Frillylily: I don't think "weeks" of 90's plus humidity spells doom for Dahlias. Here our 90's start in mid May and go until at least the first of October (95 yesterday at the end of September). I'd certainly give them a try in your area. They are so beautiful and have so many intriguing forms. They held a Dahlia show at the fall fair a million years ago, and I was astounded by the beauty and variety of Dahlias. Most of the growers though were from further north then Tulsa.............Maryl