When to Direct-Sow Heirloom Tomato Seeds Outdoors

Eager to skip indoor seed-starting and sow heirloom tomato seeds straight into the garden? The key is soil temperature. Tomato seeds germinate best when the soil reaches at least 70°F (21°C). In many parts of Georgia, that threshold typically arrives in late April—last year, for example, it hit 70°F around April 23. Right now, soil temperatures are lingering in the mid-60s, so it's wise to wait at least another week before planting. Use a soil thermometer to check your own beds, or monitor local weather stations like georgiaweather.net for real-time data. Once the soil is consistently warm, sow seeds ¼ inch deep, keep the bed moist, and thin seedlings to the strongest plants after they develop true leaves.