Are ants causing my flowers to die?

Question:

I have a happy, healthy bed of annual flowers- cosmos, Mexican sunflowers, zinnias, verbena. I moved a wooden plank into the garden to create a border for the bed. I noticed there were small ants in the board. Since then, my annuals have been wilting and dying and the base of the stem of them is girdled.  Also, it’s not all the annual plants that are dying, only one at a time. As soon as one dies, it seems they love on to the next. Are the ants responsible for this? Why do ants do this? What could be another explanation? 

Answer:

Donna R. Coffin, Extension Professor

It sounds like a combination of things happening, but the ants are not responsible. We think it is a combination of disease affecting plants that are stressed by the drought. Hopefully your garden has gotten a lot of rain. Generally gardens need 1 to 1-1/2 inches of water a week, whether from the sky or irrigation. We have a website and video on how to water your garden that you might find interesting.