They will produce flowers the first year. I'm not sure about multiple stalks though!

The productive of any unknown canna seedling is first and foremost based on its genetic parentage. Most seedlings are often less viable plants but a very few prove to be somewhat superior. It really is a mater of chance and typically the results are "in the eyes of the beholder".
That "rare" seedling will exhibit traits worthy of continued trials and should produce blooming stalks that rival its parentage. Once in a great while it will outperform its many siblings or parents.
Please keep in mind that all hybrid seedlings are unique and different than their parents. Most should produce multiple stalks and blooms in one full growing season. The length of the growing season and environment will be a factor, but the best ones will produce a plant equivalent to a planted rhizome.

Regards,
Kent

Thanks redthreaddiy and Kent!

I am looking forward to seeing what comes up. :C)

I am curious, as to how your canna turned out. I WS'd and 1 survived it is huge! Yet, to bloom. I was wondering how did yours turn out?

Hi Ladyrose65,

I tried to start perhaps 20 seeds in March and 15 of them germinated. I grew them under lights and put them outside in pots around mid May. They were already about 15 inches tall. The bed that I wanted to prepare for them never got finished, so I put the pots in the area and the roots grew out of the drain holes and into the ground. They are Huge!!!!

Each pot has 4 to 6 stalks, so I probably have about 100 full sized plants. I got a lot of flowers and there are buds still coming up from the latest stalks. I am thinking I have the flowers due to the fact that I started them early indoors and that they are in FULL sun. Never a shadow is cast on them.

Canna2grow, Kent, was correct in his reply to me above. Only a few were as nice as the plants that I took the seeds from. Most of the flowers were not as full and color not as deep a red as the parents. I wonder if the fullness of the flowers would have been better if the plants were in the ground without the pots. I would like to get nice looking plants, but I am afraid of getting one with a virus. One thing I am sure of, I am going to have a hard time getting the rhyzomes out of the pots.

Ken