Generally, seeds are started indoors six to eight weeks before the last frost of the season. Starting the seeds earlier in the fall allows them more time to grow, making the plants stronger when it comes time to put them outside in the spring. Additionally, some plants can be kept in containers indoors for harvesting year-round.
Fill 2-inch peat pots or trays with potting soil. Place three or four seeds on top of the soil in each pot and cover loosely with 1/4-inch potting soil. Thyme seeds sprout in 14 to 21 days. When plants reach 2 to 3 inches high, transplant them to larger containers or prepare them to transplant outdoors in the spring.
Thyme is difficult to grow from seed and should not be sown directly outdoors. Plant several small containers indoors, and slowly adjust them to being outdoors before transplanting. Consider starting with transplants, divisions or cuttings for successful growth.