Yes — Strong Match
Kentucky coffeetree (zones 4-10) covers every zone Illinois contains (5a-7b), so hardiness is not what limits it anywhere in the state.
Kentucky Coffeetree in Illinois — the short answer
Kentucky Coffeetree in Illinois: hardy in zones 4–10, full sun, against a state median of ~212 frost-free days.
- Plant zones
- 4-10
- 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
- Illinois zones
- 5a-7b
- USDA PHZM 2023
- Frost window
- Mar 29 - Apr 8 – Oct 28 - Nov 5
- NOAA RCC ACIS 1991-2020, 28°F
- Shortest county season
- 177 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.
Illinois spans zones 5a-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 kentucky coffeetree 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.
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Illinois is not one climate
Illinois’s winter-low ladder runs across 102 counties, from zone 5 in Carroll County to zone 7 in Williamson County. That is 20°F between the two counties’ average coldest night — the difference between kentucky coffeetree overwintering in the ground and coming under cover.
The middle half of 102 counties runs 5.5–6.5 zones, with a median of 6 zones — a 2-zone span end to end.
Measured across 102 Illinois 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 Illinois Fits Best
Even within Illinois's zones 5a-7b, county microclimates differ enough to change what thrives. These counties carry the closest zone match for kentucky coffeetree (USDA PHZM 2023):
Zone Comparison
Kentucky Coffeetree Needs
- USDA Zones: 4-10
- Sun: Full Sun
- Mature size: 75 ft tall
- Drought tolerance: Medium
Illinois Has
- USDA Zones: 5a-7b
- Last Hard Freeze (28°F): Mar 29 - Apr 8
- First Hard Freeze (28°F): Oct 28 - Nov 5
- Annual Rainfall: 34-48 inches
- Common Soils: Prairie loam, Silt loam, Clay loam
Plant Zone Range (zones 4-10)
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 Kentucky Coffeetree in Illinois
The frost window
Across Illinois, the last spring hard freeze (28°F) clears between Mar 29 and Apr 8, and the first fall hard freeze lands between Oct 28 and Nov 5 (NOAA Regional Climate Centers ACIS, 1991-2020). Counting from the latest last freeze to the earliest first freeze, that's a 203-day window you can count on — up to 221 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
Illinois runs as cold as USDA zone 5, and no sourced winter-hardiness floor is on record for kentucky coffeetree, so this page does not state whether it overwinters here — and gives no fall establishment date on the strength of a guess. Whether kentucky coffeetree is a permanent planting or a replant-every-spring crop for you turns on your own zone within Illinois; check its hardiness range against that before treating it as long-lived ground.
Timing tuned to sub-state frost dates — Jo Daviess 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 kentucky coffeetree survives winter here. Whether the season is long enough — and warm enough — is a different question.
Chill hours
Kentucky Coffeetree requires ~500 chill hours (32-45°F dormancy window). Illinois typically banks ~2500 chill hours per winter (from PRISM 1991-2020 climate normals), which keeps this plant on track.
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
Kentucky Coffeetree likes near-neutral soil (pH 6-8). That's the common-ground band across Illinois's prairie loam and silt loam — a soil test confirms it for your site.
Your land, not the state average
Illinois's soils run mostly silt loam, but SSURGO maps the series, texture, and drainage under your exact parcel. What matters for kentucky coffeetree is the horizon its roots actually work, not the surface. That map unit, not the state average, decides how kentucky coffeetree 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. Illinois soil profile from USDA NRCS SSURGO. Site-specific verification: a 30-minute soil test from your local Extension lab.
What Else to Consider for Kentucky Coffeetree in Illinois
Zone compatibility tells you about winter cold survival — but Illinois growers also need to think about:
Heavy clay soils in northern IL drain poorly
Extreme temperature swings between summer and winter
Japanese beetles are a major garden pest
Growing kentucky coffeetree here specifically
Kentucky Coffeetree wants pH 6.0–8.0 and rates to USDA zones 4–10, but Illinois's soils are dominantly silt loam — the fit is decided by your parcel's own map unit, not the state average.
Match kentucky coffeetree to your parcel's SSURGO map unit — test pH and texture, and amend toward its 6.0–8.0 range. How to handle it →
What to actually do about these — and the constraints that apply to every Illinois grower, not just kentucky coffeetree — is covered on the Illinois growing guide.
Timing shifts within Illinois
Illinois isn't one climate. In Jo Daviess County, the last hard freeze (28°F) holds until about Apr 22 — roughly 20 days later than the recorded state median — so plant kentucky coffeetree 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 Illinois Kentucky Coffeetree Is Zone-Hardy
Kentucky Coffeetree is rated for USDA zones 4–10. Every one of Illinois’s 102 counties sits inside that band — from Carroll County at zone 5a to Williamson County at zone 7a — 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 102 counties Illinois’s winter-low ladder runs from zone 5a in Carroll County to zone 7a in Williamson County — 2 USDA zones of spread, which is 20°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. Jo Daviess County holds its last hard freeze (28°F) until about Apr 22, while Alexander County is clear by Mar 17 — 36 days apart. Set kentucky coffeetree 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". Kentucky Coffeetree’s zone 4–10 band: USDA PLANTS / Growable Ground plant database. A parcel report resolves your address’s own zone and frost dates rather than its county’s.
Good to Know Before You Plant Kentucky Coffeetree
Kentucky Coffeetree is listed as toxic to dogs, cats (seeds) at a moderate level (Cornell). Most listed plants only cause brief upset — a raised bed or a fenced corner usually keeps curious pets clear.
Illinois Cooperative Extension
For Illinois-specific cultivar recommendations, planting calendars, and pest pressure for kentucky coffeetree, the canonical source is University of Illinois Extension. Their fact sheets carry the local trial data we can't generalize across 50 states.
Is Kentucky Coffeetree native to Illinois?
Yes — the USDA PLANTS Database (accessed 2026-07-01) documents Kentucky Coffeetree as native to Illinois. Planting it supports the pollinators and wildlife that evolved alongside it.
Native-range data: USDA PLANTS Database state-distribution records, accessed 2026-07-01.
Common Questions About Growing Kentucky Coffeetree in Illinois
When can I plant Kentucky Coffeetree in Illinois?
Illinois's last spring hard freeze (28°F) clears between Mar 29 and Apr 8, and the first fall hard freeze lands between Oct 28 and Nov 5 (NOAA Regional Climate Centers ACIS, 1991-2020). No sourced winter-hardiness floor is on record for Kentucky Coffeetree, so this page does not state whether it overwinters in Illinois 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 Kentucky Coffeetree grown in across Illinois?
Illinois spans USDA hardiness zones 5a-7b (USDA ARS PHZM 2023). Kentucky Coffeetree carries a range of zones 4-10, so the overlap zones are where outdoor growing is most reliable.
How many frost-free days does a typical Illinois site have?
A typical Illinois site sees ~212 frost-free days per year (derived from NOAA Regional Climate Centers ACIS, 1991-2020). Kentucky Coffeetree 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 Jo Daviess, the freeze-free season runs shorter than the state average, so verify your own county's window.
Is Kentucky Coffeetree native to Illinois?
Yes — the USDA PLANTS Database (accessed 2026-07-01) documents Kentucky Coffeetree as native to Illinois. Planting it supports the pollinators and wildlife that evolved alongside it.
How should I amend the soil for Kentucky Coffeetree in Illinois?
Kentucky Coffeetree prefers pH 6-8 (USDA PLANTS). That sits in the common-ground band across Illinois soils — a 30-minute soil test from a local Extension lab confirms it for your specific site.
Will Kentucky Coffeetree actually grow on my specific land in Illinois?
State-level zone + climate data is a sketch. A Growable Ground parcel report scores kentucky coffeetree 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 Illinois
State-level data is a sketch. Your Growable Ground report scores kentucky coffeetree against your parcel's exact soil, sun, drainage, and frost data — not zone averages.
Three things about your lot that Illinois kentucky coffeetree averages can't show:
We read public map data around Illinois — soil, climate, flood, and parcel records. How we handle your address.
25+ data sources read at your address, not the Illinois kentucky coffeetree average
Explore More
Growing guides for kentucky coffeetree
Explore Illinois county by county
Illinois carries 102 counties with their own USDA zone — a sample of the growing pages for kentucky coffeetree there:
Where else kentucky coffeetree grows
Kentucky Coffeetree's zone band crosses state lines — these are the states closest to Illinois 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 Illinois
Illinois 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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