Pirl here, known to my husband and friends as Arlene, and known to the dog as "the person who feeds me" . Zone 7, here on eastern Long Island, seems ideal for growing dahlias and we had them growing past mid-November in 2015. For years I was content with a dozen or less but as of last year I had about 60 dahlias and hope to grow no more than that. Digging in fall becomes more and more of a daunting task.