Seed Starting Calendar for Texas

Count back from the median last frost where you garden. At Dallas (Dallas Love Field) that date is March 2, so for spring 2027 onions start indoors Nov 24 to Dec 8, peppers Jan 5 to Jan 19 and tomatoes Jan 12 to Jan 26. Across Texas's 458 NOAA stations the median last frost runs from Jan 25 to Apr 16 for the middle 90 percent, so a garden near Dalhart 6 SW starts later than one near Port Isabel.

It depends on the station. The earliest median last spring freeze in Texas is January 3 at Port Isabel; the latest is April 28 at Dalhart 6 SW. A median is a coin flip: at Dallas the last 32°F freeze comes after March 2 in half of years, and has passed by March 19 in 9 of 10 years (NOAA 1991 to 2020 normals).

UNH Extension sets tomatoes out 1 to 2 weeks after the last frost, which at Dallas is Mar 9 to Mar 16 in 2027. Tomatoes are frost tender, so the date to watch is March 19, when 9 of 10 springs at Dallas have had their last 32°F night. Hardening off starts two weeks before setting out (Feb 23 to Mar 9).

Texas A&M AgriLife Extension Service's Texas Home Vegetable Gardening Guide puts it this way: "Plant your garden as early as possible in the spring and fall so the vegetables will grow and mature during ideal conditions." The guide is linked below with the date it was read (September 21, 2026).

UNH Extension gives 8 to 10 weeks from seed to transplant for both, and sets peppers out 2 weeks after the last frost and eggplant 2 to 3 weeks after, so the sowing date is 6 to 8 weeks before the median last frost. At Dallas that is Jan 5 to Jan 19 for peppers.

About two weeks. University of Missouri Extension: "Hardening should be started about two weeks before planting in the garden." University of Minnesota Extension adds that seedlings should go out on a cloudy day or in the late afternoon.

McAllen in the Rio Grande Valley reaches its median last frost around Jan 9, Houston around Jan 30, Dallas around Mar 2, and Amarillo on the Panhandle around Apr 13, three months apart. Each station carries its own dates: McAllen Miller Intl Airport Jan 9 and Amarillo Apr 13 at the median.