Cover the flower heads with a paper bag secured to the plant with string or twine, and then hang the bundle upside down in a dry, dark place like an attic.

The seeds will collect at the bottom of the secured brown paper bag. Shake the bundle well to release the seeds from the flower heads. Many gardeners like to save seeds they have collected from their own herb gardens.

This way they have plenty of seeds to plant the next year.

Place the airtight container in a dark place until the seeds are used.. Bind the ends of the stems together with a strong rubber band or string. When the seeds are fully ripe and fragrant, it is time to collect the seeds. In a couple of weeks, take the plant bundle with the covered flower heads down. You will be able to use your saved seeds for the next gardening season if you store them in paper packages or envelopes in an airtight container. Looking for ripe seeds to collect is a pleasant experience, and you will have lots of seeds to snip off and save for planting during the next gardening season.

When the flowers of the plant are nearly fully ripe, cut the plants' stems at the base.