Yes — Strong Match
calibrachoa is grown as an annual, so season length decides it here, not a winter zone — and Texas's typical season runs ~274 frost-free days against the ~60 calibrachoa needs.
Sow by about Oct 2
Calibrachoa is grown as an annual, so what decides it here is season length, not a winter zone. It needs about 60 frost-free days and a typical Texas season runs ~274 frost-free days, leaving 214 days of slack. That is room to sow as late as about Oct 2 and still finish before the usual first freeze (Nov 26), or to run a second succession.
Want more weeks at either end of that window? How to buy the weeks →
60 frost-free days required against Texas’s ~274-day season. NOAA Regional Climate Centers ACIS 1991-2020 (28°F killing freeze), state median across counties, via stateClimateData.ts.
Your yard isn't the whole zone.
Calibrachoa is grown as an annual, so your winter zone isn't the deciding factor — your frost-free window is. A typical Texas site runs ~274 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 calibrachoa against your land's actual frost dates, sun, and soil.
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Zone Comparison
Calibrachoa Needs
- USDA Zones: Data pending
- Frost-Free Days: 60+
- Sun: Full Sun
- Mature size: 6 in tall
- Picking window: ~150 days of harvest
- Drought tolerance: Medium
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
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 Calibrachoa 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.
When to start the seed
Those dates are when calibrachoa goes out, not when it starts. It is sown under cover about 12 weeks ahead, so counting back from Texas's late-side last freeze of Mar 12 is what fixes your sowing date — and a yard that clears frost earlier than the state's late date starts earlier still.
Days to maturity vs. the window
At 55 days to maturity (USDA PLANTS Database), counting from the last hard freeze it ripens with 196 days to spare even in Texas's tightest freeze scenario — room for a later start or a second sowing.
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
Frost-free days
Calibrachoa wants 60+ 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
Calibrachoa needs ~1200 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.
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
Calibrachoa likes near-neutral soil (pH 5-6.5). That's the common-ground band across Texas's black clay (blackland prairie) and sandy 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 Texas soil test result is a problem or just a number. Drainage matters: this plant wants 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 soil pH runs about 7.0–7.9, and that sits above calibrachoa's tolerated 5–6.5, so the typical Texas parcel needs sulfur to bring it down. SSURGO maps it swinging by full points parcel to parcel, so your map unit, not the state number, decides whether calibrachoa needs lime or sulfur.
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.
Calibrachoa in Texas — Quick Answer
- Verdict: Yes — Strong Match
- Plant Zones: Data pending (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)
- Days to Maturity: 55 days
What Else to Consider for Calibrachoa 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 calibrachoa here specifically
Calibrachoa does best acidic (pH 5.0–6.5); Texas soils average near pH 7.5, alkaline enough to yellow its leaves as micronutrients lock away.
Work in elemental sulfur or acidic organic matter to pull your parcel toward pH 5.0–6.5, then retest. How to handle it →
What to actually do about these — and the constraints that apply to every Texas grower, not just calibrachoa — 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 calibrachoa to your county's window, not the statewide date.
Calibrachoa needs about 60 days of frost-free season to complete its cycle. Even Dallam County — Texas’s shortest season at 197 frost-free days — clears that by 137 days, so season length isn’t the constraint anywhere in Texas. What varies is your own parcel.
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 calibrachoa about 214 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"). Calibrachoa'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
Calibrachoa draws honeybees, butterflies, and hummingbirds (moderate value, Growable Ground Plant Database). Planting it near vegetable beds can lift fruit set on neighboring crops. Outdoors, calibrachoa 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.
Recommended Calibrachoa Varieties for Texas
Texas publishes no state variety trial for calibrachoa, so we won't invent a "best for Texas" list. Choose types rated to your USDA hardiness zone (6b-10b), and confirm winter survival and drainage against your own parcel.
Texas Cooperative Extension
For Texas-specific cultivar recommendations, planting calendars, and pest pressure for calibrachoa, 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.
Is Calibrachoa native to Texas?
No — the USDA PLANTS Database lists Calibrachoa as introduced rather than native in the Lower 48, so it is not part of Texas's native flora. It grows here as a garden plant; pairing it with a few Texas natives keeps local pollinators fed too.
Looking for plants that belong here? The Texas 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 Calibrachoa in Texas
When can I plant Calibrachoa 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). Time outdoor planting to after the last hard freeze for your specific site — a further two to three weeks for anything tender — and count back from those dates for transplant scheduling.
Can Calibrachoa mature before first frost in Texas?
Yes — Calibrachoa matures in 55 days (USDA PLANTS Database), and Texas's dependable hard-freeze-free window runs 251 days (NOAA Regional Climate Centers ACIS, 1991-2020), leaving 196 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 Calibrachoa grown in across Texas?
Texas spans USDA hardiness zones 6b-10b (USDA ARS PHZM 2023). Calibrachoa carries a range of zones Data pending, 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). Calibrachoa needs 60+ 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.
Is Calibrachoa native to Texas?
No — the USDA PLANTS Database lists Calibrachoa as introduced rather than native in the Lower 48, so it is not part of Texas's native flora. It grows here as a garden plant; pairing it with a few Texas natives keeps local pollinators fed too.
How should I amend the soil for Calibrachoa in Texas?
Calibrachoa prefers pH 5-6.5 and well (dry spells) drainage (Growable Ground Plant Database). That sits in the common-ground band across Texas soils — a 30-minute soil test from a local Extension lab confirms it for your specific site.
Will Calibrachoa actually grow on my specific land in Texas?
State-level zone + climate data is a sketch. A Growable Ground parcel report scores calibrachoa 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 calibrachoa against your parcel's exact soil, sun, drainage, and frost data — not zone averages.
Three things about your lot that Texas calibrachoa 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 calibrachoa average
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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