Question
Can you take the seed from the dead flowers and plant them, or do they have to be grow from a bulb ?

Answer
Canna can be propagated from seed, but it takes three years before they form a bulb large enough to produce flowers. Your best bet is to dig up the bulb and store it in peat in a cool place over the winter, such as a garage or basement. If you leave them in the ground over the winter, they will die.

Good luck, and please write again if I can ever be of assistance.

Regards,

Mike