Dahlias the gems of the garden

摘要

The first hard frost in western Pennsylvania last year was October 19, 2009. Our average first frost date is October 16th. We got an extra three days last year. I had a dahlia that had just bloomed a few days earlier, so I was able to appreciate it alittle while longer. This season I started them earlier in the greenhouse. Dahlias are considered annuals here in zone 5. They produce tubers during the growing season. They cannot tolerate frost. They must be dug up in the fall and stored for the next season. If they are left in the ground they will rot.