This is interesting to say the least. What you discribe sounds like Fusarium wilt, but Celebrity is resistance to both Verticillium wilt and Fusarium wilt. However, it is not resistance to Walnut wilt. If your purchased potting soil had any black walnut roots ground up into it then this would happen. The soiless mixture you are using did you use it last year? I'm not a big believer in Miracle-Gro. What else are you feeding your
plants?
Temperatures over 100 degrees can cause your
flowers to die and fall off. While we have not seen 100 degress where I live, in the corner of my entry way to the house in the afternoon the heat radiats/ collects there and it goes well over 110 degree many afternoons. Perhaps you have this same situation.
Next what I'm going to say will bring down upon my head
every Celebrity grower on this site. I don't care for Celebrity. I tried them three times. They never product well for me and they seem to die early.
Suggestions? Well I know you are fustrated person. As such I believe we need to get you on to a season of success. What I suggest is you purchase an Earthbox.
http://www.earthbox.com While I'm totally an organic gardener, I'm going to look the other way when I will suggest you follow their program. Follow their program. Or if you want to go totally organic I can help you there. It is not really any harder. You just have to mix your own fertilzer. Next, if heat is a problem on your deck then I suggest trying out Burpee's Heatwave tomatoes.
Heatwave There are several heat-resistant varieties besides Heatwave. Those with medium to large fruit are: Homestead 24, Merced, Solar Set, Spitfire, Sun Chaser, Sunmaster, Sunny, Surefire, Terrific and Viva Italia. The small fruit ones are: Gardener’s Delight, Grape, Husky Cherry Red, Jolly, Juliet, Small Fry, Sugar Snack, Sun Cherry, SunGold, SuperSweet 100 and Sweet Chelsea.
Burpee is claiming that Heatwave will set fruit @ 100 degrees; however, I read two studies where it set fruit at 117 degrees. I have grown them here in the summer along with other heat tomatos. My summers are hot. Not a bad fruit. About 8-10 ounce.
Sorry I could not be of more help. Perhaps Phil can when he see this thread.