2. If harvesting seeds from cactus pods, gather the pods. Remove the pods or fruits from the cactus before they dry out. The pods should not be full of moisture but should still be damp to the touch inside. The seeds themselves, which are inside the pod or fruit can vary in appearance from cactus to cactus. Some seeds will be discrete black or reddish dots clearly visible from one another, while other seeds can be so small as to appear like sand or dust.
One good indicator of maturity is in how the pod comes off of the cactus. "Ripe" pods with mature seeds should come off with a slight twist of the hand, leaving the interior fiber/cotton on the cactus.