Julia,

Keep in mind that one seldom gets 100 % germination. The most critical condition for successful germination is the need for moisture to reach the endosperm. Scarifying (nicking) of the hard outer coat of the canna seed allows this to occur. Growers often do not scarify completely through the hard coat. If germination is delayed, consider nicking the seeds coat again. Keeping the soak warm aids in this process but is not absolutely necessary.
The time necessary can vary but usually takes place within a few days/week. Soaking the seeds until swelling occurs is advisable but change the water often to prevent bacteria. Some find the use of a fungicide helpful. Sterile media should be considered throughout the early stages of germination and growth. I have seen delayed germination after two weeks but the resulting seedlings are often weak or unhealthy.
I do not plant until actual growth has occurred.

Kent

Kent:
I started another 3 seeds using the same process but this time I added peroxide to the water much like I do with daylily seeds. 2 seeds germinated (showing radicle/white nub) so I planted those.Still waiting on the last one.
I will next time remember your suggestion to re-nick the seeds if they don't show the nub.

I use seed starting mix (Promix BX) which is the same I use for my daylily seeds. So far, the seedling that germinated on the first go round is growing under my grow lights and is doing well.

Julia

I have a hard time scarifying seeds, I am always afraid I'm going to cut myself, so I usually don't bother. I put my canna seeds in hot but not boiling water in a closed clear container, usually a water bottle. Change water daily, using hot water every time. Remove when radicle appears. Last year, I had some that refused to show radicle, so I planted them anyway, and they sprouted just the same as those that did. I had 100% germ that way, but I had a small sample, only 5 to 10 seeds.

There are numerous recommendations for scarifying canna seed. Some of us may have several hundred to do and but most have only a few. Without scarifying, germination becomes haphazard and prolonged.
For those doing only a few, I recommend holding the canna seed with a pair of common household pliers and vigorously abrading the seed on course sandpaper. This is safe and effective. If you have several, consider using a common electric bench grinder (low speed) with the seed held firmly by the pliers (use proper eye protection).

Kent

livsauntieshel: Were you starting them indoors? Using a heat mat or what method?
I too found the nicking a bit hard but used a pairs of pliers to hold them and then used a file to get to the point of seeing the white.
The 1 seed left still has not germinated so I may just toss it. I'm just experimenting and don't want to waste growing space. Nothing showing yet from the others I planted and the 1 that is growing is doing good still.

I also read something but can't find it now, about a dimple on the seed and not to nick on that area? Has anyone seen a dimple on their seeds?

Julia

Yep, indoors in a southern window in winter. No heat mat, just covered the pots with plastic baggies to keep in the humidity. In coir, with no fertilizer or special seed starting mix.