tepary bean (Phaseolus acutifolius), photographi

Can I Grow Tepary Bean in Illinois?

USDA Zones 5a-7b · Plant zone range 5-11

Yes — Strong Match

tepary bean (zones 5-11) covers every zone Illinois contains (5a-7b), so hardiness is not what limits it anywhere in the state.

Tepary Bean in Illinois — the short answer

Tepary Bean in Illinois: hardy in zones 5–11, full sun, against a state median of ~212 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
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
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.

Score your parcel · free

Your yard isn't the whole zone.

Tepary Bean is grown as an annual, so your winter zone isn't the deciding factor — your frost-free window is. A typical Illinois site runs ~212 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 tepary bean 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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Illinois is not one climate

A single Illinois answer averages 102 counties whose growing seasons are 67 days apart — from 177 frost-free days in Jo Daviess County to 244 in Alexander County. Which end of that your land sits nearer changes what tepary bean can finish before the first hard freeze.

177 daysJo Daviess County244 daysAlexander County

The middle half of 102 counties runs 203221 days, with a median of 212 days — a 67-day span end to end.

Measured across 102 Illinois 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 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 tepary bean (USDA PHZM 2023):

Zone Comparison

Tepary Bean Needs

  • USDA Zones: 5-11
  • Frost-Free Days: 60+
  • Sun: Full Sun
  • Mature size: 1.5 ft tall
  • Picking window: ~21 days of harvest
  • Drought tolerance: High

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 5-11)

5a
11b
3a (Cold)13b (Hot)

Preferred Soil pH

3.5 (Acidic)7.0 (Neutral)9.0 (Alkaline)
Highlighted range: pH 5.08.0

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 Tepary Bean 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.

Frost hardiness

Tepary Bean takes cold down to about 28°F before a freeze kills it (FAO ECOCROP), so you can plant on the early side of Illinois'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

Tepary Bean is direct-sown where it grows rather than started under cover, so there is no seed-tray head start to bank — Illinois'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 113 days to spare even in Illinois'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 tepary bean survives winter here. Whether the season is long enough — and warm enough — is a different question.

Frost-free days

Tepary Bean wants 60+ frost-free days; a typical Illinois site sees ~212 (NOAA Regional Climate Centers ACIS, 1991-2020). That leaves comfortable headroom for succession planting.

Growing degree days

Tepary Bean needs ~1800 GDD (base 50°F) to ripen. The state median runs ~3352 GDD (from PRISM 1991-2020 climate normals), so Illinois'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

Tepary Bean tolerates a wide pH range (pH 5-8) — 3 units, acid ground through alkaline — so soil acidity is rarely what limits it in Illinois. 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 7 — worth knowing before you decide whether a Illinois soil test result is a problem or just a number. Drainage matters: this plant wants well (dry spells). If your Illinois 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. Illinois soil profile from USDA NRCS SSURGO. Site-specific verification: a 30-minute soil test from your local Extension lab.

Before you plant tepary bean 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 tepary bean goes in. What follows is Illinois’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 Illinois — and how to grow with it.

Federal record: High

We checked the federal record across Illinois52,971 documented sites across 8 of the 9 source types we track.

The most significant on record: 622 Superfund sites. Sites tracked in EPA's Superfund program — from assessment-stage CERCLIS entries to confirmed National Priorities List cleanup sites.

Illinois 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 with clean imported soil grow well almost anywhere in the meantime.

Severity Distribution

across Illinois

High513Moderate12,353Low40,105

Highest-Severity Sites

A & F Material Reclaiming, INC.
Superfund · Superfund NPL
Abingdon
PFAS Sampling · PFAS Detected
Acme Steel CO
Superfund · Superfund NPL
Adams County Quincy Landfills 2&3
Superfund · Superfund NPL

A note from Gnorman

What an experienced grower watches for around here

In and around Illinois, two things run higher than the national average across Illinois — PFAS (482 sites) and Toxics Release Inventory (3,504 sites). That's not a problem with your land — it's information about it.

PFAS: PFAS (per- and polyfluoroalkyl substances) are called "forever chemicals" because they do not biodegrade.

Toxics Release Inventory: TRI facilities report annual chemical releases to air, water, and land.

Test irrigation water source — this is the primary pathway for PFAS to reach garden crops.

Check prevailing wind direction — downwind parcels face higher exposure than upwind or crosswind locations.

Sources: EPA, USGS1.8M documented sites tracked nationwide across 9 federal source types.

What Else to Consider for Tepary Bean 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

What to actually do about these — and the constraints that apply to every Illinois grower, not just tepary bean — is covered on the Illinois growing guide.

Timing shifts within Illinois

Tepary Bean needs about 60 days of frost-free season to complete its cycle. Even Jo Daviess County — Illinois’s shortest season at 177 frost-free days — clears that by 117 days, so season length isn’t the constraint anywhere in Illinois. What varies is your own parcel.

Across Illinois’s 102 counties the frost-free season runs from 177 days in Jo Daviess County to 244 days in Alexander County — a spread of 67 days, which is why a single statewide planting date misleads. The median Illinois county sees 212 frost-free days, leaving tepary bean about 152 days of slack on a typical parcel — room for a second sowing where the season runs long.

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"). Tepary Bean's 60-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

Tepary Bean draws honeybees and native bees (moderate value, Growable Ground Plant Database). Planting it near vegetable beds can lift fruit set on neighboring crops. Outdoors, tepary bean can only work that bloom inside Illinois's frost window — roughly 212 days, opening after the last 28°F freeze (Mar 29 - Apr 8) and closing at the first (Oct 28 - Nov 5), per NOAA Regional Climate Centers ACIS, 1991-2020.

Illinois Cooperative Extension

For Illinois-specific cultivar recommendations, planting calendars, and pest pressure for tepary bean, the canonical source is University of Illinois Extension. Their fact sheets carry the local trial data we can't generalize across 50 states.

Is Tepary Bean native to Illinois?

Tepary Bean is native to parts of the Lower 48, but the USDA PLANTS Database (accessed 2026-07-01) does not document a native range in Illinois. It can still earn a place in a Illinois garden — the zone comparison above tells you whether it will thrive.

Looking for plants that belong here? The Illinois 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 Tepary Bean in Illinois

When can I plant Tepary Bean 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). Tepary Bean takes cold to about 28°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 Tepary Bean mature before first frost in Illinois?

Yes — Tepary Bean matures in 90 days (Growable Ground Plant Database), and Illinois's dependable hard-freeze-free window runs 203 days (NOAA Regional Climate Centers ACIS, 1991-2020), leaving 113 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 Tepary Bean grown in across Illinois?

Illinois spans USDA hardiness zones 5a-7b (USDA ARS PHZM 2023). Tepary Bean 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 Illinois site have?

A typical Illinois site sees ~212 frost-free days per year (derived from NOAA Regional Climate Centers ACIS, 1991-2020). Tepary Bean needs 60+ frost-free days, so check whether your local microclimate runs above or below the state average before settling on a planting date.

Is Tepary Bean native to Illinois?

Tepary Bean is native to parts of the Lower 48, but the USDA PLANTS Database (accessed 2026-07-01) does not document a native range in Illinois. It can still earn a place in a Illinois garden — the zone comparison above tells you whether it will thrive.

How should I amend the soil for Tepary Bean in Illinois?

Tepary Bean tolerates pH 5-8 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 Illinois site — amend for drainage and organic matter first.

Will Tepary Bean actually grow on my specific land in Illinois?

State-level zone + climate data is a sketch. A Growable Ground parcel report scores tepary bean against your address's exact soil pH, drainage, sun, and frost-date data drawn from USDA SSURGO, NOAA, and PRISM — not state averages.

Free Report

Check your specific parcel in Illinois

State-level data is a sketch. Your Growable Ground report scores tepary bean against your parcel's exact soil, sun, drainage, and frost data — not zone averages.

Three things about your lot that Illinois tepary bean averages can't show:

Your soil pHYour frost-free days — Illinois averages 212Your sun & shade

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 tepary bean average

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