Unlikely — Zone Mismatch
coffee senna (zones 12-13) does not overlap with Texas's zone range (6b-10b). Growing outdoors is unlikely without significant protection.
2 zones short — what would close it
Coffee Senna is hardy to zone 12, and the warmest ground in Texas is zone 10 — 2 zones short. Planted in open ground it will not survive a Texas winter. To grow it here, grow coffee senna 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 12-13 (plant) against 6-10 (Texas). 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.
Texas spans zones 6b-10b, 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 coffee senna against your parcel's actual hardiness, soil, and sun.
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Zone Comparison
Coffee Senna Needs
- USDA Zones: 12-13
- Frost-Free Days: 210+
- Sun: Full Sun
- Mature size: 8 ft tall
- Drought tolerance: High
Texas Has
- USDA Zones: 6b-10b
- Last Hard Freeze (28°F): Feb 10 - Mar 12
- First Hard Freeze (28°F): Nov 18 - Dec 4
- Annual Rainfall: 8-56 inches
- Common Soils: Black clay (Blackland Prairie), Sandy loam, Caliche
Plant Zone Range (zones 12-13)
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 Coffee Senna in Texas
The frost window
Across Texas, the last spring hard freeze (28°F) clears between Feb 10 and Mar 12, and the first fall hard freeze lands between Nov 18 and Dec 4 (NOAA Regional Climate Centers ACIS, 1991-2020). Counting from the latest last freeze to the earliest first freeze, that's a 251-day window you can count on — up to 297 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
Texas runs as cold as USDA zone 6, and no sourced winter-hardiness floor is on record for coffee senna, so this page does not state whether it overwinters here — and gives no fall establishment date on the strength of a guess. Whether coffee senna is a permanent planting or a replant-every-spring crop for you turns on your own zone within Texas; check its hardiness range against that before treating it as long-lived ground.
Timing tuned to sub-state frost dates — Dallam 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 coffee senna does not survive a Texas 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 Texas under protection.
Frost-free days
Coffee Senna wants 210+ frost-free days; a typical Texas site sees ~274 (NOAA Regional Climate Centers ACIS, 1991-2020). That leaves comfortable headroom for succession planting.
Growing degree days
Coffee Senna needs ~3000 GDD (base 50°F) to ripen. The state median runs ~5834 GDD (from PRISM 1991-2020 climate normals), so Texas's typical season clears that easily.
Chill hours
Coffee Senna has no winter-chill requirement — its listed minimum is 0 hours (USDA PLANTS Database). Texas typically banks ~1122 chill hours per winter (from PRISM 1991-2020 climate normals), so chill is not a constraint on this plant here — and not evidence in its favour either. Winter survival and season length are what decide it.
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
Coffee Senna tolerates a wide pH range (pH 4.5-8.4) — 3.9 units, acid ground through alkaline — so soil acidity is rarely what limits it in Texas. 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 Texas soil test result is a problem or just a number. Drainage matters: this plant wants poorly (saturated >50% of year), well (dry spells). If your Texas site is heavier clay or sits in a low spot, raised beds or amendment with compost solve it.
Your land, not the state average
Texas's soils run mostly fine sandy loam, but SSURGO maps the series, texture, and drainage under your exact parcel. Coffee Senna 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 coffee senna performs.
Check your parcel → Source: USDA NRCS SSURGO.
Plant pH and drainage requirements from USDA PLANTS Database. Texas soil profile from USDA NRCS SSURGO. Site-specific verification: a 30-minute soil test from your local Extension lab.
Coffee Senna in Texas — Quick Answer
- Verdict: Unlikely — Zone Mismatch
- Plant Zones: 12-13 (USDA PLANTS Database)
- State Zones: 6b-10b (USDA ARS PHZM 2023)
- Growing Season: 28°F hard freezes about Feb 10 - Mar 12 to Nov 18 - Dec 4 (NOAA Regional Climate Centers ACIS, 1991-2020)
What Else to Consider for Coffee Senna in Texas
Zone compatibility tells you about winter cold survival — but Texas growers also need to think about:
Extreme heat (100F+ days) stresses many crops from June through September
Rainfall varies dramatically — 8 inches in west TX to 56 inches in east TX
Heavy black clay (Blackland Prairie) is difficult to work and drains poorly
Flash drought conditions can develop rapidly even in wet years
Growing coffee senna here specifically
Coffee Senna prefers pH 4.5–8.4 and room to root medium; across much of Texas, restrictive group-D subsoil (SSURGO) blocks that depth.
Build coffee senna a deep raised bed of loose soil to bypass the dense subsoil entirely. How to handle it →
What to actually do about these — and the constraints that apply to every Texas grower, not just coffee senna — is covered on the Texas growing guide.
Timing shifts within Texas
Texas isn't one climate. In Dallam County, the last hard freeze (28°F) holds until about Apr 12 — roughly 46 days later than the recorded state median — so plant coffee senna to your county's window, not the statewide date.
Coffee Senna needs about 210 days of frost-free season to complete its cycle. 244 of Texas’s 254 counties give it that outright. The tightest that does is Bailey County at 210 frost-free days — 0 to spare. Below that line you are transplanting or extending the season, not direct-sowing.
Across Texas’s 254 counties the frost-free season runs from 197 days in Dallam County to 343 days in Kenedy County — a spread of 146 days, which is why a single statewide planting date misleads. The median Texas county sees 274 frost-free days, leaving coffee senna about 64 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"). Coffee Senna's 210-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
Coffee Senna draws honeybees and native bees (moderate value, Growable Ground Plant Database). Planting it near vegetable beds can lift fruit set on neighboring crops. Outdoors, coffee senna can only work that bloom inside Texas's frost window — roughly 274 days, opening after the last 28°F freeze (Feb 10 - Mar 12) and closing at the first (Nov 18 - Dec 4), per NOAA Regional Climate Centers ACIS, 1991-2020.
Good to Know Before You Plant Coffee Senna
Coffee Senna 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.
Texas Cooperative Extension
For Texas-specific cultivar recommendations, planting calendars, and pest pressure for coffee senna, the canonical source is Texas A&M AgriLife Extension Service. Their fact sheets carry the local trial data we can't generalize across 50 states.
Common Questions About Growing Coffee Senna in Texas
When can I plant Coffee Senna in Texas?
Texas's last spring hard freeze (28°F) clears between Feb 10 and Mar 12, and the first fall hard freeze lands between Nov 18 and Dec 4 (NOAA Regional Climate Centers ACIS, 1991-2020). No sourced winter-hardiness floor is on record for Coffee Senna, so this page does not state whether it overwinters in Texas 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 Coffee Senna grown in across Texas?
Texas spans USDA hardiness zones 6b-10b (USDA ARS PHZM 2023). Coffee Senna carries a range of zones 12-13, so the overlap zones are where outdoor growing is most reliable.
How many frost-free days does a typical Texas site have?
A typical Texas site sees ~274 frost-free days per year (derived from NOAA Regional Climate Centers ACIS, 1991-2020). Coffee Senna needs 210+ 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 Dallam, the freeze-free season runs shorter than the state average, so verify your own county's window.
How should I amend the soil for Coffee Senna in Texas?
Coffee Senna tolerates pH 4.5-8.4 and poorly (saturated >50% of year), well (dry spells) drainage (FAO ECOCROP). That is a 3.9-unit span, acid ground through alkaline, so pH is rarely what limits this plant on a Texas site — amend for drainage and organic matter first.
Will Coffee Senna actually grow on my specific land in Texas?
State-level zone + climate data is a sketch. A Growable Ground parcel report scores coffee senna 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 Texas
State-level data is a sketch. Your Growable Ground report scores coffee senna against your parcel's exact soil, sun, drainage, and frost data — not zone averages.
Three things about your lot that Texas coffee senna averages can't show:
We read public map data around Texas — soil, climate, flood, and parcel records. How we handle your address.
25+ data sources read at your address, not the Texas coffee senna average
Explore More
Growing guides for coffee senna
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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