Stage I Starts with the radicle breaking through the testa. The roots are touching the medium. Ends with fully developed cotyledons.
Stage II Starts from fully developed cotyledons. Ends with the fully developed true leaf or true leaf pair.
Stage III Starts from the fully developed true leaf or true leaf pair and ends with 80% of the young plants being marketable.
Stage IV All young plants are ready for sale and in the process of being hardened off. This stage lasts about 7 days.