Select healthy plants for collecting seeds. Allow some flower heads to remain on the plant and dry naturally after the flowers are spent.
Cut the seed heads off the plants on a dry day using garden shears. Once the petals have dried and dropped off the flower, and the head is dry and covered with fuzz, cut the seed heads.
Place the seed heads in an open paper bag and keep in a dry room with good air circulation for at least one week. The seeds will begin falling off the head into the bag as they dry.
Mark the bag with the variety, color and date collected, using a marker.
Remove the seed heads from the bag after they are completely dry, shaking off any loosened seeds into the bag.
Hold the seed head over a bowl, and remove any chaff, dried leaves or other particles.
Combine the seeds from the bag with the seeds in the bowl.
Pour the seeds into a clean jar and put the lid on.
Mark the lid or attach a tag identifying the variety and color of mum.
Store the seeds in a cool room until it is time to plant in spring.