Yes — Strong Match
subterranean clover (zones 6-10) covers every zone Kentucky contains (6a-7b), so hardiness is not what limits it anywhere in the state.
Subterranean Clover in Kentucky — the short answer
Subterranean Clover in Kentucky: hardy in zones 6–10, full sun, against a state median of ~221 frost-free days.
- Plant zones
- 6-10
- 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
- Days to maturity
- 90 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.
Subterranean Clover 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 subterranean clover against your land's actual frost dates, sun, and soil.
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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 subterranean clover 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 subterranean clover (USDA PHZM 2023):
Zone Comparison
Subterranean Clover Needs
- USDA Zones: 6-10
- Frost-Free Days: 120+
- Sun: Full 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 6-10)
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 Subterranean Clover 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.
Frost hardiness
Subterranean Clover takes cold down to about 10°F before a freeze kills it (FAO ECOCROP), so you can plant on the early side of Kentucky's window — even a few weeks before the final hard freeze. That is the point where cold damages growing tissue, not a winter-survival floor — an established perennial comes through far colder while dormant, which is what its hardiness zone tells you.
When to start the seed
Subterranean Clover is direct-sown where it grows rather than started under cover, so there is no seed-tray head start to bank — Kentucky's dates above are the whole calendar for it. That makes the last-freeze date the binding constraint, and a warmer pocket of your own yard is worth more to this crop than it is to a transplanted one.
Days to maturity vs. the window
At 90 days to maturity (Growable Ground Plant Database), counting from the last hard freeze it ripens with 126 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
The zone check says subterranean clover survives winter here. Whether the season is long enough — and warm enough — is a different question.
Frost-free days
Subterranean Clover 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
Subterranean Clover needs ~800 GDD (base 50°F) to ripen. 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
Subterranean Clover tolerates a wide pH range (pH 5-8) — 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 5.5 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, raised beds or amendment with compost solve it.
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 Subterranean Clover 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
What to actually do about these — and the constraints that apply to every Kentucky grower, not just subterranean clover — is covered on the Kentucky growing guide.
Timing shifts within Kentucky
Subterranean Clover 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"). Subterranean Clover'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
Subterranean Clover draws honeybees, native bees, and butterflies (high value, Growable Ground Plant Database). Planting it near vegetable beds can lift fruit set on neighboring crops. Outdoors, subterranean clover 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 subterranean clover, 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 Subterranean Clover native to Kentucky?
No — the USDA PLANTS Database lists Subterranean Clover 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 Subterranean Clover in Kentucky
When can I plant Subterranean Clover 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). Subterranean Clover takes cold to about 10°F before a freeze kills it (FAO ECOCROP — the point where cold damages growing tissue, not a winter-survival floor), so plant on the early side of that window — even ahead of the final hard freeze.
Can Subterranean Clover mature before first frost in Kentucky?
Yes — Subterranean Clover matures in 90 days (Growable Ground Plant Database), and Kentucky's dependable hard-freeze-free window runs 216 days (NOAA Regional Climate Centers ACIS, 1991-2020), leaving 126 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 Subterranean Clover grown in across Kentucky?
Kentucky spans USDA hardiness zones 6a-7b (USDA ARS PHZM 2023). Subterranean Clover carries a range of zones 6-10, 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). Subterranean Clover 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 Subterranean Clover native to Kentucky?
No — the USDA PLANTS Database lists Subterranean Clover 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 Subterranean Clover in Kentucky?
Subterranean Clover tolerates pH 5-8 and well (dry spells) drainage (Growable Ground Plant Database). 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 Subterranean Clover actually grow on my specific land in Kentucky?
State-level zone + climate data is a sketch. A Growable Ground parcel report scores subterranean clover 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 subterranean clover against your parcel's exact soil, sun, drainage, and frost data — not zone averages.
Three things about your lot that Kentucky subterranean clover averages can't show:
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