I winter sowed some Viola Fuji Dawn last year and the plants are healthy and growing like mad. The only problem is that it never flowers but makes tons of seed pods. I have gone out of all time of day but the blooms never open with a flower they just make seeds. Why is that?
That's what I thought too. It became an obsession with me. I went out everyday, all times of the day. Hate to admit I even went out with a flashlight thinking it was some weird night bloomer or early morning bloomer. I'm telling you each plant had several flower stems and then went straight to seed pods. Not one bloom! I even had a friend look with me. Her answer was to rip them out. I left a few over the winter to see what happens this year. I'm still checking on them. So far no stems but I'll keep you posted.
A lot of species violets produce viable seed from closed, self-fertilizing flowers, often hidden underground. When I dig out a clump of Viola sororia rhizomes, they're often surrounded by little blanched stems with pods of seed. Showy hybrid violas don't seem to do this as much, perhaps because self-fertilizing flowers don't hybridize, though they can produce sports. To get those amazing new colors and combinations, though, takes flowers that can be crossed.
The ones that produce closed, hidden flowers seem to make zillions of them, and some years may not make any showy flowers. I'm glad 'Fuji Dawn' came through for you eventually.