Question From: s. Clow - CALIFORNIA
Q: Hi Nancy, My marigolds have black buds inside the bloom. There are no webs (like mites) and they are in a pot with new soil. I had them last year too but the local nursary didn't have an answer. I've search the web without luck. I'm hoping you can help Identify and let me know what I can do to avoid them next year. Note: the 2nd image shows the bud shriveled.
I think your plants have a fungal disease called black root rot. Take those photos (they did not come through) to and independent garden center or nursery for an accurate ID and control. Plants, roots and all should be removed and destroyed. Do not replant in the same soil. Best And Happy Yardening, Nancy.