Every plant in one spot wilts but not it's neighbors

[lakelady]

I am having a weird scenario I can't figure out. Early on, I had put a Verde Claro plant in a hole along a row, and within a month, it wilted and would not come back. I pulled it, and replaced it with Indian Stripe PL. That was about 6 weeks ago. Now IT also is wilting for no known reason. It has a Brandywine Croatia next to it that is over 7' tall and doing fine, and the neighboring plant on the other side is doing just fine too. I think something odd is going on with just that one spot. The tomatoes are about 3' apart, but this one spot seems to have something bad going on.

I thought the first plant in that hole was just sick or weak. Now I'm wondering what on earth could cause this to happen to replacement. I have never planted tomatoes in this spot, ever. It was wildflowers before this. No disease at all on the leaves or signs of disease anywhere. I'm not sure what to do with it. Very few flowers on the plant ,and only one tomato growing that I'd like to be able to taste!

Suggestions? Ideas?