coffee senna (Cassia occidentalis), photographi

Can I Grow Coffee Senna in Texas?

USDA Zones 6b-10b · Plant zone range 12-13

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 in an earth-sheltered greenhouse — its modeled 2.5-zone lift covers this gap.

An earth-sheltered 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.GREENHOUSE_ZONE_MODIFIER_BY_SUBTYPE['earth_sheltered'] (+2.5 zones) via api/fast_sections.py Unlock Engine v2.

Coffee Senna in Texas — the short answer

Coffee Senna in Texas: hardy in zones 12–13, full sun, against a state median of ~274 frost-free days.

Plant zones
12-13
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
Texas zones
6b-10b
USDA PHZM 2023
Frost window
Feb 10 - Mar 12 – Nov 18 - Dec 4
NOAA RCC ACIS 1991-2020, 28°F
Shortest county season
197 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.

Score your parcel · free

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.

We read public map data for this spot — soil, climate, flood, and parcel records. How we handle your address.

No card required · your full report in seconds

Texas is not one climate

Texas’s winter-low ladder runs across 254 counties, from zone 6.5 in Dallam County to zone 10 in Willacy County. That is 35°F between the two counties’ average coldest night — the difference between coffee senna overwintering in the ground and coming under cover.

6.5 zonesDallam County10 zonesWillacy County

The middle half of 254 counties runs 89 zones, with a median of 8.5 zones — a 3.5-zone span end to end.

Measured across 254 Texas 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 Coffee Senna Stands in Texas

Coffee Senna is rated for zones 1213 — a cold floor USDA puts at 50 to 60°F. No Texas 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 Texas winters, not about coffee senna.

Below the zone 12 floor

254 counties

3 of 254 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

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)

12a
13b
3a (Cold)13b (Hot)

Preferred Soil pH

3.5 (Acidic)7.0 (Neutral)9.0 (Alkaline)
Highlighted range: pH 4.58.4

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 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: 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 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 (Growable Ground Plant 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 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. Texas soil profile from USDA NRCS SSURGO. Site-specific verification: a 30-minute soil test from your local Extension lab.

Before you plant coffee senna 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 coffee senna goes in. What follows is Texas’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 Texas — and how to grow with it.

Federal record: High

We checked the federal record across Texas93,167 documented sites across 8 of the 9 source types we track.

The most significant on record: 480 Superfund sites. Sites tracked in EPA's Superfund program — from assessment-stage CERCLIS entries to confirmed National Priorities List cleanup sites.

Texas 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.

Know before you grow — the guide

Sources Checked

across Texas

Severity Distribution

across Texas

High1,175Moderate35,505Low56,487

Highest-Severity Sites

PFAS Sampling · PFAS Detected
PFAS Sampling · PFAS Detected
PFAS Sampling · PFAS Detected
PFAS Sampling · PFAS Detected
PFAS Sampling · PFAS Detected

A note from Gnorman

What an experienced grower watches for around here

In and around Texas, two things run higher than the national average across Texas — PFAS (1,103 sites) and Underground Storage Tanks (61,246 sites). It's not cause for alarm — it's worth knowing, and there's a sensible way to grow around it.

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

Underground Storage Tanks: Underground storage tanks are the single most common source of soil contamination near homes and gardens.

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

Use raised beds with imported soil — this eliminates the primary soil-contact pathway.

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

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.

Free Report

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:

Your soil pHYour frost-free days — Texas averages 274Your sun & shade

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

Explore Texas county by county

Texas carries 254 counties with their own USDA zone — a sample of the growing pages for coffee senna there:

Where else coffee senna grows

Coffee Senna's zone band crosses state lines — these are the states closest to Texas 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 Texas

Texas has a growing page for 1,041 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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