Yes — Strong Match
ajuga (zones 5-11) covers every zone Kentucky contains (6a-7b), so hardiness is not what limits it anywhere in the state.
Ajuga in Kentucky — the short answer
Ajuga in Kentucky: hardy in zones 5–11, part sun, against a state median of ~221 frost-free days.
- Plant zones
- 5-11
- 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
- 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
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 ajuga against your parcel's actual hardiness, soil, and sun.
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Kentucky is not one climate
Kentucky’s winter-low ladder runs across 120 counties, from zone 6.5 in Anderson County to zone 7.5 in Lyon County. That is 10°F between the two counties’ average coldest night — the difference between ajuga overwintering in the ground and coming under cover.
The middle half of 120 counties runs 6.5–7 zones, with a median of 7 zones — a 1-zone span end to end.
Measured across 120 Kentucky 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 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 ajuga (USDA PHZM 2023):
Zone Comparison
Ajuga Needs
- USDA Zones: 5-11
- Sun: Part Sun
- Mature size: 6 in tall
- Drought tolerance: Medium
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 5-11)
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 Ajuga 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.
Winter standing
Kentucky runs as cold as USDA zone 6, and no sourced winter-hardiness floor is on record for ajuga, so this page does not state whether it overwinters here — and gives no fall establishment date on the strength of a guess. Whether ajuga is a permanent planting or a replant-every-spring crop for you turns on your own zone within Kentucky; check its hardiness range against that before treating it as long-lived ground.
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.
Soil + Drainage Fit
Ajuga likes near-neutral soil (pH 5.5-7.5). That's the common-ground band across Kentucky's silt loam and clay loam — a soil test confirms it for your site. Drainage matters: this plant wants well (dry spells). If your Kentucky site is heavier clay or sits in a low spot, raised beds or amendment with compost solve it.
Your land, not the state average
Kentucky's soils run mostly silt loam, but SSURGO maps the series, texture, and drainage under your exact parcel. What matters for ajuga is the horizon its roots actually work, not the surface. That map unit, not the state average, decides how ajuga performs.
Check your parcel → Source: USDA NRCS SSURGO.
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.
What Else to Consider for Ajuga in Kentucky
Zone compatibility tells you about winter cold survival — 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 ajuga here specifically
Kentucky's soils run mostly silt loam (Alfisols), and whether that suits ajuga's pH 5.5–7.5 preference comes down to your exact parcel, not the statewide picture.
Pull your parcel's SSURGO map unit, test pH, and amend toward ajuga's 5.5–7.5 target before planting. How to handle it →
What to actually do about these — and the constraints that apply to every Kentucky grower, not just ajuga — 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 ajuga 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 Ajuga Is Zone-Hardy
Ajuga is rated for USDA zones 5–11. 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 ajuga 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". Ajuga’s zone 5–11 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
Ajuga draws honeybees and native bees (moderate value, Growable Ground Plant Database). Planting it near vegetable beds can lift fruit set on neighboring crops. Outdoors, ajuga 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.
Kentucky Cooperative Extension
For Kentucky-specific cultivar recommendations, planting calendars, and pest pressure for ajuga, 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 Ajuga native to Kentucky?
No — the USDA PLANTS Database lists Ajuga 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 USDA-documented natives for the state.
Native-range data: USDA PLANTS Database state-distribution records, accessed 2026-07-01.
Common Questions About Growing Ajuga in Kentucky
When can I plant Ajuga 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). No sourced winter-hardiness floor is on record for Ajuga, so this page does not state whether it overwinters in Kentucky 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 Ajuga grown in across Kentucky?
Kentucky spans USDA hardiness zones 6a-7b (USDA ARS PHZM 2023). Ajuga carries a range of zones 5-11, 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). Ajuga 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. In cooler counties like Greenup, the freeze-free season runs shorter than the state average, so verify your own county's window.
Is Ajuga native to Kentucky?
No — the USDA PLANTS Database lists Ajuga 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 Ajuga in Kentucky?
Ajuga prefers pH 5.5-7.5 and well (dry spells) drainage (USDA PLANTS). That sits in the common-ground band across Kentucky soils — a 30-minute soil test from a local Extension lab confirms it for your specific site.
Will Ajuga actually grow on my specific land in Kentucky?
State-level zone + climate data is a sketch. A Growable Ground parcel report scores ajuga 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 Kentucky
State-level data is a sketch. Your Growable Ground report scores ajuga against your parcel's exact soil, sun, drainage, and frost data — not zone averages.
Three things about your lot that Kentucky ajuga 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 ajuga average
Explore More
Growing guides for ajuga
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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