US Grow Zones

Plano, Texas: planting zone & frost dates

Last updated · Sources: PRISM/OSU 2023 ZIP zone listings; NOAA NCEI 1991–2020 Climate Normals (station USC00417588); U.S. Census Bureau — see methodology

Plano 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 14 and the first fall frost around Nov 13.

Hardiness zone8B15 to 20°F
Last spring frostMar 1430% chance of frost after
First fall frostNov 1330% chance of frost before
Growing season259 daysmedian frost-free days

Frost dates

ProbabilityLast spring frost (32°F)First fall frost (32°F)
Safer (10% risk)Mar 29Nov 2
Typical planning date (30% risk)Mar 14Nov 13
Median (50%)Mar 7Nov 21

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 RICHARDSON, TX (USC00417588), 3.8 mi (6.1 km) from the city center and 33 ft lower than the city center (-10 m). Record used for the 1991–2020 normals: 11 years.

Frost probability in spring and fall, Plano, TXChance of a 32°F frost in Plano, TX, NOAA 1991–2020. Spring: the chance of another frost falls from 90% on Feb 18 to 10% on Mar 29. Fall: the chance that the first frost has arrived rises from 10% on Nov 2 to 90% on Dec 9.0%50%100%Spring: later frostFeb 1Mar 1Apr 130%: Mar 14Fall: frost arrivedNov 1Dec 1Jan 130%: Nov 1332°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 USC00417588.
Frost-free growing season in Plano, TX1 in 10 risk: Mar 29 to Nov 2 (218 days); 3 in 10 risk: Mar 14 to Nov 13 (244 days); Median (50%): Mar 7 to Nov 21 (259 days); No 28°F freeze: Feb 24 to Dec 4 (283 days). In 9 of 10 years the 32°F-free season is at least 232 days.Frost-free days, spring to fallJFMAMJJASOND1 in 10 risk218 days3 in 10 risk244 daysMedian (50%)259 daysNo 28°F freeze283 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 Plano

All 6 ZIP codes covering Plano are in zone 8b.

ZIP codes in Plano and their zones
ZIPZoneShare of city land
750748b22.2%
750938b19.7%
750248b17.4%
750758b13.4%
750258b13.3%
750238b12.8%

Vegetable planting calendar for Plano

Dates are counted from the 30%-risk frost dates above (last frost Mar 14, first frost Nov 13). Shift a week later in cold spots or low-lying ground.

CropStart indoorsTransplant / plant outDirect sowFall crop sow/plant
TomatoJan 17 – Jan 31Mar 21 – Apr 4——
PepperJan 3 – Jan 17Mar 28 – Apr 11——
LettuceJan 31 – Feb 14Feb 28 – Mar 21Feb 14 – Mar 28Sep 4 – Oct 2
Green Beans——Mar 21 – Apr 25Aug 21 – Sep 4
Sweet Corn——Mar 21 – Apr 18—
Zucchini & Summer SquashFeb 14 – Feb 21Mar 21 – Apr 4Mar 21 – Apr 11Aug 21 – Sep 4
CucumberFeb 14 – Feb 21Mar 28 – Apr 4Mar 21 – Apr 11Aug 21 – Sep 4
Carrot——Feb 21 – Mar 28Aug 21 – Sep 4
OnionDec 20 – Jan 3Feb 14 – Feb 28——
Potato—Feb 14 – Mar 7——
BasilJan 31 – Feb 14Mar 28 – Apr 11Mar 28 – Apr 18—
Spinach——Jan 31 – Feb 28Sep 18 – Oct 16
KaleJan 17 – Jan 31Feb 14 – Mar 7Feb 14 – Mar 7Sep 4 – Oct 2
BroccoliJan 17 – Jan 31Feb 28 – Mar 21—Aug 21 – Sep 4
Peas——Jan 31 – Feb 21Sep 4 – Sep 18
EggplantJan 3 – Jan 17Mar 28 – Apr 11——
CabbageJan 17 – Jan 31Feb 14 – Feb 28—Aug 21 – Sep 4
Radish——Feb 7 – Mar 28Oct 2 – Oct 30
Strawberry—Feb 14 – Mar 7——
Beets——Feb 21 – Apr 4Sep 4 – Sep 18

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, Irving, TX, Garland, TX, Frisco, TX

Plano gardening questions

When is the last frost in Plano, TX?

Plan around Mar 14. At NOAA's Richardson, TX station, 3.8 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 7, and after Mar 29 the risk drops to about 1 in 10. A hard freeze (28°F) usually ends earlier, around Feb 24. The 90% and 10% dates are 39 days apart, close to the 36-day median for cities on this site.

When should I plant tomatoes in Plano, TX?

Start seeds indoors Jan 17 – Jan 31 and set transplants outside Mar 21 – Apr 4, once nights stay above 50°F and the soil is near 60°F. That leaves 244 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 Plano?

About 259 days without a 32°F frost in a typical (median) year. In 9 years out of 10 the season lasts at least 232 days, and in 1 year in 10 it runs 285 days or more. In fall there is a 10% chance of frost by Nov 2 and a 30% chance by Nov 13. That ranks 27th longest of 55 Texas cities on this site.

When should I plant a fall garden in Plano?

Count back from the first fall frost (Nov 13): transplant broccoli Aug 21 – Sep 4; sow kale Sep 4 – Oct 2; sow lettuce Sep 4 – Oct 2; sow radishes Oct 2 – Oct 30. Hardy crops keep growing through light frosts; the median 28°F hard freeze here is Dec 4. How the math works: succession and fall planting.

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

Yes. Most of Plano 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 Plano compare with Allen, TX?

Both are in zone 8b. The typical last spring frost in Plano (Mar 14) comes about 13 days earlier than in Allen, TX (Mar 27), 6 miles away, and the first fall frost is Nov 13 versus Nov 5. The two cities use different NOAA stations.