Question
Hi,
I am from India and presently the winter season has gone and spring has set in. Please advise me how I can save the seeds of flowers such as Sweet Williams, Gazenia, Dianthus, Cineraria, Salvia and Marigolds for the next flowering season. Thanks.

Sanjaya Kala, Allahabad, India

Answer
Each of these plants is its own answer.  We'll go over Sweet William, the first plant on your list.

First, let the flowers go to seed.  Then, when they are dried out have matured, pick them off (by the seed pod).  Store the pods in a plastic bag.

Dry out the seeds and pods thoroughly -- on top of the refrigerator, tucked inside a brown paper bag, is ideal.  Avoid plastic for this; you want air to reach the seeds.  When they have finally dried, they will be very tiny.  Store in a container with a strong seal.

Keep the dry seeds in a tight container, label the container and store the seeds until spring. They should be kept in a cool, dry place where the temperature is fairly consistent. It's fine to store them in the refrigerator as long as the container is tightly sealed so the seeds will remain dry.

Remember that Dianthus barbatus (commonly, "Sweet William") can be a finicky flower, sometimes requiring 'vernalization' - a cold season treatment, given subsequent to sprouting.  The 'Barbarini' series of Sweet William is one of the few exceptions, bred to bloom without exposure to brisk temps. To grow: www.aces.edu/pubs/docs/A/ANR-131

Thanks for writing,

L.I.G.