I overwintered 27 Dahlias grown in individual pots (10") under my carport. They did not get frostbitten. I have watered the Dahlias a week ago & they are still under my carport in fairy warm conditions. The stalks have shrivelled up & look dead. I have lifted one plant & it had tubers, about the size of a grape.
How do I know if these plants are alive or dead? If the plants are alive when should they start showing signs of life?
Note! I have since read that you should wait till the first frost & the plant turns black before cutting back & overwintering. These plants did not turn black but were cut back about end September before first frost.