The wisteria is about 12 years old and puts on a lot of blooms. But it has never produced a seed. Can you tell me why?
Why Doesn’t My Wisteria Blooms Produce Seeds?
Wisteria is self-fertile or self-pollinating. Are insects getting to the blooms to help with pollination? If your plant(s) are blooming, you should be getting seed. Sorry, my answer is, "No, I don't know why." If you want seed for propagation purposes, you can order seed, but a seed grown wisteria can take 15-20 years to bloom.