Yesterday I checked the feeder for mold. It had mold growing on the yellow flowers inside the feeder! Those flowers have little places where the mold is dificultnto get out. I used a white pen to show where the openigs are and hope that's enough. Soaking the flowers in vinegar, but will need to remove the mold with a toothpick. Time to go to the local nursery and see what I can grow in pots.