Answer: In many cases, the flowers are pollinated by insects and, assuming you are growing only one variety of it and it is a strain that is both viable and stable, you would simply collect seeds from the best plants. The seeds should be allowed to mature on the plant (the flower dies and dries, the seeds inside also dry and eventually become loose indicating they are "ready"). Make sure the seed is very dry, then label and store in a cool dry location until next year. For more detailed information, you might want to look at a book on the subject because this is a popular hobby and there is some interest in breeding for new varieties. One I like is "Seed Sowing and Saving : Step-By-Step Techniques for Collecting and Growing More Than 100 Vegetables, Flowers, and Herbs"
by Carole B. Turner ISBN: 1580170013.
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