Unlikely — Zone Mismatch
cardamom (zones 10-13) does not overlap with Tennessee's zone range (6a-8a). Growing outdoors is unlikely without significant protection.
2 zones short — what would close it
Cardamom is hardy to zone 10, and the warmest ground in Tennessee is zone 8 — 2 zones short. Planted in open ground it will not survive a Tennessee winter. To grow it here, grow cardamom under glass — a greenhouse is the only lift this wide the engine models.
A greenhouse is the lift this needs. How a greenhouse changes what you can grow →
Zone math from 10-13 (plant) against 6-8 (Tennessee). Lift modeled by crop_engine Sprint 20B effective_zone_modifier (+2 zones) via api/fast_sections.py Unlock Engine v2.
Your yard isn't the whole zone.
Tennessee spans zones 6a-8a, but your yard has its own microclimate — slope, trees, and low spots shift frost and sun across a single parcel. Enter your address and we'll score cardamom against your land's actual soil, sun, and frost.
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Zone Comparison
Cardamom Needs
- USDA Zones: 10-13
- Frost-Free Days: 240+
- Sun: Part Sun
- Mature size: 12 ft tall
- Drought tolerance: Low
Tennessee Has
- USDA Zones: 6a-8a
- Last Hard Freeze (28°F): Mar 21 - Mar 29
- First Hard Freeze (28°F): Nov 5 - Nov 12
- Annual Rainfall: 45-55 inches
- Common Soils: Silt loam, Clay loam, Limestone-derived
Plant Zone Range (zones 10-13)
Preferred Soil pH
Plant data: USDA PLANTS Database / Growable Ground plant catalog. State data: USDA ARS PHZM 2023, NOAA Climate Normals, NRCS SSURGO.
When to Plant Cardamom in Tennessee
The frost window
Across Tennessee, the last spring hard freeze (28°F) clears between Mar 21 and Mar 29, and the first fall hard freeze lands between Nov 5 and Nov 12 (NOAA Regional Climate Centers ACIS, 1991-2020). Counting from the latest last freeze to the earliest first freeze, that's a 221-day window you can count on — up to 236 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 tenderness
Cardamom is frost-tender — its listed minimum temperature is 50°F (USDA PLANTS Database) — so set plants out two to three weeks PAST your local last hard freeze, not on it and not on the state's earliest date. The 28°F marker above is when killing freezes stop, not when light frost does.
When to start the seed
Those dates are when cardamom goes out, not when it starts. It is sown under cover about 12 weeks ahead, so counting back from Tennessee's late-side last freeze of Mar 29 is what fixes your sowing date — and a yard that clears frost earlier than the state's late date starts earlier still.
Grown as an annual here
Cardamom is a true perennial in its home range — it overwinters from USDA zone 10 and warmer (NC State Extension Gardener Plant Toolbox; Missouri Botanical Garden Plant Finder) — but Tennessee runs as cold as zone 6, so it is killed back each winter and replanted each spring. Treat it on the season schedule above, not as a permanent planting: there is no fall establishment window for it here.
Timing tuned to sub-state frost dates — Johnson County, not the statewide average.
Frost window: NOAA Climate Normals 1991-2020. Plant timing fields: USDA PLANTS Database. 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 cardamom does not survive a Tennessee 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 Tennessee under protection.
Frost-free days
Cardamom wants 240+ frost-free days; a typical Tennessee site sees ~230 (NOAA Regional Climate Centers ACIS, 1991-2020) — 10 days short of what it needs. A typical Tennessee season does not carry this crop to harvest outdoors, and a gap that size is not one an earlier sowing date or a faster cultivar closes; growing it here means growing it under cover.
Growing degree days
Cardamom needs ~5000 GDD (base 50°F) to ripen. The state median runs ~4122 GDD (from PRISM 1991-2020 climate normals), so Tennessee's typical season runs short on heat — pick a south-facing site and consider season extension.
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
Cardamom likes near-neutral soil (pH 4.8-7). That's the common-ground band across Tennessee's silt loam and clay loam — a soil test confirms it for your site. It will grow across that whole span, but it does best between pH 5.5 and 6 — worth knowing before you decide whether a Tennessee soil test result is a problem or just a number. Drainage matters: this plant wants well (dry spells). If your Tennessee site is heavier clay or sits in a low spot, raised beds or amendment with compost solve it.
Your land, not the state average
Tennessee's soils run mostly silt loam, but SSURGO maps the series, texture, and drainage under your exact parcel. Cardamom needs about 7 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 cardamom performs.
Check your parcel → Source: USDA NRCS SSURGO.
Plant pH and drainage requirements from USDA PLANTS Database. Tennessee soil profile from USDA NRCS SSURGO. Site-specific verification: a 30-minute soil test from your local Extension lab.
Cardamom in Tennessee — Quick Answer
- Verdict: Unlikely — Zone Mismatch
- Plant Zones: 10-13 (USDA PLANTS Database)
- State Zones: 6a-8a (USDA ARS PHZM 2023)
- Growing Season: 28°F hard freezes about Mar 21 - Mar 29 to Nov 5 - Nov 12 (NOAA Regional Climate Centers ACIS, 1991-2020)
- Days to Maturity: 365 days
What Else to Consider for Cardamom in Tennessee
Zone compatibility tells you about winter cold survival — but Tennessee growers also need to think about:
Heavy clay soils in the Nashville Basin
High humidity promotes disease in summer
Variable spring weather with late frost risk
Growing cardamom here specifically
Cardamom needs about 365 days to mature, but a typical Tennessee site has only ~230 frost-free days (NOAA) — a late start can leave it racing the first freeze.
Start cardamom indoors early or use a low tunnel to stretch the season on the cold end. How to handle it →
What to actually do about these — and the constraints that apply to every Tennessee grower, not just cardamom — is covered on the Tennessee growing guide.
Timing shifts within Tennessee
Tennessee isn't one climate. In Johnson County, the last hard freeze (28°F) holds until about Apr 14 — roughly 21 days later than the recorded state median — so plant cardamom to your county's window, not the statewide date.
Cardamom needs about 240 days of frost-free season to complete its cycle. 13 of Tennessee’s 95 counties give it that outright. The tightest that does is Hardeman County at 240 frost-free days — 0 to spare. Below that line you are transplanting or extending the season, not direct-sowing.
Across Tennessee’s 95 counties the frost-free season runs from 193 days in Johnson County to 266 days in Shelby County — a spread of 73 days, which is why a single statewide planting date misleads. The median Tennessee county sees 230 frost-free days, which is 10 days short of what cardamom needs — so on a typical Tennessee parcel this is a transplant-or-protect crop, not a direct-sow one.
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"). Cardamom's 240-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
Cardamom draws native bees (low value, Growable Ground Plant Database). Planting it near vegetable beds can lift fruit set on neighboring crops. Outdoors, cardamom can only work that bloom inside Tennessee's frost window — roughly 230 days, opening after the last 28°F freeze (Mar 21 - Mar 29) and closing at the first (Nov 5 - Nov 12), per NOAA Regional Climate Centers ACIS, 1991-2020.
Recommended Cardamom Varieties for Tennessee
Tennessee publishes no state variety trial for cardamom, so we won't invent a "best for Tennessee" list. Choose types rated to your USDA hardiness zone (6a-8a), and confirm winter survival and drainage against your own parcel.
Tennessee Cooperative Extension
For Tennessee-specific cultivar recommendations, planting calendars, and pest pressure for cardamom, the canonical source is UT Extension. Their fact sheets carry the local trial data we can't generalize across 50 states.
Common Questions About Growing Cardamom in Tennessee
When can I plant Cardamom in Tennessee?
Tennessee's last spring hard freeze (28°F) clears between Mar 21 and Mar 29, and the first fall hard freeze lands between Nov 5 and Nov 12 (NOAA Regional Climate Centers ACIS, 1991-2020). Cardamom overwinters only from USDA zone 10 and warmer, and Tennessee runs as cold as zone 6, so it is grown as an annual here — plant it after the last hard freeze, two to three weeks later for tender stock, and expect to replant next spring rather than establishing it for the long term.
What hardiness zone is Cardamom grown in across Tennessee?
Tennessee spans USDA hardiness zones 6a-8a (USDA ARS PHZM 2023). Cardamom carries a range of zones 10-13, so the overlap zones are where outdoor growing is most reliable.
How many frost-free days does a typical Tennessee site have?
A typical Tennessee site sees ~230 frost-free days per year (derived from NOAA Regional Climate Centers ACIS, 1991-2020). Cardamom needs 240+ 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 Johnson, the freeze-free season runs shorter than the state average, so verify your own county's window.
How should I amend the soil for Cardamom in Tennessee?
Cardamom prefers pH 4.8-7 and well (dry spells) drainage (FAO ECOCROP). That sits in the common-ground band across Tennessee soils — a 30-minute soil test from a local Extension lab confirms it for your specific site.
Will Cardamom actually grow on my specific land in Tennessee?
State-level zone + climate data is a sketch. A Growable Ground parcel report scores cardamom 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 Tennessee
State-level data is a sketch. Your Growable Ground report scores cardamom against your parcel's exact soil, sun, drainage, and frost data — not zone averages.
Three things about your lot that Tennessee cardamom averages can't show:
We read public map data around Tennessee — soil, climate, flood, and parcel records. How we handle your address.
25+ data sources read at your address, not the Tennessee cardamom average
Explore More
Growing guides for cardamom
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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