Peace lilies (Spathiphyllum) are dark green, hardy plants that sprout large, white flowers. The stems grow from one central clump. Generally grown as houseplants, peace lilies can get as big as 6 feet tall and 5 feet wide. The plants are tolerant of low humidity and low light levels. Peace lilies grow slowly and need moist soil to keep its leaves from drooping. If you want to propagate your peace lily, it is easy to collect the plant's seeds.
Wait for your peace lily to flower. Peace lilies generally bloom in the summer, but a peace lily that is in good health and kept in a warm environment may also bloom at other times of the year.
Examine the interior of the peace lily's white flowers. The interior of each flower will contain a pod in its center. If the pod is green, the seeds are not ready to harvest. The pods will eventually turn brown and then black.
Cut off the pod when it has turned black. Use scissors or a knife to make a clean cut instead of twisting or ripping off the pod.
Scrape the seeds off the pod with a spoon, a knife or a nail file. You can also use tweezers to pluck them off if preferred. Keep the seeds in an envelope until you are ready to use them.