Start indoors or direct sow?

Start thyme indoors and transplant it, especially where the growing season is short. Direct sowing is possible after frost, but tiny seedlings are easily outcompeted by weeds.

When to start Thyme seeds

Start indoors 8 to 10 weeks before the average last spring frost. Direct sow outdoors after frost when the soil has warmed, if you choose not to transplant.

How to sow the seeds

Surface sow or cover seeds with only a very thin layer of sterile seed-starting mix, about 1/16 inch deep. Use cells or shallow trays with drainage, firm the mix before sowing, and mist carefully so seeds are not displaced.

Germination

Seeds usually germinate in 14 to 28 days at roughly 65 to 75 F. Keep the surface consistently moist but never saturated.

Seedling care

Provide bright light immediately after emergence and use a fan or gentle airflow to keep stems sturdy. Bottom-water when practical, thin crowded seedlings, and avoid prolonged wetness to prevent damping off.

Transplanting & hardening off

Harden off seedlings for 7 to 10 days, then transplant after the last frost into full sun and well-drained soil. Plant at the same depth they grew in their cells.

Tips

Do not bury thyme seed deeply, it needs shallow sowing for reliable emergence. Clip only lightly during the first season so young plants can establish roots.

General seed-starting guidance for US home gardens; timing depends on your local frost dates and variety. Page updated Aug 4, 2026.