A few days after I had started acclimating my Petunias grown from seed to outside they all started seriously wilting. I was following the add an hour per day acclimation process.

The second day they got too hot and seriously wilted but bringing them back inside and watering them seemed to fix them right back up. A couple days later we accidentally watered them with 1/2 strength fertilizer when they were already moist and ever since then they have been slowly dieing. I've attached pictures in hopes someone might identify my issue. Was it too much water, too much fertilizer, a freak disease? Any thoughts on how I can bring them back to life? I also have impatiens and salvia that are fairing fine after undergoing the same routine.

Thanks for the help.