Asked February 23, 2021, 1:33 AM EST
Arapahoe County Colorado
Thank you for reaching out with your question.
I have attached a planting guide from the USDA on Lobelia. It includes information on seed starting. No cold stratification is needed and no scarification is indicated.
Note that Lobelia germinates best at temps of 70° or above. Germinations is approximately 20 days.