How to Start Stevia From Seed
Stevia is a tender perennial usually grown as an annual in much of the United States. Starting seed indoors is helpful because its seeds are small and young plants grow slowly at first.
Start indoors or direct sow?
Start stevia indoors and transplant after frost, rather than direct sowing in most gardens. Indoor starting provides the warmth and steady moisture needed for better establishment.
When to start Stevia seeds
Sow indoors about 8 to 10 weeks before the average last spring frost. Move plants outside only after frost danger has passed and soil and nights have warmed.
How to sow the seeds
Surface sow or barely cover seed, about 1/16 inch deep, in a fine, sterile seed-starting mix in shallow cells or small pots with drainage. Press seed gently into the moist mix and cover the tray with a humidity dome until sprouts appear, then remove it.
Germination
Expect germination in roughly 7 to 21 days, though seed germination can be variable. Maintain warm, evenly moist soil around 70 to 75 F, without keeping the mix waterlogged.
Seedling care
Provide bright light immediately after emergence, ideally with grow lights, and water carefully from below or at soil level. Keep good airflow, allow the surface to dry slightly between waterings, and pot up crowded seedlings to prevent damping off and root stress.
Transplanting & hardening off
Harden plants off for 7 to 10 days, then transplant after frost into a sunny, well-drained site. Set plants at their original depth, about 18 to 24 inches apart, and protect them if a late cold night is forecast.
Tips
Use fresh seed from a reliable source, since viability drops quickly and germination may be uneven. Pinch young plants lightly after they establish to encourage branching.
General seed-starting guidance for US home gardens; timing depends on your local frost dates and variety. Page updated Aug 4, 2026.