I am trying to find out why my sunflower heads are not flowering. Out of a dozen plants that came up, only one has actually flowered. Is there somewhere I can find pictures of what various pests do to sunflowers? I have tried to upload two pictures of the heads. Any hints would be greatly appreciated. Thank you in advance.
Sunflower Heads Are Not Flowering
Certified GKH Gardening Expert
This is most likely due to the Sunflower Midge insect.
I would recommend you contact your County Extension Office to inquire on the best treatment in your region.
Here are some links for you with more information.