Hi Catherine, Hi Anne,
Could I suggest sand paper to rub down the coat of the canna seeds. It is easier to use and less dangerous to your fingers, though of course the seeds can bounce away any way.
Grew about a dozen from seed this first year, stopped them in 9cm pots so they did not get too big. Grew them inside the garden house to start them early.
About to set them inside again for the winter.
Really enjoyed the other ten or so I bought as plants, wonderful leaves, beautiful colours. First year growing them and no problems this year.
May have a serious go next year.
All the best,
Peter