US Grow Zones

Carrollton, Texas: planting zone & frost dates

Last updated · Sources: PRISM/OSU 2023 ZIP zone listings; NOAA NCEI 1991–2020 Climate Normals (station USW00003927); U.S. Census Bureau — see methodology

Carrollton is in USDA plant hardiness zone 8b, where the average coldest winter night reaches 15 to 20°F (-9.4 to -6.7°C). The typical last spring frost is around Mar 15 and the first fall frost around Nov 15.

Hardiness zone8B15 to 20°F
Last spring frostMar 1530% chance of frost after
First fall frostNov 1530% chance of frost before
Growing season262 daysmedian frost-free days

Frost dates

ProbabilityLast spring frost (32°F)First fall frost (32°F)
Safer (10% risk)Mar 26Nov 6
Typical planning date (30% risk)Mar 15Nov 15
Median (50%)Mar 8Nov 24

How to read this: after the spring "10% risk" date, a 32°F frost happens in only about 1 year in 10. In fall, the "10% risk" date is the early end — a frost before it happens about 1 year in 10.

Frost data comes from NOAA station DALLAS FT WORTH AP, TX (USW00003927), 9.4 mi (15.1 km) from the city center and 79 ft higher than the city center (+24 m). Record used for the 1991–2020 normals: 26 years.

Frost probability in spring and fall, Carrollton, TXChance of a 32°F frost in Carrollton, TX, NOAA 1991–2020. Spring: the chance of another frost falls from 90% on Feb 17 to 10% on Mar 26. Fall: the chance that the first frost has arrived rises from 10% on Nov 6 to 90% on Dec 12.0%50%100%Spring: later frostFeb 1Mar 1Apr 130%: Mar 15Fall: frost arrivedNov 1Dec 1Jan 130%: Nov 1532°F frost28°F hard freezeplanning date
Shaded areas show the chance of a 32°F frost: falling through spring, rising through fall. The dashed line is the 28°F hard-freeze curve. Data: NOAA 1991–2020 Normals, station USW00003927.
Frost-free growing season in Carrollton, TX1 in 10 risk: Mar 26 to Nov 6 (225 days); 3 in 10 risk: Mar 15 to Nov 15 (245 days); Median (50%): Mar 8 to Nov 24 (261 days); No 28°F freeze: Feb 25 to Dec 7 (285 days). In 9 of 10 years the 32°F-free season is at least 236 days.Frost-free days, spring to fallJFMAMJJASOND1 in 10 risk225 days3 in 10 risk245 daysMedian (50%)261 daysNo 28°F freeze285 days
Frost-free window at three risk levels, plus the window between 28°F hard freezes. Read about what the probabilities mean.

Why your yard may differ from the station: microclimates.

Hardiness zone across Carrollton

All 4 ZIP codes covering Carrollton are in zone 8b.

ZIP codes in Carrollton and their zones
ZIPZoneShare of city land
750068b45.6%
750078b32.0%
750108b17.7%
750198b2.8%

Vegetable planting calendar for Carrollton

Dates are counted from the 30%-risk frost dates above (last frost Mar 15, first frost Nov 15). Shift a week later in cold spots or low-lying ground.

CropStart indoorsTransplant / plant outDirect sowFall crop sow/plant
TomatoJan 18 – Feb 1Mar 22 – Apr 5——
PepperJan 4 – Jan 18Mar 29 – Apr 12——
LettuceFeb 1 – Feb 15Mar 1 – Mar 22Feb 15 – Mar 29Sep 6 – Oct 4
Green Beans——Mar 22 – Apr 26Aug 23 – Sep 6
Sweet Corn——Mar 22 – Apr 19—
Zucchini & Summer SquashFeb 15 – Feb 22Mar 22 – Apr 5Mar 22 – Apr 12Aug 23 – Sep 6
CucumberFeb 15 – Feb 22Mar 29 – Apr 5Mar 22 – Apr 12Aug 23 – Sep 6
Carrot——Feb 22 – Mar 29Aug 23 – Sep 6
OnionDec 21 – Jan 4Feb 15 – Mar 1——
Potato—Feb 15 – Mar 8——
BasilFeb 1 – Feb 15Mar 29 – Apr 12Mar 29 – Apr 19—
Spinach——Feb 1 – Mar 1Sep 20 – Oct 18
KaleJan 18 – Feb 1Feb 15 – Mar 8Feb 15 – Mar 8Sep 6 – Oct 4
BroccoliJan 18 – Feb 1Mar 1 – Mar 22—Aug 23 – Sep 6
Peas——Feb 1 – Feb 22Sep 6 – Sep 20
EggplantJan 4 – Jan 18Mar 29 – Apr 12——
CabbageJan 18 – Feb 1Feb 15 – Mar 1—Aug 23 – Sep 6
Radish——Feb 8 – Mar 29Oct 4 – Nov 1
Strawberry—Feb 15 – Mar 8——
Beets——Feb 22 – Apr 5Sep 6 – Sep 20

Nearby cities in Texas

More: all Texas cities · other zone 8b cities: Dallas, TX, Fort Worth, TX, El Paso, TX, Virginia Beach, VA, Arlington, TX, Plano, TX, Irving, TX, Garland, TX

Carrollton gardening questions

When is the last frost in Carrollton, TX?

Plan around Mar 15. At NOAA's Dallas Ft Worth Airport, TX station, 9.4 mi from the city center, there is a 30% chance of a 32°F frost after that date. Half of springs have their last frost by Mar 8, and after Mar 26 the risk drops to about 1 in 10. A hard freeze (28°F) usually ends earlier, around Feb 25. The 90% and 10% dates are 37 days apart, close to the 36-day median for cities on this site.

When should I plant tomatoes in Carrollton, TX?

Start seeds indoors Jan 18 – Feb 1 and set transplants outside Mar 22 – Apr 5, once nights stay above 50°F and the soil is near 60°F. That leaves 245 days between the 30% frost dates, enough for most varieties including 80–85-day slicers. More: tomato planting dates by zone.

How long is the growing season in Carrollton?

About 262 days without a 32°F frost in a typical (median) year. In 9 years out of 10 the season lasts at least 236 days, and in 1 year in 10 it runs 288 days or more. In fall there is a 10% chance of frost by Nov 6 and a 30% chance by Nov 15. That ranks 24th longest of 55 Texas cities on this site.

When should I plant a fall garden in Carrollton?

Count back from the first fall frost (Nov 15): transplant broccoli Aug 23 – Sep 6; sow kale Sep 6 – Oct 4; sow lettuce Sep 6 – Oct 4; sow radishes Oct 4 – Nov 1. Hardy crops keep growing through light frosts; the median 28°F hard freeze here is Dec 7. How the math works: succession and fall planting.

Did Carrollton's hardiness zone change on the 2023 map?

Yes. Most of Carrollton was zone 8a on the 2012 map and is zone 8b on the 2023 map — half a zone warmer, like about 56% of U.S. ZIP codes. The shift comes from a newer 1991–2020 averaging period plus more weather stations and better mapping; it does not mean last frost comes earlier. Why the 2023 map is warmer.

How does Carrollton compare with Lewisville, TX?

Both are in zone 8b. The typical last spring frost in Carrollton (Mar 15) comes about 8 days earlier than in Lewisville, TX (Mar 23), 6 miles away, and the first fall frost is Nov 15 versus Nov 9. The two cities use different NOAA stations.