Hi and welcome to NGA
@everydayjess
It is rather hard to say "Oh it is...." but, here is a link that describes the diseases Sunflowers are susceptible to. I hope this is of use to you. It has pictures and how to control the problem. Some plant diseases/problems can be regional so it would be beneficial to add at least your state and zone, or country and zone to your profile. To do so, click on the person icon at the top left of the page to access your profile/
https://www.plantvillage.org/e...
