Hello! My calendula, cosmos, zinnias, poppies, and some other flowers have been getting sick this season. The stem beneath the flower gets brown and dry, and then the flower droops and dries out. I have also notices a dark fungus that seems to be covering the seed pods. When I crumble it the seeds turn to black dust. It's a mystery to me! Hopefully I haven't just been spreading the problem every time I crumble a seed pod. The first photo is of a calendula flower, the second photo is of calendula seed pods, the third photo is of a poppy seed pod. Thank you for your help!