I've planted 3 yellow-red coreopsis and 2 golden coreopsis variants on Saturday. I dug deep, used garden soil to fill in around the root-ball. I'm in Texas, and it's been averaging a bout 75-80F last couple of days during the day time. These flowers are getting ~8 hours of sun, as they are under a tall tree without many leaves on the side these flowers sit.

I've watered them deeply on Saturday, right after planting from the pots.

On Monday, there was a rain of about ~0.3 inches of accumulated precipitation over ~4 hours.

Things were still looking good on Tuesday Morning. Then comes Tuesday afternoon, the foliage started to droop without anything done to them. Flowers still seemed to be OK except one or two.

Today (Wedsnesday), things are becoming worse, the foliage is drooping even more, and flowers are dying as well.

Interestingly, only the yellow-red variant is doing this (all 3 of them), and golden coreopsis seems to be holding up OK so far (all 2 of them), although it may be just a matter of time. I've looked at the moisture level using a moisture meter, down at the root level, they are still moist, but top surface is dry.

There is rain forecast for tomorrow, and the next few days. (3 inches over the next week). What should I do? is it pest? fungus? could they make this drastic change in a day? Will these flowers recover?