Instead of deadheading your marigolds, let spent flowers remain on the plant to dry. As the seed head matures, it will turn brown. To catch seeds you can place a paper bag underneath the spent blooms, but it is not always necessary. Once the seed pod is dry, remove them from the plant and allow to air dry for a few days. Then you can harvest the seeds from the pod and put in an envelope until you are ready to plant in the spring.
Hi Karen,
Instead of deadheading your marigolds, let spent flowers remain on the plant to dry. As the seed head matures, it will turn brown. To catch seeds you can place a paper bag underneath the spent blooms, but it is not always necessary. Once the seed pod is dry, remove them from the plant and allow to air dry for a few days. Then you can harvest the seeds from the pod and put in an envelope until you are ready to plant in the spring.