Q.Black Eyed Susans
They seem to be bending and dying earlier this year. Why?

Certified GKH Gardening Expert
Unfortunately, your photo did not come through. Wilt can be attributed to many things, from disease to pests nibbling on the roots, even to heat!
What I can do, in the meantime, is point you to an article that will help you with their care. This can help you rule out environmental factors, knowing that you are providing proper care.
https://www.gardeningknowhow.com/ornamental/bulbs/dahlia/dahlia-care-grow-dahlia-plant.htm