Yes, I know your tomato seedlings are burning a hole in your pocket.
No, it’s not a good idea to plant yet.
Here’s why:
Tomatoes cannot survive a frost. Not even a “slight” frost. Even temps below 50°F make tomatoes unhappy.
Today, March 12, is the official average last frost date for DFW. This means that frosts can happen before this date and after this date. I never plant before March 12.
Starting around March 8, I watch the weather forecast like a hawk. Last week, I thought that tomatoes could go in this week, but that isn’t the case anymore.
Frost in forecast
Current forecast predicts a low of 37°F on Sunday. This is well within the temperature range when frost can occur. (For nerdy explanation of this phenomenon, see below.)
Don’t worry. As long as we get our tomatoes in before April 1st, we’re fine. There’s no need to risk dead tomato plants by rushing.
Already planted?
If you already planted your tomatoes, you will need to cover them on Sunday, maybe even Monday as well.
More tomato help
If you need more help with growing tomatoes, my Trouble-Free Tomatoes Class held on March 7 is available for replay. Learn how to grow blue ribbon-worthy tomatoes, and get unlimited additional help from me with your tomato queries. Learn more about enrollment here.
Frost explained
Frost happens when the temperature at ground level drops below 32°F, causing moisture in the air to condense and form ice crystals on surfaces, even if the air temperature is above freezing.
Frost can occur even when air temperatures are close to 40°F due to a phenomenon called radiational cooling.
At night, especially under clear skies and calm conditions, heat from the ground radiates back into the atmosphere, cooling the surface more quickly than the surrounding air. This can cause temperatures at ground level to drop below 32°F, even if the air temperature a few feet above the ground is warmer.
Make this your best garden year yet
The 2026 North Texas Garden Planner explains how to grow a beautiful garden in DFW and keeps you on track with planting dates and schedules.