Leek is listed as toxic to dogs, cats (all) at a moderate level. (Source: NC State Extension Gardener Plant Toolbox; Cortinovis & Caloni 2016, Frontiers in Veterinary Science, which reports this plant toxic to dogs and cats.) Most listed plants only cause brief upset — a raised bed or a fenced corner usually keeps curious pets clear. Worth knowing for placement: leek overwinters through Kentucky — its sourced hardiness floor is zone 5 and the state runs no colder than zone 6 — so it stands in the bed year-round, and where you site it is a long-term decision.
Kentucky Cooperative Extension
For Kentucky-specific cultivar recommendations, planting calendars, and pest pressure for leek, 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 Leek native to Kentucky?
No — the USDA PLANTS Database lists Leek 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 Leek in Kentucky
When can I plant Leek 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). Leek is a long-lived planting, so target spring just after your local last hard freeze — or early fall while the soil holds warmth — and let it establish through the season.
What hardiness zone is Leek grown in across Kentucky?
Kentucky spans USDA hardiness zones 6a-7b (USDA ARS PHZM 2023). Leek 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). Leek needs 120+ frost-free days, so check whether your local microclimate runs above or below the state average before settling on a planting date. In cooler counties like Greenup, the freeze-free season runs shorter than the state average, so verify your own county's window.
Is Leek native to Kentucky?
No — the USDA PLANTS Database lists Leek 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 Leek in Kentucky?
Leek tolerates pH 4.5-7.5 and well (dry spells) drainage. We haven't confirmed this against a published source yet. That is a 3-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 Leek actually grow on my specific land in Kentucky?
State-level zone + climate data is a sketch. A Growable Ground parcel report scores leek 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 leek against your land's mapped soil, modelled sun, drainage, and frost data — not zone averages.
Three things about your lot that Kentucky leek 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 leek average
Explore More
Growing guides for leek
Explore Kentucky county by county
Kentucky carries 120 counties with their own USDA zone — a sample of the growing pages for leek there:
Where else leek grows
Leek'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.
Analysis by the Growable Ground research team, grounded in USDA PLANTS, USDA NRCS SSURGO, NOAA Climate Normals (1991-2020), and named Cooperative Extension sources. How we know →
Cite this dataset
Kirchick, M. (2026). Growable Ground Plant Database [Data set]. Zenodo. https://doi.org/10.5281/zenodo.21435643
Licensed CC BY-NC 4.0. DOI 10.5281/zenodo.21435643
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