Unlikely — Zone Mismatch
red tasselflower (zones 8-11) does not overlap with Kentucky's zone range (6a-7b). Growing outdoors is unlikely without significant protection.
One zone short — what would close it
Red Tasselflower is hardy to zone 8, and the warmest ground in Kentucky is zone 7 — 1 zone short. Planted in open ground it will not survive a Kentucky winter. To grow it here, grow red tasselflower in a hoop house or unheated greenhouse — its modeled 1.5-zone lift covers this gap.
A hoop house or unheated greenhouse is the lift this needs. How a greenhouse changes what you can grow →
Zone math from 8-11 (plant) against 6-7 (Kentucky). Lift modeled by crop_engine.GREENHOUSE_ZONE_MODIFIER_BY_SUBTYPE['hoop_house'] (+1.5 zones) via api/fast_sections.py Unlock Engine v2.
Red Tasselflower in Kentucky — the short answer
Red Tasselflower in Kentucky: hardy in zones 8–11, full sun, against a state median of ~221 frost-free days.
- Plant zones
- 8-11
- 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.
Red Tasselflower 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 red tasselflower 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 red tasselflower 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 Red Tasselflower Stands in Kentucky
Red Tasselflower is rated for zones 8–11 — a cold floor USDA puts at 10 to 20°F. No Kentucky county sits inside it, so in open ground this is a grown-under-cover plant here rather than a bed plant — which is a statement about Kentucky winters, not about red tasselflower.
Below the zone 8 floor
120 counties
- Anderson County · zone 6b
- Bath County · zone 6b
- Boone County · zone 6b
3 of 120 shown
Winter cold is the limit here — the same plant works in a container that comes under cover.
County hardiness zones: USDA Plant Hardiness Zone Map (PHZM) 2023, per county. A zone is a 10°F band of average annual extreme minimum temperature, so the floor above is the band the plant's rating denotes, not a single measured kill point. Slope, shelter and cold-air drainage routinely move a site half a zone either way from its county figure — which is the part only your address resolves.
Zone Comparison
Red Tasselflower Needs
- USDA Zones: 8-11
- Frost-Free Days: 90+
- Sun: Full Sun
- Picking window: ~90 days of harvest
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 8-11)
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 Red Tasselflower 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 red tasselflower 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.
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
The zone check says red tasselflower does not survive a Kentucky winter in the ground. The season figures below measure a different question — whether it could finish a season here at all — and they only bear on Kentucky under protection.
Frost-free days
Red Tasselflower wants 90+ frost-free days; a typical Kentucky site sees ~221 (NOAA Regional Climate Centers ACIS, 1991-2020). That leaves comfortable headroom for succession planting.
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
Red Tasselflower tolerates a wide pH range (pH 4-7) — 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 4.5 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.
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. Red Tasselflower needs about 19 inches of workable depth, so it is that horizon — not the surface — you are testing for. That map unit, not the state average, decides how red tasselflower 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 Red Tasselflower 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 red tasselflower here specifically
Red Tasselflower wants pH 4.0–7.0 and rates to USDA zones 8–11, but Kentucky's soils are dominantly silt loam — the fit is decided by your parcel's own map unit, not the state average.
Match red tasselflower to your parcel's SSURGO map unit — test pH and texture, and amend toward its 4.0–7.0 range. How to handle it →
What to actually do about these — and the constraints that apply to every Kentucky grower, not just red tasselflower — 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 red tasselflower to your county's window, not the statewide date.
Red Tasselflower needs about 90 days of frost-free season to complete its cycle. Even Greenup County — Kentucky’s shortest season at 195 frost-free days — clears that by 105 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"). Red Tasselflower's 90-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
Red Tasselflower draws honeybees and native bees (low value, Growable Ground Plant Database). Planting it near vegetable beds can lift fruit set on neighboring crops. Outdoors, red tasselflower 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.
Recommended Red Tasselflower Varieties for Kentucky
Kentucky publishes no state variety trial for red tasselflower, so we won't invent a "best for Kentucky" list. Choose types rated to your USDA hardiness zone (6a-7b), and confirm winter survival and drainage against your own parcel.
Kentucky Cooperative Extension
For Kentucky-specific cultivar recommendations, planting calendars, and pest pressure for red tasselflower, 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 Red Tasselflower native to Kentucky?
No — the USDA PLANTS Database lists Red Tasselflower 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 Red Tasselflower in Kentucky
When can I plant Red Tasselflower 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.
What hardiness zone is Red Tasselflower grown in across Kentucky?
Kentucky spans USDA hardiness zones 6a-7b (USDA ARS PHZM 2023). Red Tasselflower carries a range of zones 8-11, 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). Red Tasselflower needs 90+ 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 Red Tasselflower native to Kentucky?
No — the USDA PLANTS Database lists Red Tasselflower 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 Red Tasselflower in Kentucky?
Red Tasselflower tolerates pH 4-7 and well (dry spells) drainage (FAO ECOCROP). 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 Red Tasselflower actually grow on my specific land in Kentucky?
State-level zone + climate data is a sketch. A Growable Ground parcel report scores red tasselflower 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 red tasselflower against your parcel's exact soil, sun, drainage, and frost data — not zone averages.
Three things about your lot that Kentucky red tasselflower 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 red tasselflower average
Explore More
Growing guides for red tasselflower
Explore Kentucky county by county
Kentucky carries 120 counties with their own USDA zone — a sample of the growing pages for red tasselflower there:
Where else red tasselflower grows
Red Tasselflower'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 893 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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