Question: Do you have any tips for starting flowering tobacco (Nicotiana) from seed?
Answer: Seed of all nicotiana species should be started by the end of March. The seed is fine as dust. Scatter it very thinly over a sterile potting mix in a container. Press the seed in lightly but do not cover them. They need light to germinate. Keep the mix moist. Tiny plants will appear in 10 days or so. Prick them out once they have 2 or 3 sets of true leaves and repot them individually in larger pots. Grow them in bright light at about 60°F until the soil outside is workable, then harden them off and plant them in the garden.
Once nicotiana has been grown in the garden, seedlings will appear in subsequent years, even in Zone 4. Stands of these volunteer seedlings should be thinned or transplanted. They will develop slowly and won't bloom until mid- to late August. At the end of the summer, the smallest seedlings can be potted and kept in a sunny but cool windowsill. Feed them weekly with weak liquid fertilizer and they will bloom into December. Then cut them back hard for another bloom in the spring.